TY  - JOUR
A1  - Morales-Lozano, Maria I.
A1  - Viering, Oliver
A1  - Samnick, Samuel
A1  - Rodriguez-Otero, Paula
A1  - Buck, Andreas K.
A1  - Marcos-Jubilar, Maria
A1  - Rasche, Leo
A1  - Prieto, Elena
A1  - Kortüm, K. Martin
A1  - San-Miguel, Jesus
A1  - Garcia-Velloso, Maria J.
A1  - Lapa, Constantin
T1  - \(^{18}\)F-FDG and \(^{11}\)C-methionine PET/CT in newly diagnosed multiple myeloma patients: comparison of volume-based PET biomarkers
JF  - Cancers
N2  - \(^{11}\)C-methionine (\(^{11}\)C-MET) is a new positron emission tomography (PET) tracer for the assessment of disease activity in multiple myeloma (MM) patients, with preliminary data suggesting higher sensitivity and specificity than \(^{18}\)F-fluorodeoxyglucose (\(^{18}\)F-FDG). However, the value of tumor burden biomarkers has yet to be investigated. Our goals were to corroborate the superiority of \(^{11}\)C-MET for MM staging and to compare its suitability for the assessment of metabolic tumor burden biomarkers in comparison to \(^{18}\)F-FDG. Twenty-two patients with newly diagnosed, treatment-naïve symptomatic MM who had undergone \(^{11}\)C-MET and \(^{18}\)F-FDG PET/CT were evaluated. Standardized uptake values (SUV) were determined and compared with total metabolic tumor volume (TMTV) for both tracers: total lesion glycolysis (TLG) and total lesion \(^{11}\)C-MET uptake (TLMU). PET-derived values were compared to Revised International Staging System (R-ISS), cytogenetic, and serologic MM markers such as M component, beta 2 microglobulin (B2M), serum free light chains (FLC), albumin, and lactate dehydrogenase (LDH). In 11 patients (50%), \(^{11}\)C-MET detected more focal lesions (FL) than FDG (p < 0.01). SUVmax, SUVmean, SUVpeak, TMTV, and TLMU were also significantly higher in \(^{11}\)C-MET than in \(^{18}\)F-FDG (p < 0.05, respectively). \(^{11}\)C-MET PET biomarkers had a better correlation with tumor burden (bone marrow plasma cell infiltration, M component; p < 0.05 versus p = n.s. respectively). This pilot study suggests that \(^{11}\)C-MET PET/CT is a more sensitive marker for the assessment of myeloma tumor burden than \(^{18}\)F-FDG. Its implications for prognosis evaluation need further investigation.
KW  - multiple myeloma
KW  - methionine
KW  - total lesion glycolysis (TLG)
KW  - metabolic tumor volume (MTV)
KW  - total lesion methionine uptake (TLMU)
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203686
SN  - 2072-6694
VL  - 12
IS  - 4
ER  - 
TY  - JOUR
A1  - Tran-Gia, Johannes
A1  - Denis-Bacelar, Ana M.
A1  - Ferreira, Kelley M.
A1  - Robinson, Andrew P.
A1  - Calvert, Nicholas
A1  - Fenwick, Andrew J.
A1  - Finocchiaro, Domenico
A1  - Fioroni, Federica
A1  - Grassi, Elisa
A1  - Heetun, Warda
A1  - Jewitt, Stephanie J.
A1  - Kotzassarlidou, Maria
A1  - Ljungberg, Michael
A1  - McGowan, Daniel R.
A1  - Scott, Nathaniel
A1  - Scuffham, James
A1  - Gleisner, Katarina Sjögreen
A1  - Tipping, Jill
A1  - Wevrett, Jill
A1  - Lassmann, Michael
T1  - A multicentre and multi-national evaluation of the accuracy of quantitative Lu-177 SPECT/CT imaging performed within the MRTDosimetry project
JF  - EJNMMI Physics
N2  - Purpose
Patient-specific dosimetry is required to ensure the safety of molecular radiotherapy and to predict response. Dosimetry involves several steps, the first of which is the determination of the activity of the radiopharmaceutical taken up by an organ/lesion over time. As uncertainties propagate along each of the subsequent steps (integration of the time–activity curve, absorbed dose calculation), establishing a reliable activity quantification is essential. The MRTDosimetry project was a European initiative to bring together expertise in metrology and nuclear medicine research, with one main goal of standardizing quantitative \(^{177}\)Lu SPECT/CT imaging based on a calibration protocol developed and tested in a multicentre inter-comparison. This study presents the setup and results of this comparison exercise.

Methods
The inter-comparison included nine SPECT/CT systems. Each site performed a set of three measurements with the same setup (system, acquisition and reconstruction): (1) Determination of an image calibration for conversion from counts to activity concentration (large cylinder phantom), (2) determination of recovery coefficients for partial volume correction (IEC NEMA PET body phantom with sphere inserts), (3) validation of the established quantitative imaging setup using a 3D printed two-organ phantom (ICRP110-based kidney and spleen). In contrast to previous efforts, traceability of the activity measurement was required for each participant, and all participants were asked to calculate uncertainties for their SPECT-based activities.

Results
Similar combinations of imaging system and reconstruction lead to similar image calibration factors. The activity ratio results of the anthropomorphic phantom validation demonstrate significant harmonization of quantitative imaging performance between the sites with all sites falling within one standard deviation of the mean values for all inserts. Activity recovery was underestimated for total kidney, spleen, and kidney cortex, while it was overestimated for the medulla.

Conclusion
This international comparison exercise demonstrates that harmonization of quantitative SPECT/CT is feasible when following very specific instructions of a dedicated calibration protocol, as developed within the MRTDosimetry project. While quantitative imaging performance demonstrates significant harmonization, an over- and underestimation of the activity recovery highlights the limitations of any partial volume correction in the presence of spill-in and spill-out between two adjacent volumes of interests.
KW  - quantitative SPECT/CT
KW  - 177Lu SPECT/CT imaging
KW  - standardization of SPECT/CT imaging
KW  - harmonization of SPECT/CT imaging
KW  - international multicenter comparison exercise
KW  - traceability of SPECT/CT imaging
KW  - molecular radiotherapy (MRT)
KW  - 3D printing
KW  - phantom
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270380
VL  - 8
ER  - 
TY  - JOUR
A1  - Eissler, Cristoph
A1  - Werner, Rudolf A.
A1  - Arias-Loza, Paula
A1  - Nose, Naoko
A1  - Chen, Xinyu
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
T1  - The number of frames on ECG-gated \(^{18}\)F-FDG small animal PET has a significant impact on LV systolic and diastolic functional parameters
JF  - Molecular Imaging
N2  - Objectives. This study is aimed at investigating the impact of frame numbers in preclinical electrocardiogram- (ECG-) gated \(^{18}\)F-fluorodeoxyglucose (\(^{18}\)F-FDG) positron emission tomography (PET) on systolic and diastolic left ventricular (LV) parameters in rats. Methods. \(^{18}\)F-FDG PET imaging using a dedicated small animal PET system with list mode data acquisition and continuous ECG recording was performed in diabetic and control rats. The list-mode data was sorted and reconstructed with different numbers of frames (4, 8, 12, and 16) per cardiac cycle into tomographic images. Using an automatic ventricular edge detection software, left ventricular (LV) functional parameters, including ejection fraction (EF), end-diastolic (EDV), and end-systolic volume (ESV), were calculated. Diastolic variables (time to peak filling (TPF), first third mean filling rate (1/3 FR), and peak filling rate (PFR)) were also assessed. Results. Significant differences in multiple parameters were observed among the reconstructions with different frames per cardiac cycle. EDV significantly increased by numbers of frames (353.8 & PLUSMN; 57.7 mu l*, 380.8 & PLUSMN; 57.2 mu l*, 398.0 & PLUSMN; 63.1 mu l*, and 444.8 & PLUSMN; 75.3 mu l at 4, 8, 12, and 16 frames, respectively; *P < 0.0001 vs. 16 frames), while systolic (EF) and diastolic (TPF, 1/3 FR and PFR) parameters were not significantly different between 12 and 16 frames. In addition, significant differences between diabetic and control animals in 1/3 FR and PFR in 16 frames per cardiac cycle were observed (P < 0.005), but not for 4, 8, and 12 frames. Conclusions. Using ECG-gated PET in rats, measurements of cardiac function are significantly affected by the frames per cardiac cycle. Therefore, if you are going to compare those functional parameters, a consistent number of frames should be used.
KW  - Myocardial-perfusion SPECT
KW  - left-ventricular function
KW  - ejection fraction
KW  - MRI
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265778
VL  - 2021
ER  - 
TY  - JOUR
A1  - Scherthan, Harry
A1  - Lee, Jin-Ho
A1  - Maus, Emanuel
A1  - Schumann, Sarah
A1  - Muhtadi, Razan
A1  - Chojowski, Robert
A1  - Port, Matthias
A1  - Lassmann, Michael
A1  - Bestvater, Felix
A1  - Hausmann, Michael
T1  - Nanostructure of clustered DNA damage in leukocytes after in-solution irradiation with the alpha emitter Ra-223
JF  - Cancers
N2  - Background: Cancer patients are increasingly treated with alpha-particle-emitting radiopharmaceuticals. At the subcellular level, alpha particles induce densely spaced ionizations and molecular damage. Induction of DNA lesions, especially clustered DNA double-strand breaks (DSBs), threatens a cell's survival. Currently, it is under debate to what extent the spatial topology of the damaged chromatin regions and the repair protein arrangements are contributing. Methods: Super-resolution light microscopy (SMLM) in combination with cluster analysis of single molecule signal-point density regions of DSB repair markers was applied to investigate the nano-structure of DNA damage foci tracks of Ra-223 in-solution irradiated leukocytes. Results: Alpha-damaged chromatin tracks were efficiently outlined by γ-H2AX that formed large (super) foci composed of numerous 60–80 nm-sized nano-foci. Alpha damage tracks contained 60–70% of all γ-H2AX point signals in a nucleus, while less than 30% of 53BP1, MRE11 or p-ATM signals were located inside γ-H2AX damage tracks. MRE11 and p-ATM protein fluorescent tags formed focal nano-clusters of about 20 nm peak size. There were, on average, 12 (±9) MRE11 nanoclusters in a typical γ-H2AX-marked alpha track, suggesting a minimal number of MRE11-processed DSBs per track. Our SMLM data suggest regularly arranged nano-structures during DNA repair in the damaged chromatin domain.
KW  - complex DNA damage
KW  - DNA repair
KW  - high LET irradiation
KW  - Single Molecule Localization Microscopy (SMLM)
KW  - DSB focus substructure
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-193038
SN  - 2072-6694
VL  - 11
IS  - 12
ER  - 
TY  - JOUR
A1  - Aerts, An
A1  - Eberlein, Uta
A1  - Holm, Sören
A1  - Hustinx, Roland
A1  - Konijnenberg, Mark
A1  - Strigari, Lidia
A1  - van Leeuwen, Fijs W. B.
A1  - Glatting, Gerhard
A1  - Lassmann, Michael
T1  - EANM position paper on the role of radiobiology in nuclear medicine
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - With an increasing variety of radiopharmaceuticals for diagnostic or therapeutic nuclear medicine as valuable diagnostic or treatment option, radiobiology plays an important role in supporting optimizations. This comprises particularly safety and efficacy of radionuclide therapies, specifically tailored to each patient. As absorbed dose rates and absorbed dose distributions in space and time are very different between external irradiation and systemic radionuclide exposure, distinct radiation-induced biological responses are expected in nuclear medicine, which need to be explored. This calls for a dedicated nuclear medicine radiobiology. Radiobiology findings and absorbed dose measurements will enable an improved estimation and prediction of efficacy and adverse effects. Moreover, a better understanding on the fundamental biological mechanisms underlying tumor and normal tissue responses will help to identify predictive and prognostic biomarkers as well as biomarkers for treatment follow-up. In addition, radiobiology can form the basis for the development of radiosensitizing strategies and radioprotectant agents. Thus, EANM believes that, beyond in vitro and preclinical evaluations, radiobiology will bring important added value to clinical studies and to clinical teams. Therefore, EANM strongly supports active collaboration between radiochemists, radiopharmacists, radiobiologists, medical physicists, and physicians to foster research toward precision nuclear medicine.
KW  - radionuclide therapy
KW  - radiobiology
KW  - dosimetry
KW  - biodosimetry
KW  - biomarkers
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265595
VL  - 48
IS  - 11
ER  - 
TY  - JOUR
A1  - Nose, Naoko
A1  - Nogami, Suguru
A1  - Koshino, Kazuhiro
A1  - Chen, Xinyu
A1  - Werner, Rudolf A.
A1  - Kashima, Soki
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Fukuchi, Kazuki
A1  - Higuchi, Takahiro
T1  - [18F]FDG-labelled stem cell PET imaging in different route of administrations and multiple animal species
JF  - Scientific Reports
N2  - Stem cell therapy holds great promise for tissue regeneration and cancer treatment, although its efficacy is still inconclusive and requires further understanding and optimization of the procedures. Non-invasive cell tracking can provide an important opportunity to monitor in vivo cell distribution in living subjects. Here, using a combination of positron emission tomography (PET) and in vitro 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) direct cell labelling, the feasibility of engrafted stem cell monitoring was tested in multiple animal species. Human mesenchymal stem cells (MSCs) were incubated with phosphate-buffered saline containing [18F]FDG for in vitro cell radiolabelling. The pre-labelled MSCs were administrated via peripheral vein in a mouse (n=1), rats (n=4), rabbits (n=4) and non-human primates (n=3), via carotid artery in rats (n=4) and non-human primates (n=3), and via intra-myocardial injection in rats (n=5). PET imaging was started 10 min after cell administration using a dedicated small animal PET system for a mouse and rats. A clinical PET system was used for the imaging of rabbits and non-human primates. After MSC administration via peripheral vein, PET imaging revealed intense radiotracer signal from the lung in all tested animal species including mouse, rat, rabbit, and non-human primate, suggesting administrated MSCs were trapped in the lung tissue. Furthermore, the distribution of the PET signal significantly differed based on the route of cell administration. Administration via carotid artery showed the highest activity in the head, and intra-myocardial injection increased signal from the heart. In vitro [18F]FDG MSC pre-labelling for PET imaging is feasible and allows non-invasive visualization of initial cell distribution after different routes of cell administration in multiple animal models. Those results highlight the potential use of that imaging approach for the understanding and optimization of stem cell therapy in translational research.
KW  - biomarkers
KW  - molecular medicine
KW  - stem-cell research
KW  - stem cells
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260590
VL  - 11
IS  - 1
ER  - 
TY  - JOUR
A1  - Toyama, Yoshitaka
A1  - Werner, Rudolf A.
A1  - Ruiz-Bedoya, Camilo A.
A1  - Ordonez, Alvaro A.
A1  - Takase, Kei
A1  - Lapa, Constantin
A1  - Jain, Sanjay K.
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Higuchi, Takahiro
T1  - Current and future perspectives on functional molecular imaging in nephro-urology: theranostics on the horizon
JF  - Theranostics
N2  - In recent years, a paradigm shift from single-photon-emitting radionuclide radiotracers toward positron-emission tomography (PET) radiotracers has occurred in nuclear oncology. Although PET-based molecular imaging of the kidneys is still in its infancy, such a trend has emerged in the field of functional renal radionuclide imaging. Potentially allowing for precise and thorough evaluation of renal radiotracer urodynamics, PET radionuclide imaging has numerous advantages including precise anatomical co-registration with CT images and dynamic three-dimensional imaging capability. In addition, relative to scintigraphic approaches, PET can allow for significantly reduced scan time enabling high-throughput in a busy PET practice and further reduces radiation exposure, which may have a clinical impact in pediatric populations. In recent years, multiple renal PET radiotracers labeled with C-11, Ga-68, and F-18 have been utilized in clinical studies. Beyond providing a precise non-invasive read-out of renal function, such radiotracers may also be used to assess renal inflammation. This manuscript will provide an overview of renal molecular PET imaging and will highlight the transformation of conventional scintigraphy of the kidneys toward novel, high-resolution PET imaging for assessing renal function. In addition, future applications will be introduced, e.g. by transferring the concept of molecular image-guided diagnostics and therapy (theranostics) to the field of nephrology.
KW  - glomerular filtration rate
KW  - renal
KW  - kidney
KW  - renal function
KW  - positron emission tomography
KW  - nephrology
KW  - urology
KW  - molecular imaging
KW  - theranostics
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260090
VL  - 11
IS  - 12
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Kuzkina, Anastasia
A1  - Lapa, Constantin
A1  - Mammadova, Sona
A1  - Buck, Andreas
A1  - Volkmann, Jens
A1  - Sommer, Claudia
A1  - Isaias, Ioannis U.
A1  - Doppler, Kathrin
T1  - Dermal and cardiac autonomic fiber involvement in Parkinson's disease and multiple system atrophy
JF  - Neurobiology of Disease
N2  - Pathological aggregates of alpha-synuclein in peripheral dermal nerve fibers can be detected in patients with idiopathic Parkinson's disease and multiple system atrophy. This study combines skin biopsy staining for p-alpha-synuclein depositions and radionuclide imaging of the heart with [\(^{123}\)I]-metaiodobenzylguanidine to explore peripheral denervation in both diseases. To this purpose, 42 patients with a clinical diagnosis of Parkinson's disease or multiple system atrophy were enrolled. All patients underwent a standardized clinical workup including neurological evaluation, neurography, and blood samples. Skin biopsies were obtained from the distal and proximal leg, back, and neck for immunofluorescence double labeling with anti-p-alpha-synuclein and anti-PGP9.5. All patients underwent myocardial [\(^{123}\)I]-metaiodobenzylguanidine scintigraphy. Dermal p-alpha-synuclein was observed in 47.6% of Parkinson's disease patients and was mainly found in autonomic structures. 81.0% of multiple system atrophy patients had deposits with most of cases in somatosensory fibers. The [\(^{123}\)I]-metaiodobenzylguanidine heart-to-mediastinum ratio was lower in Parkinson's disease than in multiple system atrophy patients (1.94 +/- 0.63 vs. 2.91 +/- 0.96; p < 0.0001). Irrespective of the diagnosis, uptake was lower in patients with than without p-alpha-synuclein in autonomic structures (1.42 +/- 0.51 vs. 2.74 +/- 0.83; p < 0.0001). Rare cases of Parkinson's disease with p-alpha-synuclein in somatosensory fibers and multiple system atrophy patients with deposits in autonomic structures or both fiber types presented with clinically overlapping features. In conclusion, this study suggests that alpha-synuclein contributes to peripheral neurodegeneration and mediates the impairment of cardiac sympathetic neurons in patients with synucleinopathies. Furthermore, it indicates that Parkinson's disease and multiple system atrophy share pathophysiologic mechanisms of peripheral nervous system dysfunction with a clinical overlap.
KW  - peripheral nervous system
KW  - Parkinson's disease
KW  - skin biopsy
KW  - MIBG scintigraphy
KW  - multiple system atrophy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260061
VL  - 153
ER  - 
TY  - JOUR
A1  - Schumann, S.
A1  - Scherthan, H.
A1  - Pfestroff, K.
A1  - Schoof, S.
A1  - Pfestroff, A.
A1  - Hartrampf, P.
A1  - Hasenauer, N.
A1  - Buck, A. K.
A1  - Luster, M.
A1  - Port, M.
A1  - Lassmann, M.
A1  - Eberlein, U.
T1  - DNA damage and repair in peripheral blood mononuclear cells after internal ex vivo irradiation of patient blood with \(^{131}\)I
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Aim

The aim of this study was to provide a systematic approach to characterize DNA damage induction and repair in isolated peripheral blood mononuclear cells (PBMCs) after internal ex vivo irradiation with [\(^{131}\)I]NaI. In this approach, we tried to mimic ex vivo the irradiation of patient blood in the first hours after radioiodine therapy.


Material and methods

Blood of 33 patients of two centres was collected immediately before radioiodine therapy of differentiated thyroid cancer (DTC) and split into two samples. One sample served as non-irradiated control. The second sample was exposed to ionizing radiation by adding 1 ml of [\(^{131}\)I]NaI solution to 7 ml of blood, followed by incubation at 37 °C for 1 h. PBMCs of both samples were isolated, split in three parts each and (i) fixed in 70% ethanol and stored at − 20 °C directly (0 h) after irradiation, (ii) after 4 h and (iii) 24 h after irradiation and culture in RPMI medium. After immunofluorescence staining microscopically visible co-localizing γ-H2AX + 53BP1 foci were scored in 100 cells per sample as biomarkers for radiation-induced double-strand breaks (DSBs).


Results

Thirty-two of 33 blood samples could be analysed. The mean absorbed dose to the blood in all irradiated samples was 50.1 ± 2.3 mGy. For all time points (0 h, 4 h, 24 h), the average number of γ-H2AX + 53BP1 foci per cell was significantly different when compared to baseline and the other time points. The average number of radiation-induced foci (RIF) per cell after irradiation was 0.72 ± 0.16 at t = 0 h, 0.26 ± 0.09 at t = 4 h and 0.04 ± 0.09 at t = 24 h. A monoexponential fit of the mean values of the three time points provided a decay rate of 0.25 ± 0.05 h\(^{−1}\), which is in good agreement with data obtained from external irradiation with γ- or X-rays.


Conclusion

This study provides novel data about the ex vivo DSB repair in internally irradiated PBMCs of patients before radionuclide therapy. Our findings show, in a large patient sample, that efficient repair occurs after internal irradiation with 50 mGy absorbed dose, and that the induction and repair rate after \(^{131}\)I exposure is comparable to that of external irradiation with γ- or X-rays.
KW  - DNA Damage Repair
KW  - Radioiodine Therapy
KW  - γ-h2ax
KW  - 53BP1
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258863
UR  - https://link.springer.com/article/10.1007/s00259-021-05605-8
ER  - 
TY  - JOUR
A1  - Schadt, Fabian
A1  - Israel, Ina
A1  - Samnick, Samuel
T1  - Development and Validation of a Semi-Automated, Preclinical, MRI-Template Based PET Image Data Analysis Tool for Rodents
JF  - Frontiers in Neuroinformatics
N2  - AimIn PET imaging, the different types of radiotracers and accumulations, as well as the diversity of disease patterns, make the analysis of molecular imaging data acquired in vivo challenging. Here, we evaluate and validate a semi-automated MRI template-based data analysis tool that allows preclinical PET images to be aligned to a self-created PET template. Based on the user-defined volume-of-interest (VOI), image data can then be evaluated using three different semi-quantitative parameters: normalized activity, standardized uptake value, and uptake ratio.
Materials and MethodsThe nuclear medicine Data Processing Analysis tool (NU_DPA) was implemented in Matlab. Testing and validation of the tool was performed using two types of radiotracers in different kinds of stroke-related brain diseases in rat models. The radiotracers used are 2-[\(^{18}\)F]fluoro-2-deoxyglucose ([\(^{18}\)F]FDG), a metabol\(^{68}\)Ga]Ga-Fucoidan, a target-selective radioligand specifically binding to p-selectin. After manual image import, the NU_DPA tool automatically creates an averaged PET template out of the acquired PET images, to which all PET images are then aligned onto. The added MRI template-based information, resized to the lower PET resolution, defines the VOI and also allows a precise subdivision of the VOI into individual sub-regions. The aligned PET images can then be evaluated semi-quantitatively for all regions defined in the MRI atlas. In addition, a statistical analysis and evaluation of the semi-quantitative parameters can then be performed in the NU_DPA tool.
ResultsUsing ischemic stroke data in Wistar rats as an example, the statistical analysis of the tool should be demonstrated. In this [\(^{18}\)F]FDG-PET experiment, three different experimental states were compared: healthy control state, ischemic stroke without electrical stimulation, ischemic stroke with electrical stimulation. Thereby, statistical data evaluation using the NU_DPA tool showed that the glucose metabolism in a photothrombotic lesion can be influenced by electrical stimulation.
ConclusionOur NU_DPA tool allows a very flexible data evaluation of small animal PET data in vivo including statistical data evaluation. Using the radiotracers [\(^{18}\)F]FDG and [\(^{68}\)Ga]Ga-Fucoidan, it was shown that the semi-automatic MRI-template based data analysis of the NU_DPA tool is potentially suitable for both metabolic radiotracers as well as target-selective radiotracers.
KW  - data analysis
KW  - Matlab
KW  - MRI
KW  - PET
KW  - positron emission tomography
KW  - preclinical imaging
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-240289
SN  - 1662-5196
VL  - 15
ER  - 
TY  - JOUR
A1  - Lenschow, Christina
A1  - Fuss, Carmina Teresa
A1  - Kircher, Stefan
A1  - Buck, Andreas
A1  - Kickuth, Ralph
A1  - Reibetanz, Joachim
A1  - Wiegering, Armin
A1  - Stenzinger, Albrecht
A1  - Hübschmann, Daniel
A1  - Germer, Christoph Thomas
A1  - Fassnacht, Martin
A1  - Fröhling, Stefan
A1  - Schlegel, Nicolas
A1  - Kroiss, Matthias
T1  - Case Report: Abdominal Lymph Node Metastases of Parathyroid Carcinoma: Diagnostic Workup, Molecular Diagnosis, and Clinical Management
JF  - Frontiers in Endocrinology
N2  - Parathyroid carcinoma (PC) is an orphan malignancy accounting for only ~1% of all cases with primary hyperparathyroidism. The localization of recurrent PC is of critical importance and can be exceedingly difficult to diagnose and sometimes futile when common sites of recurrence in the neck and chest cannot be confirmed. Here, we present the diagnostic workup, molecular analysis and multimodal therapy of a 46-year old woman with the extraordinary manifestation of abdominal lymph node metastases 12 years after primary diagnosis of PC. The patient was referred to our endocrine tumor center in 2016 with the aim to localize the tumor causative of symptomatic biochemical recurrence. In view of the extensive previous workup we decided to perform [18F]FDG-PET-CT. A pathological lymph node in the liver hilus showed slightly increased FDG-uptake and hence was suspected as site of recurrence. Selective venous sampling confirmed increased parathyroid hormone concentration in liver veins. Abdominal lymph node metastasis was resected and histopathological examination confirmed PC. Within four months, the patient experienced biochemical recurrence and based on high tumor mutational burden detected in the surgical specimen by whole exome sequencing the patient received immunotherapy with pembrolizumab that led to a biochemical response. Subsequent to disease progression repeated abdominal lymph node resection was performed in 10/2018, 01/2019 and in 01/2020. Up to now (12/2020) the patient is biochemically free of disease. In conclusion, a multimodal diagnostic approach and therapy in an interdisciplinary setting is needed for patients with rare endocrine tumors. Molecular analyses may inform additional treatment options including checkpoint inhibitors such as pembrolizumab.
KW  - parathyroid carcinoma
KW  - abdominal lymph node metastases
KW  - molecular diagnostics
KW  - repeated surgery
KW  - [18F]FDG-PET-CT
KW  - immune check inhibitor
KW  - pembrolizumab
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233362
SN  - 1664-2392
VL  - 12
ER  - 
TY  - JOUR
A1  - Fröhlich, Matthias
A1  - Serfling, Sebastian
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Schmalzing, Marc
A1  - Tony, Hans-Peter
A1  - Gernert, Michael
A1  - Strunz, Patrick-Pascal
A1  - Portegys, Jan
A1  - Schwaneck, Eva-Christina
A1  - Gadeholt, Ottar
A1  - Weich, Alexander
A1  - Buck, Andreas K.
A1  - Bley, Thorsten A.
A1  - Guggenberger, Konstanze V.
A1  - Werner, Rudolf A.
T1  - Whole-Body [\(^{18}\)F]FDG PET/CT Can Alter Diagnosis in Patients with Suspected Rheumatic Disease
JF  - Diagnostics
N2  - The 2-deoxy-d-[\(^{18}\)F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) is widely utilized to assess the vascular and articular inflammatory burden of patients with a suspected diagnosis of rheumatic disease. We aimed to elucidate the impact of [\(^{18}\)F]FDG PET/CT on change in initially suspected diagnosis in patients at the time of the scan. Thirty-four patients, who had undergone [\(^{18}\)F]FDG PET/CT, were enrolled and the initially suspected diagnosis prior to [18F]FDG PET/CT was compared to the final diagnosis. In addition, a semi-quantitative analysis including vessel wall-to-liver (VLR) and joint-to-liver (JLR) ratios was also conducted. Prior to [\(^{18}\)F]FDG PET/CT, 22/34 (64.7%) of patients did not have an established diagnosis, whereas in 7/34 (20.6%), polymyalgia rheumatica (PMR) was suspected, and in 5/34 (14.7%), giant cell arteritis (GCA) was suspected by the referring rheumatologists. After [\(^{18}\)F]FDG PET/CT, the diagnosis was GCA in 19/34 (55.9%), combined GCA and PMR (GCA + PMR) in 9/34 (26.5%) and PMR in the remaining 6/34 (17.6%). As such, [\(^{18}\)F]FDG PET/CT altered suspected diagnosis in 28/34 (82.4%), including in all unclear cases. VLR of patients whose final diagnosis was GCA tended to be significantly higher when compared to VLR in PMR (GCA, 1.01 ± 0.08 (95%CI, 0.95–1.1) vs. PMR, 0.92 ± 0.1 (95%CI, 0.85–0.99), p = 0.07), but not when compared to PMR + GCA (1.04 ± 0.14 (95%CI, 0.95–1.13), p = 1). JLR of individuals finally diagnosed with PMR (0.94 ± 0.16, (95%CI, 0.83–1.06)), however, was significantly increased relative to JLR in GCA (0.58 ± 0.04 (95%CI, 0.55–0.61)) and GCA + PMR (0.64 ± 0.09 (95%CI, 0.57–0.71); p < 0.0001, respectively). In individuals with a suspected diagnosis of rheumatic disease, an inflammatory-directed [\(^{18}\)F]FDG PET/CT can alter diagnosis in the majority of the cases, particularly in subjects who were referred because of diagnostic uncertainty. Semi-quantitative assessment may be helpful in establishing a final diagnosis of PMR, supporting the notion that a quantitative whole-body read-out may be useful in unclear cases.
KW  - giant cell arteritis
KW  - GCA
KW  - [18F]FDG PET/CT
KW  - vasculature
KW  - inflammation
KW  - polymyalgia rheumatica
KW  - PMR
KW  - vasculitis
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250227
SN  - 2075-4418
VL  - 11
IS  - 11
ER  - 
TY  - JOUR
A1  - Lindner, Thomas
A1  - Giesel, Frederik L.
A1  - Kratochwil, Clemens
A1  - Serfling, Sebastian E.
T1  - Radioligands Targeting Fibroblast Activation Protein (FAP)
JF  - Cancers
N2  - Simple Summary
FAP-targeted radiotracers, recently introduced in cancer treatment, accumulate in Cancer-Associated Fibroblasts (CAFs). CAFs are present in tumor lesions but do not correspond to genuine cancer cells, although they behave in an abnormal and disease-promoting manner. One of their characteristic features, the expression of the surface protein FAP, can be utilized to discriminate between cancerous and healthy tissues. By the choice of an appropriate radionuclide, FAP-targeted tracers can be used for imaging or therapy in many cancer types. Therefore, the first successful application of FAP-targeted imaging has led to an enormous and growing interest in nuclear medicine and radiopharmacy.
        
        
Abstract
Targeting fibroblast activation protein (FAP) in cancer-associated fibroblasts (CAFs) has attracted significant attention in nuclear medicine. Since these cells are present in most cancerous tissues and FAP is rarely expressed in healthy tissues, anti-FAP tracers have a potential as pan-tumor agents. Compared to the standard tumor tracer [\(^{18}\)F]FDG, these tracers show better tumor-to-background ratios (TBR) in many indications. Unlike [\(^{18}\)F]FDG, FAP-targeted tracers do not require exhausting preparations, such as dietary restrictions on the part of the patient, and offer the possibility of radioligand therapy (RLT) in a theragnostic approach. Although a radiolabeled antibody was clinically investigated as early as the 1990s, the breakthrough event for FAP-targeting in nuclear medicine was the introduction and clinical application of the so-called FAPI-tracers in 2018. From then, the development and application of FAP-targeted tracers became hot topics for the radiopharmaceutical and nuclear medicine community, and attracted the interest of pharmaceutical companies. The aim of this review is to provide a comprehensive overview of the development of FAP-targeted radiopharmaceuticals and their application in nuclear medicine.
KW  - FAP
KW  - cancer associated fibroblasts
KW  - radiopharmaceuticals
KW  - drug discovery
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250121
SN  - 2072-6694
VL  - 13
IS  - 22
ER  - 
TY  - THES
A1  - Schumann, Sarah
T1  - Zeit- und Dosisabhängigkeit von DNA-Schäden induziert durch interne Bestrahlung mit unterschiedlichen Radionukliden
T1  - Time and dose dependence of DNA damage induced by internal irradiation with various radionuclides
N2  - In der Nuklearmedizin werden radioaktive Substanzen eingesetzt, um zu therapeutischen Zwecken gezielt bösartiges Gewebe zu zerstören oder in diagnostischen Anwendungen Stoffwechselvorgänge bildlich darzustellen. Die ionisierende Strahlung der eingesetzten Radionuklide kann jedoch auch DNA-Schäden in gesunden Zellen verursachen. DNA-Doppelstrangbrüche gehören dabei zu den kritischsten Läsionen, da sie schwer zu reparieren sind und eine fehlerhafte Reparatur zu Mutationen oder zum Zelltod führen kann. Während Radionuklidtherapien ist daher in Risikoorganen darauf zu achten, dass die deponierte Energie pro Masse, die Energiedosis, bestimmte Werte nicht überschreitet. Zu diesen Risikoorganen gehört auch das blutbildende System. Da eine Abschätzung der Energiedosis im Knochenmark häufig über die Bestimmung der Energiedosis im Blut als Surrogat erfolgt, ist deren Kenntnis von besonderem Interesse.
In dieser Arbeit wurden daher Berechnungen der Energiedosis im Blut nach interner Bestrahlung durchgeführt und die Ergebnisse mit der Anzahl an strahlungsinduzierten DNA-Doppelstrangbrüchen in PBMCs korreliert. Zur Quantifizierung der DNA-Schäden wurden die Biomarker \(\gamma\)-H2AX und 53BP1 verwendet, die nach Entstehung eines Doppelstrangbruchs um diesen akkumulieren und sich durch Immunfluoreszenzfärbung als mikroskopische Foci sichtbar machen und quantifizieren lassen. Dadurch ermöglicht der \(\gamma\)-H2AX+53BP1-Assay einen quantitativen Nachweis strahlungsinduzierter Doppelstrangbrüche. Somit konnten im Rahmen dieser Arbeit neue Kenntnisse über die Dosisabhängigkeit von DNA-Schäden in PBMCs während interner Bestrahlung mit unterschiedlichen Radionukliden sowohl ex vivo als auch in vivo gewonnen werden.
Ex-vivo-Untersuchungen haben den Vorteil, dass sie unter gleichbleibenden, gut definierten Bedingungen durchgeführt werden können und somit eine Analyse der Induktion von Doppelstrangbrüchen bei festgelegten Energiedosen und einer konstanten Bestrahlungsdauer erlauben. In dieser Arbeit wurden Blutproben von gesunden Versuchspersonen durch Zugabe von Radionukliden in bestimmten Aktivitätskonzentrationen eine Stunde lang intern bestrahlt. Für die Bestrahlung wurden die \(\alpha\)-Emitter \(^{223}\)Ra und \(^{224}\)Ra, die \(\beta\)\(^{-}\)-Emitter \(^{177}\)Lu und \(^{90}\)Y, der \(\beta\)\(^{+}\)-Emitter \(^{68}\)Ga und der \(\gamma\)-Emitter \(^{99m}\)Tc verwendet. Der untersuchte Energiedosisbereich lag zwischen 5 mGy und 136 mGy.
Nach der Bestrahlung von Blutproben mit \(\beta\)- beziehungsweise \(\gamma\)-Emittern wurde beobachtet, dass die Anzahl der strahlungsinduzierten \(\gamma\)-H2AX+53BP1-Foci (RIF) in den PBMCs linear mit der Energiedosis im Blut ansteigt. Zudem zeigte sich, dass die Induktion der RIF unabhängig vom verwendeten Radionuklid und unabhängig von der Versuchsperson ist.
Nach der Bestrahlung von Blutproben mit \(\alpha\)-Emittern waren zusätzlich zu den nach Expositionen mit \(\beta\)- beziehungsweise \(\gamma\)-Emittern beobachteten kleinen, runden Foci auch \(\gamma\)-H2AX+53BP1 enthaltende Spuren \(\alpha\)-Spuren) in den Zellkernen erkennbar, welche die Trajektorien der emittierten \(\alpha\)-Teilchen darstellten. Es konnte gezeigt werden, dass die Anzahl dieser \(\alpha\)-Spuren linear mit der Energiedosis im Blut zunimmt und damit ein geeigneter Parameter für die Biodosimetrie nach Expositionen mit \(\alpha\)-emittierenden Radionukliden ist.
Auch in vivo wurde die Dosisabhängigkeit der DNA-Doppelstrangbrüche während der internen Bestrahlung durch Radionuklide mit unterschiedlichen Emissionseigenschaften untersucht. Aufgrund der neuen, vielversprechenden Entwicklungen von Radiopharmaka zur Therapie und Diagnostik des Prostatakarzinoms in den letzten Jahren wurden dafür Blutproben von Prostatakarzinom-Patienten während Therapie mit [\(^{177}\)Lu]Lu-PSMA I&T, während PET/CT-Diagnostik mit [\(^{68}\)Ga]Ga-PSMA I&T und während Therapie mit [\(^{223}\)Ra]RaCl\(_2\) untersucht.
Während Therapie mit [\(^{177}\)Lu]Lu-PSMA I&T zeigte sich, dass die Anzahl der RIF in den ersten Stunden nach Therapiebeginn durch eine lineare Anpassungskurve angenähert werden kann, die mit der Energiedosis im Blut ansteigt, gefolgt von einem Rückgang der RIF zu späteren Zeitpunkten, der durch die DNA-Reparatur erklärt werden kann. Die gesamte Energiedosis im Blut lag im Mittel bei (109 \(\pm\) 28) mGy. Der linear dosisabhängige Anstieg der RIF zu Therapiebeginn gleicht der dosisabhängigen Induktion der RIF ex vivo nach Bestrahlung mit \(\beta\)- und \(\gamma\)-emittierenden Radionukliden und kann gut mit der entsprechenden Ex-vivo-Kalibrierkurve beschrieben werden. Zu späteren Zeitpunkten (48 h und 96 h nach Verabreichung) konnte in dieser Arbeit eine lineare Korrelation zwischen der Anzahl der noch verbleibenden RIF und der Dosisleistung nachgewiesen werden. Eine signifikante Korrelation der Anzahl der RIF 96 h nach Verabreichung mit dem PSA-Wert deutet zudem darauf hin, dass ein Zusammenhang mit klinischen Parametern besteht.
Ein signifikanter Anstieg der \(\gamma\)-H2AX+53BP1-Foci konnte auch nach Verabreichung von [\(^{68}\)Ga]Ga-PSMA I&T für diagnostische PET/CT-Untersuchungen beobachtet werden, obwohl die Energiedosen im Blut bis zum PET/CT-Scan nur < 3 mGy betrugen. Im Vergleich zur Ex-vivo-Kalibrierkurve war die Steigung der linearen Anpassungskurve in vivo im Bereich < 3 mGy in dieser Studie etwa um ein Zehnfaches höher, was auf eine mögliche Hypersensitivität im Niedrigdosisbereich hindeuten könnte. Der Beitrag der CT zur Energiedosis im Blut konnte durch Ex-vivo-Experimente auf etwa 12 mGy abgeschätzt werden.
Auch während Therapie mit [\(^{223}\)Ra]RaCl\(_2\) lagen die berechneten Energiedosen im Blut im Niedrigdosisbereich < 17 mGy. Trotzdem konnten in dieser Studie erstmalig \(\alpha\)-Spuren in vivo nach der Verabreichung eines \(\alpha\)-emittierenden Radionuklids quantifiziert werden, deren Anzahl 3 h und 4 h nach Verabreichung des Radiopharmakons signifikant erhöht war. Auch zu späten Zeitpunkten, bis vier Wochen nach Therapiebeginn, waren noch \(\alpha\)-Spuren nachweisbar, was auf eine unvollständige Reparatur der komplexen, durch die \(\alpha\)-Teilchen induzierten DNA-Schäden hinweisen könnte. Leider erlaubte die geringe Anzahl an Patienten und Datenpunkten keine zuverlässigen Korrelationen mit der Energiedosis oder mit klinischen Parametern.
Nachdem in dieser Arbeit gezeigt werden konnte, dass DNA-Schäden nach interner Bestrahlung mit \(\alpha\)-, \(\beta\)- und \(\gamma\)-emittierenden Radionukliden mit Hilfe des \(\gamma\)-H2AX+53BP1-Assays zuverlässig nachgewiesen und anhand der Schadensgeometrie unterschieden werden können, wäre es in Zukunft interessant, DNA-Schäden auch nach Bestrahlung mit Radionuklidgemischen zu untersuchen. Dies könnte sowohl im Hinblick auf den Nachweis von Inkorporationen bei Strahlenunfällen hilfreich sein als auch zu einem besseren Verständnis der Effekte bei Behandlungen mit Radionuklidgemischen beitragen, welche vielversprechende Möglichkeiten für nuklearmedizinische Therapien bieten. 
Zudem zeigen die Ergebnisse dieser Arbeit, dass insbesondere im für die Diagnostik relevanten Bereich sehr niedriger Energiedosen < 10 mGy weiterer Forschungsbedarf besteht. Durch die Untersuchung der dosisabhängigen Reparatur der durch interne Bestrahlung induzierten DNA-Schäden könnte beispielsweise analysiert werden, ob die Reparaturfähigkeit im Niedrigdosisbereich eingeschränkt ist. Außerdem wäre es gerade im Bereich niedriger Dosen von Interesse, zu untersuchen, inwiefern Beobachtungen ex vivo das Verhalten in vivo geeignet repräsentieren. Um die erhöhten statistischen Unsicherheiten im Niedrigdosisbereich zu reduzieren, könnten zukünftig Verbesserungen auf dem Gebiet der automatisierten Auswertung der \(\gamma\)-H2AX+53BP1 enthaltenden Foci und Spuren hilfreich sein.
Weitere Ziele zukünftiger Forschungsvorhaben könnten gezielte Untersuchungen zu Korrelationen zwischen der dosisabhängigen Induktion und Reparatur von DNA-Schäden und klinischen Parametern sowie die Analyse von DNA-Schäden während mehrerer Therapiezyklen darstellen. In Zusammenhang mit der Analyse klinischer Parameter wäre es denkbar, dass biodosimetrische Auswertungen zukünftig auch zur personalisierten Therapieplanung oder auch zur Vorhersage des Therapieerfolgs dienen und somit langfristig zu einer Optimierung nuklearmedizinischer Therapien beitragen könnten.
N2  - In nuclear medicine, radioactive substances are applied for therapeutic purposes to destroy malignant tissue, or in diagnostic applications to visualize metabolic processes. However, the ionizing radiation of the applied radionuclides can also cause DNA damage in healthy cells. Among these, DNA double-strand breaks belong to the most critical lesions because they are difficult to repair and misrepair can lead to mutations or cell death. Therefore, during radionuclide therapies, it is of great importance to ensure that the deposited energy per mass, the absorbed dose, does not exceed certain values in organs at risk. One of these organs at risk is the hematopoietic system. As the absorbed dose to the bone marrow is often estimated by determining the absorbed dose to the blood as a surrogate, knowledge of the latter is of particular interest. 
Therefore, in this thesis, calculations of the absorbed dose to the blood after internal irradiation were performed and the results were correlated with the number of radiation-induced DNA double-strand breaks in PBMCs. To quantify DNA damage, the biomarkers \(\gamma\)-H2AX and 53BP1 were used, which accumulate around a double-strand break after its formation and which can be visualized and quantified as microscopic foci by immunofluorescence staining. Consequently, the \(\gamma\)-H2AX+53BP1 assay allows a quantitative detection of radiation-induced double-strand breaks. Thus, by combining absorbed dose calculations with a quantitative analysis of DNA damage in PBMCs during internal irradiation with various radionuclides both ex vivo and in vivo, new knowledge was gained in the context of this work.
Ex-vivo examinations have the advantage that they can be carried out under constant, well-defined conditions and thus allow an analysis of the induction of double-strand breaks at preset absorbed doses and a constant irradiation duration. In this work, blood samples from healthy test persons were internally irradiated for one hour by adding radionuclides at defined activity concentrations. For the irradiation, the \(\alpha\)-emitters \(^{223}\)Ra and \(^{224}\)Ra, the \(\beta\)\(^{-}\)-emitters \(^{177}\)Lu and \(^{90}\)Y, the \(\beta\)\(^{+}\)-emitter \(^{68}\)Ga and the \(\gamma\)-emitter \(^{99m}\)Tc were used. The absorbed dose ranged from 5 mGy to 136 mGy.
After irradiating blood samples with \(\beta\)- and \(\gamma\)-emitters, it was observed that the number of radiation-induced \(\gamma\)-H2AX+53BP1 foci (RIF) in the PBMCs increases linearly with the absorbed dose to the blood. Furthermore, it was shown that the induction of RIF is independent of the radionuclide applied and the test person.
After irradiating blood samples with \(\alpha\)-emitters, in addition to the small round foci observed after exposure to \(\beta\)- and \(\gamma\)-emitters, \(\gamma\)-H2AX+53BP1 containing tracks (\(\alpha\)-tracks) were visible in the nuclei, which represented the trajectories of the emitted \(\alpha\)-particles. It was shown that the number of these \(\alpha\)-tracks increases linearly with the absorbed dose to the blood and is, therefore, a suitable parameter for biodosimetry after exposure to \(\alpha\)-emitting radionuclides.
The absorbed dose dependence of DNA double-strand breaks during internal irradiation with radionuclides with different emission properties was also investigated in vivo. Due to the promising new developments of radiopharmaceuticals for therapy and diagnostics of prostate cancer in recent years, blood samples from prostate cancer patients were examined during therapy with [\(^{177}\)Lu]Lu-PSMA I&T, during PET/CT diagnostics with [\(^{68}\)Ga]Ga-PSMA I&T and during therapy with [\(^{223}\)Ra]RaCl\(_2\).

During therapy with [\(^{177}\)Lu]Lu-PSMA I&T, it was shown that the number of RIF in the first hours after therapy start can be approximated by a linear fitting curve, which increases with the absorbed dose to the blood, followed by a decrease in RIF at later time points, which can be explained by DNA repair. The total absorbed dose to the blood was (109 \(\pm\) 28) mGy on average.
The linear absorbed dose-dependent increase in RIF at the beginning of therapy is similar to the absorbed dose-dependent induction of RIF ex vivo after irradiation with \(\beta\)- and \(\gamma\)-emitting radionuclides and can be well described with the corresponding ex-vivo calibration curve. At later time points (48 h and 96 h after administration), a linear correlation between the number of remaining RIF and the dose rate was demonstrated in this work. A significant correlation of the number of RIF 96 h after administration with PSA levels also suggests a link to clinical parameters.
A significant increase in \(\gamma\)-H2AX+53BP1 foci was also observed after administration of [\(^{68}\)Ga]Ga-PSMA I&T for diagnostic PET/CT examinations, despite the fact that absorbed doses to the blood were only < 3 mGy by the time of the PET/CT scan. Compared to the ex-vivo calibration curve, the slope of the linear in-vivo fitting curve in the range < 3 mGy in this study was approximately ten times higher, which may indicate a possible hypersensitivity in the low dose range. The contribution of the CT to the absorbed dose to the blood was estimated at approximately 12 mGy by ex-vivo experiments.
During therapy with [\(^{223}\)Ra]RaCl\(_2\), the calculated absorbed doses to the blood were also in the low dose range < 17 mGy. Nevertheless, this study was the first to quantify \(\alpha\)-tracks in vivo after the administration of an \(\alpha\)-emitting radionuclide, with a significantly increased number of \(\alpha\)-tracks 3 h and 4 h after administration of the radiopharmaceutical. Even at late time points, up to four weeks after therapy start, \(\alpha\)-tracks were still detectable, which could indicate incomplete repair of the complex DNA damage induced by \(\alpha\)-particles. Unfortunately, the small number of patients and data points did not allow reliable correlations with the absorbed dose or clinical parameters.
In this thesis, it was shown that DNA damage after internal irradiation with \(\alpha\)-, \(\beta\)- and \(\gamma\)-emitting radionuclides can be reliably detected by applying the \(\gamma\)-H2AX+53BP1 assay and distinguished by damage geometry. For future work, it would be of interest to additionally investigate DNA damage after irradiation with mixtures of radionuclides. This could be helpful for the detection of incorporations after radiation accidents, and could also contribute to a better understanding of the effects of therapeutic applications of radionuclide mixtures, which offer promising opportunities for nuclear medicine therapies.
Furthermore, the results of this work show that there is need for further research, especially in the very low dose range < 10 mGy, which is relevant for diagnostics. By investigating the absorbed dose-dependent repair of DNA damage induced by internal irradiation, for example, it could be analyzed whether the repair capability is limited in the low dose range. Particularly in the range of low doses, it would also be of interest to investigate to what extent observations ex vivo adequately represent the behavior in vivo. In order to reduce the increased statistical uncertainties in the low dose range, future improvements in the field of automated evaluation of \(\gamma\)-H2AX+53BP1 containing foci and tracks could be helpful.
Further objectives of future research projects could be investigations focussing on correlations between the absorbed dose-dependent induction and repair of DNA damage and clinical parameters as well as an analysis of DNA damage over several therapy cycles. In the context of the analysis of clinical parameters, it is conceivable that biodosimetric assessments could enhance personalized treatment planning or the prediction of therapy success, thus contributing, in the long-term, to an optimization of nuclear medicine therapies.
KW  - Nuklearmedizin
KW  - Dosimetrie
KW  - Radionuklid
KW  - DNS-Doppelstrangbruch
KW  - Biomarker
KW  - Medizinphysik
KW  - gamma-H2AX
KW  - 53BP1
KW  - nuclear medicine
KW  - dosimetry
KW  - radionuclide
KW  - DNA damage
KW  - medical physics
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-223904
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Lapa, Constantin
A1  - Serfling, Sebastian E.
A1  - Buck, Andreas K.
A1  - Seitz, Anna Katharina
A1  - Meyer, Philipp T.
A1  - Ruf, Juri
A1  - Michalski, Kerstin
T1  - Development of Discordant Hypermetabolic Prostate Cancer Lesions in the Course of [\(^{177}\)Lu]PSMA Radioligand Therapy and Their Possible Influence on Patient Outcome
JF  - Cancers
N2  - Simple Summary
Discordant FDG-positive but PSMA-negative (FDG+/PSMA−) metastases constitute a negative prognostic marker of overall survival in patients undergoing PSMA radioligand therapy (RLT). The aim of this analysis was to investigate the prognostic implications of new FDG+/PSMA− lesions, which occur during or after PSMA RLT. In a retrospective bicentric analysis of 32 patients undergoing PSMA RLT and follow-up dual tracer staging with PSMA and FDG PET/CT, FDG+/PSMA− lesions occurred in a limited number of patients. However, the presence of FDG+/PSMA− lesions appears not to have a significant impact on the OS, but further studies are needed to establish the clinical relevance of such lesions.

Abstract
Introduction: Positron emission tomography/computer tomography (PET/CT) targeting the prostate-specific membrane antigen (PSMA) is crucial for the assessment of adequate PSMA expression in patients with metastatic castration-resistant prostate cancer (mCRPC) prior to PSMA radioligand therapy (PSMA RLT). Moreover, initial dual tracer staging using combined PSMA and [\(^{18}\)F]fluorodeoxyglucose (FDG) PET/CT provides relevant information, since discordant FDG-positive but PSMA-negative (FDG+/PSMA−) lesions constitute a negative prognostic marker of overall survival (OS) after PSMA RLT. However, little is known about the prognostic implications of dual tracer imaging for restaging at follow-up. The aim of this analysis was to investigate the prognostic implications of new FDG+/PSMA− lesions during or after PSMA RLT. Methods: This bicentric analysis included 32 patients with mCRPC who underwent both FDG and PSMA PET/CT imaging after two or four cycles of PSMA RLT. Patients with FDG+/PSMA− lesions prior to PSMA RLT were not considered. The presence of FDG+/PSMA− lesions was assessed with follow-up dual tracer imaging of patients after two or four cycles of PSMA RLT. Patients with at least one new FDG+/PSMA− lesion were compared to patients without any FDG+/PSMA− lesions at the respective time points. A log-rank analysis was used to assess the difference in OS between subgroups. Results: After two cycles of PSMA RLT, four of 32 patients (13%) had FDG+/PSMA− metastases. No significant difference in OS was observed (p = 0.807), as compared to patients without FDG+/PSMA− lesions. Follow-up dual tracer imaging after the 4th cycle of PSMA RLT was available in 18 patients. Of these, four patients presented with FDG+/PSMA− findings (n = 2 already after two cycles). After the fourth cycle of PSMA RLT, no significant difference in OS was observed between patients with and without FDG+/PSMA− lesions (p = 0.442). Conclusion: This study shows that FDG+/PSMA− lesions develop in a limited number of patients undergoing PSMA RLT. Further studies are needed to establish the clinical relevance of such lesions.
KW  - PSMA
KW  - FDG
KW  - PET/CT
KW  - prostate cancer
KW  - radioligand therapy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-245168
SN  - 2072-6694
VL  - 13
IS  - 17
ER  - 
TY  - JOUR
A1  - Detomas, Mario
A1  - Altieri, Barbara
A1  - Schlötelburg, Wiebke
A1  - Appenzeller, Silke
A1  - Schlaffer, Sven
A1  - Coras, Roland
A1  - Schirbel, Andreas
A1  - Wild, Vanessa
A1  - Kroiss, Matthias
A1  - Sbiera, Silviu
A1  - Fassnacht, Martin
A1  - Deutschbein, Timo
T1  - Case Report: Consecutive Adrenal Cushing’s Syndrome and Cushing’s Disease in a Patient With Somatic CTNNB1, USP8, and NR3C1 Mutations
JF  - Frontiers in Endocrinology
N2  - The occurrence of different subtypes of endogenous Cushing’s syndrome (CS) in single individuals is extremely rare. We here present the case of a female patient who was successfully cured from adrenal CS 4 years before being diagnosed with Cushing’s disease (CD). The patient was diagnosed at the age of 50 with ACTH-independent CS and a left-sided adrenal adenoma, in January 2015. After adrenalectomy and histopathological confirmation of a cortisol-producing adrenocortical adenoma, biochemical hypercortisolism and clinical symptoms significantly improved. However, starting from 2018, the patient again developed signs and symptoms of recurrent CS. Subsequent biochemical and radiological workup suggested the presence of ACTH-dependent CS along with a pituitary microadenoma. The patient underwent successful transsphenoidal adenomectomy, and both postoperative adrenal insufficiency and histopathological workup confirmed the diagnosis of CD. Exome sequencing excluded a causative germline mutation but showed somatic mutations of the β-catenin protein gene (CTNNB1) in the adrenal adenoma, and of both the ubiquitin specific peptidase 8 (USP8) and the glucocorticoid receptor (NR3C1) genes in the pituitary adenoma. In conclusion, our case illustrates that both ACTH-independent and ACTH-dependent CS may develop in a single individual even without evidence for a common genetic background.
KW  - Cushing’s syndrome
KW  - Cushing’s disease
KW  - hypercortisolism
KW  - glucocorticoid excess
KW  - USP8
KW  - CTNNB1
KW  - NR3C1
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-244596
SN  - 1664-2392
VL  - 12
ER  - 
TY  - JOUR
A1  - Gentzsch, Christian
A1  - Hoffmann, Matthias
A1  - Ohshima, Yasuhiro
A1  - Nose, Naoko
A1  - Chen, Xinyu
A1  - Higuchi, Takahiro
A1  - Decker, Michael
T1  - Synthesis and Initial Characterization of a Selective, Pseudo‐irreversible Inhibitor of Human Butyrylcholinesterase as PET Tracer
JF  - ChemMedChem
N2  - The enzyme butyrylcholinesterase (BChE) represents a promising target for imaging probes to potentially enable early diagnosis of neurodegenerative diseases like Alzheimer's disease (AD) and to monitor disease progression in some forms of cancer. In this study, we present the design, facile synthesis, in vitro and preliminary ex vivo and in vivo evaluation of a morpholine‐based, selective inhibitor of human BChE as a positron emission tomography (PET) tracer with a pseudo‐irreversible binding mode. We demonstrate a novel protecting group strategy for 18F radiolabeling of carbamate precursors and show that the inhibitory potency as well as kinetic properties of our unlabeled reference compound were retained in comparison to the parent compound. In particular, the prolonged duration of enzyme inhibition of such a morpholinocarbamate motivated us to design a PET tracer, possibly enabling a precise mapping of BChE distribution.
KW  - carbamate
KW  - enzyme kinetics
KW  - fluorine-18
KW  - positron emission tomography
KW  - radiotracers
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239904
VL  - 16
IS  - 9
SP  - 1427
EP  - 1437
ER  - 
TY  - JOUR
A1  - Weich, Alexander
A1  - Werner, Rudolf A.
A1  - Buck, Andreas K.
A1  - Hartrampf, Philipp E.
A1  - Serfling, Sebastian E.
A1  - Scheurlen, Michael
A1  - Wester, Hans-Jürgen
A1  - Meining, Alexander
A1  - Kircher, Stefan
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Kircher, Malte
T1  - CXCR4-Directed PET/CT in Patients with Newly Diagnosed Neuroendocrine Carcinomas
JF  - Diagnostics
N2  - We aimed to elucidate the diagnostic potential of the C-X-C motif chemokine receptor 4 (CXCR4)-directed positron emission tomography (PET) tracer \(^{68}\)Ga-Pentixafor in patients with poorly differentiated neuroendocrine carcinomas (NEC), relative to the established reference standard \(^{18}\)F-FDG PET/computed tomography (CT). In our database, we retrospectively identified 11 treatment-naïve patients with histologically proven NEC, who underwent \(^{18}\)F-FDG and CXCR4-directed PET/CT for staging and therapy planning. The images were analyzed on a per-patient and per-lesion basis and compared to immunohistochemical staining (IHC) of CXCR4 from PET-guided biopsies. \(^{68}\)Ga-Pentixafor visualized tumor lesions in 10/11 subjects, while \(^{18}\)F-FDG revealed sites of disease in all 11 patients. Although weak to moderate CXCR4 expression could be corroborated by IHC in 10/11 cases, \(^{18}\)F-FDG PET/CT detected significantly more tumor lesions (102 vs. 42; total lesions, n = 107; p < 0.001). Semi-quantitative analysis revealed markedly higher 18F-FDG uptake as compared to \(^{68}\)Ga-Pentixafor (maximum and mean standardized uptake values (SUV) and tumor-to-background ratios (TBR) of cancerous lesions, SUVmax: 12.8 ± 9.8 vs. 5.2 ± 3.7; SUVmean: 7.4 ± 5.4 vs. 3.1 ± 3.2, p < 0.001; and, TBR 7.2 ± 7.9 vs. 3.4 ± 3.0, p < 0.001). Non-invasive imaging of CXCR4 expression in NEC is inferior to the reference standard \(^{18}\)F-FDG PET/CT.
KW  - CXCR4
KW  - NET
KW  - NEC
KW  - <sup>68</sup>Ga-Pentixafor
KW  - <sup>18</sup>F-FDG
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234231
SN  - 2075-4418
VL  - 11
IS  - 4
ER  - 
TY  - THES
A1  - Kaiser, Franz R.
T1  - Ein \(^{18}\)F markiertes PET-Radiopharmakon (LMI1195) zur Bildgebung des Norepinephrin-Stoffwechsels im Rattenherz
T1  - An \(^{18}\)-F labeled PET radiopharmaceutical (LMI1195) for imaging of the norepinephrine metabolism in the rat heart
N2  - Der neuartige (18)F-markierte Tracer, LMI1195 (N-[3-bromo-4-(3-(18)F-fluoro-propoxy)-benzyl]-guanidine) wurde für die Bildgebung des sympathischen Nervensystems entwickelt; die hohe Spezifität dieses Tracers für den neuralen Uptake-1 Mechanismus wurde bereits gezeigt in Zell-Versuchen, sowie in Studien mit Kaninchen- und nicht menschlichen Primaten zur Bestimmung des kardialen Tracer-Uptakes. Das Ziel dieser Studie war es, die Mechanismen des kardialen (18)F-LMI1195-Uptakes in der Ratte zu untersuchen, von der bekannt ist, dass es neben dem Uptake-1 Mechanismus weitere Arten der Noradrenalin-Aufnahme im Herzen gibt.
N2  - The novel PET Tracer N-[3-bromo-4-(3-18F-fluoropropoxy)-benzyl]-guanidin (LMI1195) has recently been developed for the imaging of the sympathetic nervous system. Previous studies in cell models, as well as rabbit and nonhuman primate studies have shown a high specificity for the cardiac neural uptake-1 mechanism. The aim of this study was to further assess the mechanisms of the cardiac 18-F-LMI1195 uptake in the rat heart, known to have additional, differing norepinephrine uptake mechanisms besides neural uptake-1.
KW  - LMI1195
KW  - Uptake-1
KW  - Ratte
KW  - LMI1195
KW  - Uptake-1
KW  - Ratte
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-244335
ER  - 
TY  - JOUR
A1  - Richter, Julian A. J.
A1  - Wech, Tobias
A1  - Weng, Andreas M.
A1  - Stich, Manuel
A1  - Weick, Stefan
A1  - Breuer, Kathrin
A1  - Bley, Thorsten A.
A1  - Köstler, Herbert
T1  - Free‐breathing self‐gated 4D lung MRI using wave‐CAIPI
JF  - Magnetic Resonance in Medicine
N2  - Purpose
The aim of this study was to compare the wave‐CAIPI (controlled aliasing in parallel imaging) trajectory to the Cartesian sampling for accelerated free‐breathing 4D lung MRI.

Methods
The wave‐CAIPI k‐space trajectory was implemented in a respiratory self‐gated 3D spoiled gradient echo pulse sequence. Trajectory correction applying the gradient system transfer function was used, and images were reconstructed using an iterative conjugate gradient SENSE (CG SENSE) algorithm. Five healthy volunteers and one patient with squamous cell carcinoma in the lung were examined on a clinical 3T scanner, using both sampling schemes. For quantitative comparison of wave‐CAIPI and standard Cartesian imaging, the normalized mutual information and the RMS error between retrospectively accelerated acquisitions and their respective references were calculated. The SNR ratios were investigated in a phantom study.

Results
The obtained normalized mutual information values indicate a lower information loss due to acceleration for the wave‐CAIPI approach. Average normalized mutual information values of the wave‐CAIPI acquisitions were 10% higher, compared with Cartesian sampling. Furthermore, the RMS error of the wave‐CAIPI technique was lower by 19% and the SNR was higher by 14%. Especially for short acquisition times (down to 1 minute), the undersampled Cartesian images showed an increased artifact level, compared with wave‐CAIPI.

Conclusion
The application of the wave‐CAIPI technique to 4D lung MRI reduces undersampling artifacts, in comparison to a Cartesian acquisition of the same scan time. The benefit of wave‐CAIPI sampling can therefore be traded for shorter examinations, or enhancing image quality of undersampled 4D lung acquisitions, keeping the scan time constant.
KW  - free‐breathing
KW  - lung
KW  - self‐gated
KW  - wave‐CAIPI
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218075
VL  - 84
IS  - 6
SP  - 3223
EP  - 3233
ER  - 
TY  - THES
A1  - Bögelein, Anna
T1  - Einfluss systemischer Therapeutika auf die CXCR4-Expression von Myelomzellen
T1  - Influence of therapeutic agents on CXCR4 expression of myeloma cells
N2  - Im Zuge der Bemühungen um neue, tumorspezifische Therapieansätze für die Myelomerkrankung hat sich der C-X-C-Chemokinrezeptor 4 (CXCR4) aufgrund seiner zentralen Rolle in der Tumorgenese als vielversprechender Angriffspunkt hervorgetan. Im Sinne eines theranostischen Konzepts wird der Rezeptor mithilfe eines radioaktiv markierten Liganden quantifiziert und anschließend von rezeptorspezifischen Radiotherapeutika als Zielstruktur genutzt. Die CXCR4-Expression ist allerdings ein höchst dynamischer Prozess mit großer inter- und intraindividueller Heterogenität, der u.a. durch eine begleitende Chemotherapie beeinflusst werden kann. Ob sich therapieinduzierte Veränderungen der Rezeptorexpression gezielt nutzen lassen, um die CXCR4-Expression zu optimieren und so die Effektivität der CXCR4-gerichteten Strategien zu steigern, wurde bislang nicht untersucht.
Vor diesem Hintergrund wurden in der vorliegenden Arbeit verschiedene, in der Myelomtherapie etablierte Substanzen sowohl einzeln als auch in Kombination hinsichtlich ihres Einflusses auf die CXCR4-Expression von MM-Zelllinien und primären MM-Zellen unter in vitro Bedingungen analysiert.
In den durchgeführten Experimenten zeigte sich eine hohe Variabilität der CXCR4-Expression der MM-Zellen nach Therapieinduktion, die sich als substanz-, dosis- und zeitabhängig herausstellte. Die Ergebnisse bestätigten das große Potenzial der therapieinduzierten Modulation der CXCR4-Expression. Im weiteren Verlauf sind translationale Forschungsansätze gerechtfertigt, die die Übertragbarkeit der in vitro gewonnenen Ergebnisse auf die komplexen Vorgänge im lebenden Organismus überprüfen. Langfristiges Ziel ist der Entwurf eines patientenzentrierten, multimodalen Therapiekonzepts, welches das CXCR4-gerichtete theranostische Konzept mit einer individuell angepassten, medikamentösen MM-Therapie kombiniert.
N2  - In the course of developing new tumor specific therapeutic approaches for non-yet curable myeloma disease C-X-C chemokine receptor 4 (CXCR4) has emerged as a promising target due to its crucial role in myeloma tumorigenesis. Within a theranostic concept CXCR4 is quantified using radioactively labeled ligands and afterwards targeted by receptor-specific radiopharmaceuticals. However, CXCR4 expression is a very dynamic process with a high inter- and intraindividual heterogeneity which can be influenced by concomitant chemotherapy. Whether therapy induced changes in receptor expression can be used to enhance CXCR4 expression and thus to improve efficacy of CXCR4-based theranostics has not been examined so far.
In this context the present study evaluated the effect of several anti-myeloma drugs (bortezomib, cyclophosphamide, dexamethasone, doxorubicin, lenalidomide) on CXCR4 expression of different human myeloma cell lines as well as patient-derived CD138+ plasma cells under in vitro conditions.
Findings disclosed a high variability of CXCR4 expression on myeloma cells after drug application which turned out to be substance-, dose- and time-dependent. The results confirmed the high potential of therapy-induced modulation of CXCR4 expression. In further course, translational research approaches are justified to verify the transferability of the in vitro findings to the complex macro- and microenvironment in vivo. Long-term goal is the development of a patient-centered, multimodal therapy concept which combines CXCR4 based theranostics with a personalized drug-based therapy.
KW  - Plasmozytom
KW  - In vitro
KW  - Multiples Myelom
KW  - Theranostik
KW  - CXCR4
KW  - Gallium-68 Pentixafor
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241746
ER  - 
TY  - JOUR
A1  - Chen, Xinyu
A1  - Kudo, Takashi
A1  - Lapa, Constantin
A1  - Buck, Andreas
A1  - Higuchi, Takahiro
T1  - Recent advances in radiotracers targeting norepinephrine transporter: structural development and radiolabeling improvements
JF  - Journal of Neural Transmission
N2  - The norepinephrine transporter (NET) is a major target for the evaluation of the cardiac sympathetic nerve system in patients with heart failure and Parkinson's disease. It is also used in the therapeutic applications against certain types of neuroendocrine tumors, as exemplified by the clinically used \(^{123/131}\)I-MIBG as theranostic single-photon emission computed tomography (SPECT) agent. With the development of more advanced positron emission tomography (PET) technology, more radiotracers targeting NET have been reported, with superior temporal and spatial resolutions, along with the possibility of functional and kinetic analysis. More recently, fluorine-18-labelled NET tracers have drawn increasing attentions from researchers, due to their longer radiological half-life relative to carbon-11 (110 min vs. 20 min), reduced dependence on on-site cyclotrons, and flexibility in the design of novel tracer structures. In the heart, certain NET tracers provide integral diagnostic information on sympathetic innervation and the nerve status. In the central nervous system, such radiotracers can reveal NET distribution and density in pathological conditions. Most radiotracers targeting cardiac NET-function for the cardiac application consistent of derivatives of either norepinephrine or MIBG with its benzylguanidine core structure, e.g. \(^{11}\)C-HED and \(^{18}\)F-LMI1195. In contrast, all NET tracers used in central nervous system applications are derived from clinically used antidepressants. Lastly, possible applications of NET as selective tracers over organic cation transporters (OCTs) in the kidneys and other organs controlled by sympathetic nervous system will also be discussed.
KW  - norepinephrine transporter
KW  - benzylguanidine
KW  - phenethylguanidine
KW  - antidepressant
KW  - organic cation transporter
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241148
VL  - 127
ER  - 
TY  - JOUR
A1  - Reiners, Christoph
A1  - Drozd, Valentina
A1  - Yamashita, Shunichi
T1  - Hypothyroidism after radiation exposure: brief narrative review
JF  - Journal of Neural Transmission
N2  - The thyroid gland is among the organs at the greatest risk of cancer from ionizing radiation. Epidemiological evidence from survivors of radiation therapy, atomic bombing, and the Chernobyl reactor accident, clearly shows that radiation exposure in childhood can cause thyroid cancer and benign thyroid nodules. Radiation exposure also may induce hypothyroidism and autoimmune reactions against the thyroid, but these effects are less well-documented. The literature includes only a few, methodologically weak animal studies regarding genetic/molecular mechanisms underlying hypothyroidism and thyroid autoimmunity after radiation exposure. Rather, evidence about radiation-induced hypothyroidism and thyroid autoimmunity derives mainly from follow-up studies in patients treated with external beam radiotherapy (EBRT) or iodine-131, and from epidemiological studies in the atomic bombing or nuclear accident survivors. Historically, hypothyroidism after external irradiation of the thyroid in adulthood was considered not to develop below a 10–20 Gy dose threshold. Newer data suggest a 10 Gy threshold after EBRT. By contrast, data from patients after iodine-131 “internal radiation therapy” of Graves´ disease indicate that hypothyroidism rarely occurs below thyroid doses of 50 Gy. Studies in children affected by the Chernobyl accident indicate that the dose threshold for hypothyroidism may be considerably lower, 3–5 Gy, aligning with observations in A-bomb survivors exposed as children. The reasons for these dose differences in radiosensitivity are not fully understood. Other important questions about the development of hypothyroidism after radiation exposure e.g., in utero, about the interaction between autoimmunity and hypofunction, and about the different effects of internal and external irradiation still must be answered.
KW  - thyroid
KW  - hypothyroidism
KW  - autoimmune thyroiditis
KW  - diagnostic medical radiation exposure
KW  - therapeutic medical radiation exposure (EBRT/ RAI)
KW  - other radiation exposure (atomic bombing/nuclear accidents)
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235653
SN  - 0300-9564
VL  - 127
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Petritsch, Bernhard
A1  - Buck, Andreas K.
A1  - Serfling, Sebastian E.
T1  - Pitfalls in PSMA-PET/CT: Intensive bone-marrow uptake in a case with polycythaemia vera
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - No abstract available.
KW  - bone-marrow
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235608
SN  - 1619-7070
VL  - 48
ER  - 
TY  - JOUR
A1  - Konijnenberg, Mark
A1  - Herrmann, Ken
A1  - Kobe, Carsten
A1  - Verburg, Frederik
A1  - Hindorf, Cecilia
A1  - Hustinx, Roland
A1  - Lassmann, Michael
T1  - EANM position paper on article 56 of the Council Directive 2013/59/Euratom (basic safety standards) for nuclear medicine therapy
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - The EC Directive 2013/59/Euratom states in article 56 that exposures of target volumes in nuclear medicine treatments shall be individually planned and their delivery appropriately verified. The Directive also mentions that medical physics experts should always be appropriately involved in those treatments. Although it is obvious that, in nuclear medicine practice, every nuclear medicine physician and physicist should follow national rules and legislation, the EANM considered it necessary to provide guidance on how to interpret the Directive statements for nuclear medicine treatments.

For this purpose, the EANM proposes to distinguish three levels in compliance to the optimization principle in the directive, inspired by the indication of levels in prescribing, recording and reporting of absorbed doses after radiotherapy defined by the International Commission on Radiation Units and Measurements (ICRU):

Most nuclear medicine treatments currently applied in Europe are standardized. The minimum requirement for those treatments is ICRU level 1 (“activity-based prescription and patient-averaged dosimetry”), which is defined by administering the activity within 10% of the intended activity, typically according to the package insert or to the respective EANM guidelines, followed by verification of the therapy delivery, if applicable.

Non-standardized treatments are essentially those in developmental phase or approved radiopharmaceuticals being used off-label with significantly (> 25% more than in the label) higher activities. These treatments should comply with ICRU level 2 (“activity-based prescription and patient-specific dosimetry”), which implies recording and reporting of the absorbed dose to organs at risk and optionally the absorbed dose to treatment regions.

The EANM strongly encourages to foster research that eventually leads to treatment planning according to ICRU level 3 (“dosimetry-guided patient-specific prescription and verification”), whenever possible and relevant.

Evidence for superiority of therapy prescription on basis of patient-specific dosimetry has not been obtained. However, the authors believe that a better understanding of therapy dosimetry, i.e. how much and where the energy is delivered, and radiobiology, i.e. radiation-related processes in tissues, are keys to the long-term improvement of our treatments.
KW  - nuclear medicine therapy
KW  - dosimetry
KW  - optimization
KW  - BSS directive
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235280
SN  - 1619-7070
VL  - 48
ER  - 
TY  - JOUR
A1  - Serfling, S.
A1  - Zhi, Y.
A1  - Schirbel, A.
A1  - Lindner, T.
A1  - Meyer, T.
A1  - Gerhard-Hartmann, E.
A1  - Lappa, C.
A1  - Hagen, R.
A1  - Hackenberg, S.
A1  - Buck, A. K.
A1  - Scherzad, A.
T1  - Improved cancer detection in Waldeyer’s tonsillar ring by \(^{68}\)Ga-FAPI PET/CT imaging
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Purpose
In cancer of unknown primary (CUP), positron emission tomography/computed tomography (PET/CT) with the glucose analog [\(^{18}\)F]FDG represents the standard imaging approach for localization of the malignant primary. Frequently, however, [\(^{18}\)F]FDG PET/CT cannot precisely distinguish between small occult tumors and chronic inflammation, especially in Waldeyer’s tonsillar ring. To improve the accuracy for detecting primary tumors in the Waldeyer’s tonsillar ring, the novel PET tracer [\(^{68}\)Ga]Ga-FAPI-4 for specific imaging of fibroblast activation protein (FAP) expression was used as a more specific target for cancer imaging.

Methods
Eight patients with suspicion of a malignant tumor in Waldeyer’s tonsillar ring or a CUP syndrome were examined. PET/CT scans with [\(^{18}\)F]-FDG and [\(^{68}\)Ga]Ga-FAPI-4 were performed for pre-operative tumor localization. After surgical resection, histopathological and immunohistochemical results were compared to PET/CT findings.

Results
Histopathology revealed a palatine or lingual tonsil carcinoma in all patients. In case of lymph node metastases smaller than 7 mm in size, the [\(^{18}\)F]FDG PET/CT detection rate of cervical lymph node metastases was higher than that of [\(^{68}\)Ga]FAPI PET/CT, while both tracers identified the primary tumors in all eight cases. The size of the primary and the lymph node metastases was directly correlated to the respective FAP expression, as detected by immunohistochemistry. The mean SUVmax for the primary tumors was 21.29 ± 7.97 for \(^{18}\)F-FDG and 16.06 ± 6.29 for \(^{68}\)Ga-FAPI, respectively (p = 0.2). The mean SUVmax for the healthy contralateral tonsils was 8.38 ± 2.45 for [\(^{18}\)F]FDG and 3.55 ± 0.47 for [\(^{68}\)Ga]FAPI (p < 0.001). The SUVmax ratio of [68Ga]FAPI was significantly different from [\(^{18}\)F] FDG (p = 0.03). Mean TBRmax for the [\(^{68}\)Ga]Ga-FAPI-4 tracer was markedly higher in comparison to [\(^{18}\)F]FDG (10.90 vs. 4.11).

Conclusion
Non-invasive imaging of FAP expression by [\(^{68}\)Ga]FAPI PET/CT resulted in a better visual detection of the malignant primary in CUP, as compared to [\(^{18}\)F]FDG imaging. However, the detection rate of lymph node metastases was inferior, presumably due to low FAP expression in small metastases. Nevertheless, by offering a detection method for primary tumors with the potential of lower false positive rates and thus avoiding biopsies, patients with CUP syndrome may benefit from [\(^{68}\)Ga]FAPI PET/CT imaging.
KW  - Waldeyer’s tonsillar ring
KW  - cancer of unknown primary (CUP)
KW  - positron emission tomography/computed tomography
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235271
SN  - 1619-7070
VL  - 48
ER  - 
TY  - JOUR
A1  - Steinhardt, Maximilian Johannes
A1  - Zhou, Xiang
A1  - Krummenast, Franziska
A1  - Meckel, Katharina
A1  - Nickel, Katharina
A1  - Böckle, David
A1  - Messerschmidt, Janin
A1  - Knorz, Sebastian
A1  - Dierks, Alexander
A1  - Heidemeier, Anke
A1  - Lapa, Constantin
A1  - Einsele, Hermann
A1  - Rasche, Leo
A1  - Kortüm, Klaus Martin
T1  - Sequential CD38 monoclonal antibody retreatment leads to deep remission in a patient with relapsed/refractory multiple myeloma
JF  - International Journal of Immunopathology and Pharmacology
N2  - We report on a currently 76-year-old female patient with relapsed/refractory (RR) multiple myeloma (MM) treated at our institution. This patient had received six lines of therapy including tandem autologous stem cell transplant, proteasome inhibitor, immunomodulatory drugs and CD38 antibody MOR202. At the last relapse, she progressed during treatment with pomalidomide and MOR202. In an individualized therapy concept, we started a multi-agent salvage therapy with pomalidomide, bortezomib, doxorubicin, dexamethasone, and CD38 antibody daratumumab (“Pom-PAD-Dara”), which resulted in a stringent complete remission with minimal residual disease (MRD) negativity after nine cycles. So far, our patient shows a progression free survival of more than 12 months. Our case demonstrates the feasibility of successful CD38 antibody retreatment in a patient with heavily pretreated CD38 antibody resistant MM.
KW  - CD38
KW  - MOR202
KW  - daratumumab
KW  - multiple myeloma
KW  - refractory
KW  - relapse
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236235
VL  - 34
ER  - 
TY  - JOUR
A1  - Isaias, Ioannis U.
A1  - Brumberg, Joachim
A1  - Pozzi, Nicoló G.
A1  - Palmisano, Chiara
A1  - Canessa, Andrea
A1  - Marotta, Giogio
A1  - Volkmann, Jens
A1  - Pezzoli, Gianni
T1  - Brain metabolic alterations herald falls in patients with Parkinson's disease
JF  - Annals of Clinical and Translational Neurology
N2  - Pathophysiological understanding of gait and balance disorders in Parkinson’s disease is insufficient and late recognition of fall risk limits efficacious followup to prevent or delay falls. We show a distinctive reduction of glucose metabolism in the left posterior parietal cortex, with increased metabolic activity in the cerebellum, in parkinsonian patients 6–8 months before their first fall episode. Falls in Parkinson’s disease may arise from altered cortical processing of body spatial orientation, possibly predicted by abnormal cortical metabolism.
KW  - Parkionson's disease
KW  - brain metabolic alterations
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235982
VL  - 7
IS  - 4
ER  - 
TY  - JOUR
A1  - Zhou, Xiang
A1  - Dierks, Alexander
A1  - Kertels, Olivia
A1  - Samnick, Samuel
A1  - Kircher, Malte
A1  - Buck, Andreas K.
A1  - Haertle, Larissa
A1  - Knorz, Sebastian
A1  - Böckle, David
A1  - Scheller, Lukas
A1  - Messerschmidt, Janin
A1  - Barakat, Mohammad
A1  - Truger, Marietta
A1  - Haferlach, Claudia
A1  - Einsele, Hermann
A1  - Rasche, Leo
A1  - Kortüm, K. Martin
A1  - Lapa, Constantin
T1  - The link between cytogenetics/genomics and imaging patterns of relapse and progression in patients with relapsed/refractory multiple myeloma: a pilot study utilizing 18F-FDG PET/CT
JF  - Cancers
N2  - Utilizing 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT), we performed this pilot study to evaluate the link between cytogenetic/genomic markers and imaging patterns in relapsed/refractory (RR) multiple myeloma (MM). We retrospectively analyzed data of 24 patients with RRMM who were treated at our institution between November 2018 and February 2020. At the last relapse/progression, patients had been treated with a median of three (range 1–10) lines of therapy. Six (25%) patients showed FDG avid extramedullary disease without adjacency to bone. We observed significantly higher maximum standardized uptake values (SUV\(_{max}\)) in patients harboring del(17p) compared with those without del(17p) (p = 0.025). Moreover, a high SUV\(_{max}\) of >15 indicated significantly shortened progression-free survival (PFS) (p = 0.01) and overall survival (OS) (p = 0.0002). One female patient exhibited biallelic TP53 alteration, i.e., deletion and mutation, in whom an extremely high SUV\(_{max}\) of 37.88 was observed. In summary, this pilot study suggested a link between del(17p)/TP53 alteration and high SUV\(_{max}\) on 18F-FDG PET/CT in RRMM patients. Further investigations are highly warranted at this point.
KW  - radiogenomics
KW  - 18F-FDG PET/CT
KW  - multiple myeloma
KW  - relapse
KW  - progression
KW  - pattern
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211157
SN  - 2072-6694
VL  - 12
IS  - 9
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Schröter, Nils
A1  - Blazhenets, Ganna
A1  - Frings, Lars
A1  - Volkmann, Jens
A1  - Lapa, Constantin
A1  - Jost, Wolfgang H.
A1  - Isaias, Ioannis U.
A1  - Meyer, Philipp T.
T1  - Differential diagnosis of parkinsonism: a head-to-head comparison of FDG PET and MIBG scintigraphy
JF  - NPJ Parkinsons Disease
N2  - [\(^{18}\)F]fluorodeoxyglucose (FDG) PET and [\(^{123}\)I]metaiodobenzylguanidine (MIBG) scintigraphy may contribute to the differential diagnosis of neurodegenerative parkinsonism. To identify the superior method, we retrospectively evaluated 54 patients with suspected neurodegenerative parkinsonism, who were referred for FDG PET and MIBG scintigraphy. Two investigators visually assessed FDG PET scans using an ordinal 6-step score for disease-specific patterns of Lewy body diseases (LBD) or atypical parkinsonism (APS) and assigned the latter to the subgroups multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal syndrome. Regions-of-interest analysis on anterior planar MIBG images served to calculate the heart-to-mediastinum ratio. Movement disorder specialists blinded to imaging results established clinical follow-up diagnosis by means of guideline-derived case vignettes. Clinical follow-up (1.7 +/- 2.3 years) revealed the following diagnoses: n = 19 LBD (n = 17 Parkinson's disease [PD], n = 1 PD dementia, and n = 1 dementia with Lewy bodies), n = 31 APS (n = 28 MSA, n = 3 PSP), n = 3 non-neurodegenerative parkinsonism; n = 1 patient could not be diagnosed and was excluded. Receiver operating characteristic analyses for discriminating LBD vs. non-LBD revealed a larger area under the curve for FDG PET than for MIBG scintigraphy at statistical trend level for consensus rating (0.82 vs. 0.69, p = 0.06; significant for investigator #1: 0.83 vs. 0.69, p = 0.04). The analysis of PD vs. MSA showed a similar difference (0.82 vs. 0.69, p = 0.11; rater #1: 0.83 vs. 0.69, p = 0.07). Albeit the notable differences in diagnostic performance did not attain statistical significance, the authors consider this finding clinically relevant and suggest that FDG PET, which also allows for subgrouping of APS, should be preferred.
KW  - clinical diagnosis
KW  - F-18-FDG PET
KW  - disease
KW  - dementia
KW  - accuracy
KW  - stimulation
KW  - guidelines
KW  - criteria
KW  - brain
KW  - risk
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230675
VL  - 6
ER  - 
TY  - JOUR
A1  - Janssen, Jan P.
A1  - Hoffmann, Jan V.
A1  - Kanno, Takayuki
A1  - Nose, Naoko
A1  - Grunz, Jan-Peter
A1  - Onoguchi, Masahisa
A1  - Chen, Xinyu
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
T1  - Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging
JF  - Scientific Reports
N2  - We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available \(^{99m}\)Tc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with \(^{99m}\)Tc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with similar to 100 MBq [\(^{99m}\)TcTc-MIBI or similar to 150 MBq [\(^{99m}\)Tc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1="very poor" to 5="very good". Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.
KW  - small animal SPECT
KW  - HMDP hydroxymethylene diphosphonate
KW  - skeletal
KW  - quality
KW  - scanner
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230616
VL  - 10
ER  - 
TY  - JOUR
A1  - Hoffmann, Jan V.
A1  - Janssen, Jan P.
A1  - Kanno, Takayuki
A1  - Shibutani, Takayuki
A1  - Onoguchi, Masahisa
A1  - Lapa, Constantin
A1  - Grunz, Jan-Peter
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
T1  - Performance evaluation of fifth-generation ultra-high-resolution SPECT system with two stationary detectors and multi-pinhole imaging
JF  - EJNMMI Physics
N2  - Background 
Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT\(^+\)). 

Methods 
The new U-SPECT5-E with two stationary detectors was used for acquiring data with \(^{99m}\)Tc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT\(^+\) for comparison. 

Results 
Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT\(^+\). In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT\(^+\)) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR. 

Conclusions 
While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.
KW  - small-animal imaging
KW  - SPECT
KW  - mouse
KW  - ollimator
KW  - post-reconstruction filtering
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230361
VL  - 7
ER  - 
TY  - JOUR
A1  - Fecher, David
A1  - Hofmann, Elisabeth
A1  - Buck, Andreas
A1  - Bundschuh, Ralph
A1  - Nietzer, Sarah
A1  - Dandekar, Gudrun
A1  - Walles, Thorsten
A1  - Walles, Heike
A1  - Lückerath, Katharina
A1  - Steinke, Maria
T1  - Human Organotypic Lung Tumor Models: Suitable For Preclinical \(^{18}\)F-FDG PET-Imaging
JF  - PLoS ONE
N2  - Development of predictable in vitro tumor models is a challenging task due to the enormous complexity of tumors in vivo. The closer the resemblance of these models to human tumor characteristics, the more suitable they are for drug-development and –testing. In the present study, we generated a complex 3D lung tumor test system based on acellular rat lungs. A decellularization protocol was established preserving the architecture, important ECM components and the basement membrane of the lung. Human lung tumor cells cultured on the scaffold formed cluster and exhibited an up-regulation of the carcinoma-associated marker mucin1 as well as a reduced proliferation rate compared to respective 2D culture. Additionally, employing functional imaging with 2-deoxy-2-[\(^{18}\)F]fluoro-D-glucose positron emission tomography (FDG-PET) these tumor cell cluster could be detected and tracked over time. This approach allowed monitoring of a targeted tyrosine kinase inhibitor treatment in the in vitro lung tumor model non-destructively. Surprisingly, FDG-PET assessment of single tumor cell cluster on the same scaffold exhibited differences in their response to therapy, indicating heterogeneity in the lung tumor model. In conclusion, our complex lung tumor test system features important characteristics of tumors and its microenvironment and allows monitoring of tumor growth and -metabolism in combination with functional imaging. In longitudinal studies, new therapeutic approaches and their long-term effects can be evaluated to adapt treatment regimes in future.
KW  - lung and intrathoracic tumors
KW  - trachea
KW  - adenocarcinoma of the lung
KW  - cancer treatment
KW  - secondary lung tumors
KW  - pulmonary imaging
KW  - extracellular matrix
KW  - collagens
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-179678
VL  - 11
IS  - 8
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Beykan, Seval
A1  - Higuchi, Takahiro
A1  - Lückerath, Katharina
A1  - Weich, Alexander
A1  - Scheurlen, Michael
A1  - Bluemel, Christina
A1  - Herrmann, Ken
A1  - Buck, Andreas K.
A1  - Lassmann, Michael
A1  - Lapa, Constantin
A1  - Hänscheid, Heribert
T1  - The impact of \(^{177}\)Lu-octreotide therapy on \(^{99m}\)Tc-MAG3 clearance is not predictive for late nephropathy
JF  - Oncotarget
N2  - Peptide Receptor Radionuclide Therapy (PRRT) for the treatment of neuroendocrine tumors may lead to kidney deterioration. This study aimed to evaluate the suitability of \(^{99m}\)Tc-mercaptoacetyltriglycine (\(^{99m}\)Tc-MAG3) clearance for the early detection of PRRT-induced changes on tubular extraction (TE). TE rate (TER) was measured prior to 128 PRRT cycles (7.6±0.4 GBq \(^{177}\)Lu-octreotate/octreotide each) in 32 patients. TER reduction during PRRT was corrected for age-related decrease and analyzed for the potential to predict loss of glomerular filtration (GF). The GF rate (GFR) as measure for renal function was derived from serum creatinine. The mean TER was 234 ± 53 ml/min/1.73 m² before PRRT (baseline) and 221 ± 45 ml/min/1.73 m² after a median follow-up of 370 days. The age-corrected decrease (mean: -3%, range: -27% to +19%) did not reach significance (p=0.09) but significantly correlated with the baseline TER (Spearman p=-0.62, p<0.001). Patients with low baseline TER showed an improved TER after PRRT, high decreases were only observed in individuals with high baseline TER. Pre-therapeutic TER data were inferior to plasma creatinine-derived GFR estimates in predicting late nephropathy. TER assessed by \(^{99m}\)Tc-MAG3­clearance prior to and during PRRT is not suitable as early predictor of renal injury and an increased risk for late nephropathy.
KW  - renal scintigraphy
KW  - neuroendocrine tumor
KW  - 177Lu
KW  - MAG3
KW  - PRRT
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177318
VL  - 7
IS  - 27
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Reiter, Theresa
A1  - Kircher, Malte
A1  - Schirbel, Andreas
A1  - Werner, Rudolf A.
A1  - Pelzer, Theo
A1  - Pizarro, Carmen
A1  - Skowasch, Dirk
A1  - Thomas, Lena
A1  - Schlesinger-Irsch, Ulrike
A1  - Thomas, Daniel
A1  - Bundschuh, Ralph A.
A1  - Bauer, Wolfgang R.
A1  - Gartner, Florian C.
T1  - Somatostatin receptor based PET/CT in patients with the suspicion of cardiac sarcoidosis: an initial comparison to cardiac MRI
JF  - Oncotarget
N2  - Diagnosis of cardiac sarcoidosis is often challenging. Whereas cardiac magnetic resonance imaging (CMR) and positron emission tomography/computed tomography (PET/CT) with \(^{18}\)F-fluorodeoxyglucose (FDG) are most commonly used to evaluate patients, PET/CT using radiolabeled somatostatin receptor (SSTR) ligands for visualization of inflammation might represent a more specific alternative. This study aimed to investigate the feasibility of SSTR–PET/CT for detecting cardiac sarcoidosis in comparison to CMR.

15 patients (6 males, 9 females) with sarcoidosis and suspicion on cardiac involvement underwent SSTR-PET/CT imaging and CMR. Images were visually scored. The AHA 17-segment model of the left myocardium was used for localization and comparison of inflamed myocardium for both imaging modalities. In semi-quantitative analysis, mean (SUV\(_{mean}\)) and maximum standardized uptake values (SUV\(_{max}\)) of affected myocardium were calculated and compared with both remote myocardium and left ventricular (LV) cavity.

SSTR-PET was positive in 7/15, CMR in 10/15 patients. Of the 3 CMR+/PET- subjects, one patient with minor involvement (<25% of wall thickness in CMR) was missed by PET. The remaining two CMR+/PET- patients displayed no adverse cardiac events during follow-up.

In the 17-segment model, PET/CT yielded 27 and CMR 29 positive segments. Overall concordance of the 2 modalities was 96.1% (245/255 segments analyzed). SUV\(_{mean}\) and SUV\(_{max}\) in inflamed areas were 2.0±1.2 and 2.6±1.2, respectively. The lesion-to-remote myocardium and lesion-to-LV cavity ratios were 1.8±0.2 and 1.9±0.2 for SUV\(_{mean}\) and 2.0±0.3 and 1.7±0.3 for SUV\(_{max}\), respectively.

Detection of cardiac sarcoidosis by SSTR-PET/CT is feasible. Our data warrant further analysis in larger prospective series.
KW  - sarcoidosis
KW  - PET
KW  - SSTR
KW  - somatostatin receptor
KW  - DOTATOC
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175423
VL  - 7
IS  - 47
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Beckl, Melanie
A1  - Dierks, Alexander
A1  - Schirbel, Andreas
A1  - Krebs, Markus
A1  - Buck, Andreas
A1  - Kübler, Hubert
A1  - Lapa, Constantin
A1  - Seitz, Anna Katharina
T1  - Detection Rate of \(^{68}\)Ga-PSMA Ligand PET/CT in Patients with Recurrent Prostate Cancer and Androgen Deprivation Therapy
JF  - Biomedicines
N2  - Prostate-specific membrane antigen (PSMA) ligand PET/CT enables the localization of tumor lesions in patients with recurrent prostate cancer, but it is unclear whether androgen deprivation therapy (ADT) influences diagnostic accuracy. The aim of this study was to evaluate the effect of ADT on the detection rate of \(^{68}\)Ga-PSMA ligand PET/CT. Thus, 399 patients with initial radical prostatectomy and 68Ga-PSMA ligand PET/CT during PSA relapse were retrospectively evaluated. Propensity score matching was used to create two balanced groups of 62 subjects who either did or did not receive ADT within six months before imaging. All \(^{68}\)Ga-PSMA ligand PET/CT were evaluated visually and with semiquantitative measures. The detection rate of tumor recurrence was significantly higher in the group with ADT (88.7% vs. 72.6%, p = 0.02) and improved with increasing PSA-levels in both groups. In subjects with pathological PET/CT and ADT, whole-body total lesion PSMA (p < 0.01) and PSMA-derived tumor volume (p < 0.01) were significantly higher than in those without ADT. More PSMA-positive lesions and higher PSMA-derived volumetric parameters in patients with ADT suggest that a better detection rate is related to a (biologically) more advanced disease stage. Due to high detection rates in patients with PSA-levels < 2 ng/mL, the withdrawal of ADT before PSMA ligand PET/CT cannot be recommended.
KW  - 68Ga-PSMA ligand PET/CT
KW  - androgen deprivation therapy
KW  - detection rate
KW  - recurrent prostate cancer
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219301
SN  - 2227-9059
VL  - 8
IS  - 11
ER  - 
TY  - JOUR
A1  - Chifu, Irina
A1  - Heinze, Britta
A1  - Fuss, Carmina T.
A1  - Lang, Katharina
A1  - Kroiss, Matthias
A1  - Kircher, Stefan
A1  - Ronchi, Cristina L.
A1  - Altieri, Barbara
A1  - Schirbel, Andreas
A1  - Fassnacht, Martin
A1  - Hahner, Stefanie
T1  - Impact of the Chemokine Receptors CXCR4 and CXCR7 on Clinical Outcome in Adrenocortical Carcinoma
JF  - Frontiers in Endocrinology
N2  - Chemokine receptors have a negative impact on tumor progression in several human cancers and have therefore been of interest for molecular imaging and targeted therapy. However, their clinical and prognostic significance in adrenocortical carcinoma (ACC) is unknown. The aim of this study was to evaluate the chemokine receptor profile in ACC and to analyse its association with clinicopathological characteristics and clinical outcome. A chemokine receptor profile was initially evaluated by quantitative PCR in 4 normal adrenals, 18 ACC samples and human ACC cell line NCI-H295. High expression of CXCR4 and CXCR7 in both healthy and malignant adrenal tissue and ACC cells was confirmed. In the next step, we analyzed the expression and cellular localization of CXCR4 and CXCR7 in ACC by immunohistochemistry in 187 and 84 samples, respectively. These results were correlated with clinicopathological parameters and survival outcome. We detected strong membrane expression of CXCR4 and CXCR7 in 50% of ACC samples. Strong cytoplasmic CXCR4 staining was more frequent among samples derived from metastases compared to primaries (p=0.01) and local recurrences (p=0.04). CXCR4 membrane staining positively correlated with proliferation index Ki67 (r=0.17, p=0.028). CXCR7 membrane staining negatively correlated with Ki67 (r=−0.254, p=0.03) but positively with tumor size (r=0.3, p=0.02). No differences in progression-free or overall survival were observed between patients with strong and weak staining intensities for CXCR4 or CXCR7. Taken together, high expression of CXCR4 and CXCR7 in both local tumors and metastases suggests that some ACC patients might benefit from CXCR4/CXCR7-targeted therapy.
KW  - chemokine receptor
KW  - prognosis
KW  - adrenocortical carcinoma
KW  - CXCR4
KW  - CXCR7
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216494
SN  - 1664-2392
VL  - 11
ER  - 
TY  - JOUR
A1  - Reiners, Christoph
A1  - Schneider, Rita
A1  - Platonova, Tamara
A1  - Fridman, Mikhail
A1  - Malzahn, Uwe
A1  - Mäder, Uwe
A1  - Vrachimis, Alexis
A1  - Bogdanova, Tatiana
A1  - Krajewska, Jolanta
A1  - Elisei, Rossella
A1  - Vaisman, Fernanda
A1  - Mihailovic, Jasna
A1  - Costa, Gracinda
A1  - Drozd, Valentina
T1  - Breast Cancer After Treatment of Differentiated Thyroid Cancer With Radioiodine in Young Females: What We Know and How to Investigate Open Questions. Review of the Literature and Results of a Multi-Registry Survey
JF  - Frontiers in Endocrinology
N2  - Published studies on the risk of radiation-induced second primary malignancy (SPM) after radioiodine treatment (RAI) of differentiated thyroid cancer (DTC) refer mainly to patients treated as middle-aged or older adults and are not easily generalizable to those treated at a younger age. Here we review available literature on the risk of breast cancer as an SPM after RAI of DTC with a focus on females undergoing such treatment in childhood, adolescence, or young adulthood. Additionally, we report the results of a preliminary international survey of patient registries from academic tertiary referral centers specializing in pediatric DTC. The survey sought to evaluate the availability of sufficient patient data for a potential international multicenter observational case–control study of females with DTC given RAI at an early age. Our literature review identified a bi-directional association of DTC and breast cancer. The general breast cancer risk in adult DTC survivors is low, ~2%, slightly higher in females than in males, but presumably lower, not higher, in those diagnosed as children or adolescents than in those diagnosed at older ages. RAI presumably does not substantially influence breast cancer risk after DTC. However, data from patients given RAI at young ages are sparse and insufficient to make definitive conclusions regarding age dependence of the risk of breast cancer as a SPM after RAI of DTC. The preliminary analysis of data from 10 thyroid cancer registries worldwide, including altogether 6,449 patients given RAI for DTC and 1,116 controls, i.e., patients not given RAI, did not show a significant increase of breast cancer incidence after RAI. However, the numbers of cases and controls were insufficient to draw statistically reliable conclusions, and the proportion of those receiving RAI at the earliest ages was too low.In conclusion, a potential international multicenter study of female patients undergoing RAI of DTC as children, adolescents, or young adults, with a sufficient sample size, is feasible. However, breast cancer screening of a larger cohort of DTC patients is not unproblematic for ethical reasons, due to the likely, at most slightly, increased risk of breast cancer post-RAI and the expected ~10% false-positivity rate which potentially produced substantial “misdiagnosis.”
KW  - differentiated thyroid carcinoma
KW  - radioiodine therapy
KW  - iodine-131
KW  - long-term complications
KW  - young females
KW  - childhood and adolescence
KW  - second primary malignancy
KW  - breast cancer
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-207766
SN  - 1664-2392
VL  - 11
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Heinrich, Marieke
A1  - Seitz, Anna Katharina
A1  - Brumberg, Joachim
A1  - Sokolakis, Ioannis
A1  - Kalogirou, Charis
A1  - Schirbel, Andreas
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Krebs, Markus
T1  - Metabolic Tumour Volume from PSMA PET/CT Scans of Prostate Cancer Patients during Chemotherapy — Do Different Software Solutions Deliver Comparable Results?
JF  - Journal of Clinical Medicine
N2  - (1) Background: Prostate-specific membrane antigen (PSMA)-derived tumour volume (PSMA-TV) and total lesion PSMA (TL-PSMA) from PSMA PET/CT scans are promising biomarkers for assessing treatment response in prostate cancer (PCa). Currently, it is unclear whether different software tools for assessing PSMA-TV and TL-PSMA produce comparable results. (2) Methods: \(^{68}\)Ga-PSMA PET/CT scans from n = 21 patients with castration-resistant PCa (CRPC) receiving chemotherapy were identified from our single-centre database. PSMA-TV and TL-PSMA were calculated with Syngo.via (Siemens) as well as the freely available Beth Israel plugin for FIJI (Fiji Is Just ImageJ) before and after chemotherapy. While statistical comparability was illustrated and quantified via Bland-Altman diagrams, the clinical agreement was estimated by matching PSMA-TV, TL-PSMA and relative changes of both variables during chemotherapy with changes in serum PSA (ΔPSA) and PERCIST (Positron Emission Response Criteria in Solid Tumors). (3) Results: Comparing absolute PSMA-TV and TL-PSMA as well as Bland–Altman plotting revealed a good statistical comparability of both software algorithms. For clinical agreement, classifying therapy response did not differ between PSMA-TV and TL-PSMA for both software solutions and showed highly positive correlations with BR. (4) Conclusions: due to the high levels of statistical and clinical agreement in our CRPC patient cohort undergoing taxane chemotherapy, comparing PSMA-TV and TL-PSMA determined by Syngo.via and FIJI appears feasible.
KW  - prostate-specific membrane antigen (PSMA)
KW  - metabolic tumour volume (MTV)
KW  - total lesion PSMA
KW  - biomarker
KW  - software
KW  - comparability
KW  - agreement
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-205893
SN  - 2077-0383
VL  - 9
IS  - 5
ER  - 
TY  - JOUR
A1  - Palmisano, Chiara
A1  - Brandt, Gregor
A1  - Vissani, Matteo
A1  - Pozzi, Nicoló G.
A1  - Canessa, Andrea
A1  - Brumberg, Joachim
A1  - Marotta, Giorgio
A1  - Volkmann, Jens
A1  - Mazzoni, Alberto
A1  - Pezzoli, Gianni
A1  - Frigo, Carlo A.
A1  - Isaias, Ioannis U.
T1  - Gait Initiation in Parkinson’s Disease: Impact of Dopamine Depletion and Initial Stance Condition
JF  - Frontiers in Bioengineering and Biotechnology
N2  - Postural instability, in particular at gait initiation (GI), and resulting falls are a major determinant of poor quality of life in subjects with Parkinson’s disease (PD). Still, the contribution of the basal ganglia and dopamine on the feedforward postural control associated with this motor task is poorly known. In addition, the influence of anthropometric measures (AM) and initial stance condition on GI has never been consistently assessed. The biomechanical resultants of anticipatory postural adjustments contributing to GI [imbalance (IMB), unloading (UNL), and stepping phase) were studied in 26 unmedicated subjects with idiopathic PD and in 27 healthy subjects. A subset of 13 patients was analyzed under standardized medication conditions and the striatal dopaminergic innervation was studied in 22 patients using FP-CIT and SPECT. People with PD showed a significant reduction in center of pressure (CoP) displacement and velocity during the IMB phase, reduced first step length and velocity, and decreased velocity and acceleration of the center of mass (CoM) at toe off of the stance foot. All these measurements correlated with the dopaminergic innervation of the putamen and substantially improved with levodopa. These results were not influenced by anthropometric parameters or by the initial stance condition. In contrast, most of the measurements of the UNL phase were influenced by the foot placement and did not correlate with putaminal dopaminergic innervation. Our results suggest a significant role of dopamine and the putamen particularly in the elaboration of the IMB phase of anticipatory postural adjustments and in the execution of the first step. The basal ganglia circuitry may contribute to defining the optimal referent body configuration for a proper initiation of gait and possibly gait adaptation to the environment.
KW  - gait initiation
KW  - Parkinson’s disease
KW  - basal ganglia
KW  - dopamine
KW  - base of support
KW  - anthropometric measurements
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200801
SN  - 2296-4185
VL  - 8
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Schreder, Martin
A1  - Schirbel, Andreas
A1  - Samnick, Samuel
A1  - Kortüm, Klaus Martin
A1  - Herrmann, Ken
A1  - Kropf, Saskia
A1  - Einsele, Herrmann
A1  - Buck, Andreas K.
A1  - Wester, Hans-Jürgen
A1  - Knop, Stefan
A1  - Lückerath, Katharina
T1  - [\(^{68}\)Ga]Pentixafor-PET/CT for imaging of chemokine receptor CXCR4 expression in multiple myeloma - comparison to [\(^{18}\)F]FDG and laboratory values
JF  - Theranostics
N2  - Chemokine (C-X-C motif) receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer including multiple myeloma (MM). Proof-of-concept of CXCR4-directed radionuclide therapy in MM has recently been reported. This study assessed the diagnostic performance of the CXCR4-directed radiotracer [\(^{68}\)Ga]Pentixafor in MM and a potential role for stratifying patients to CXCR4-directed therapies.

Thirty-five patients with MM underwent [\(^{68}\)Ga]Pentixafor-PET/CT for evaluation of eligibility for endoradiotherapy. In 19/35 cases, [\(^{18}\)F]FDG-PET/CT for correlation was available. Scans were compared on a patient and on a lesion basis. Tracer uptake was correlated with standard clinical parameters of disease activity.

[\(^{68}\)Ga]Pentixafor-PET detected CXCR4-positive disease in 23/35 subjects (66%). CXCR4-positivity at PET was independent from myeloma subtypes, cytogenetics or any serological parameters and turned out as a negative prognostic factor. In the 19 patients in whom a comparison to [\(^{18}\)F]FDG was available, [\(^{68}\)Ga]Pentixafor-PET detected more lesions in 4/19 (21%) subjects, [\(^{18}\)F]FDG proved superior in 7/19 (37%). In the remaining 8/19 (42%) patients, both tracers detected an equal number of lesions. [\(^{18}\)F]FDG-PET positivity correlated with [\(^{68}\)Ga]Pentixafor-PET positivity (p=0.018).

[\(^{68}\)Ga]Pentixafor-PET provides further evidence that CXCR4 expression frequently occurs in advanced multiple myeloma, representing a negative prognostic factor and a potential target for myeloma specific treatment. However, selecting patients for CXCR4 directed therapies and prognostic stratification seem to be more relevant clinical applications for this novel imaging modality, rather than diagnostic imaging of myeloma.
KW  - medicine
KW  - multiple myeloma
KW  - FDG
KW  - molecular imaging
KW  - CXCR4
KW  - PET
KW  - radionuclide therapy
KW  - theranostics
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172106
VL  - 7
IS  - 1
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Herrmann, Ken
A1  - Schirbel, Andreas
A1  - Hänscheid, Heribert
A1  - Lückerath, Katharina
A1  - Schottelius, Margret
A1  - Kircher, Malte
A1  - Werner, Rudolf A.
A1  - Schreder, Martin
A1  - Samnick, Samuel
A1  - Kropf, Saskia
A1  - Knop, Stefan
A1  - Buck, Andreas K.
A1  - Einsele, Hermann
A1  - Wester, Hans-Juergen
A1  - Kortüm, K. Martin
T1  - CXCR4-directed endoradiotherapy induces high response rates in extramedullary relapsed multiple myeloma
JF  - Theranostics
N2  - C-X-C-motif chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. We have recently reported promising first-in-man experience with CXCR4-directed endoradiotherapy (ERT) in multiple myeloma (MM).

Eight heavily pretreated MM patients underwent a total of 10 ERT cycles (7 patients with 1 cycle and a single patient with 3 cycles). ERT was administered in combination with chemotherapy and autologous stem cell support. End points were occurrence and timing of adverse events, progression-free and overall survival.

ERT was overall well tolerated without any unexpected acute adverse events or changes in vital signs. With absorbed tumor doses >30-70 Gy in intra- or extramedullary lesions, significant anti-myeloma activity was observed with 1 patient achieving complete remission and 5/8 partial remission. Directly after ERT major infectious complications were seen in one patient who died from sepsis 22 days after ERT, another patient with high tumor burden experienced lethal tumor lysis syndrome. Median progression-free survival was 54 days (range, 13-175), median overall survival was 223 days (range, 13-313). During follow-up (6 patients available), one patient died from infectious complications, 2/8 from disease progression, the remaining 3/8 patients are still alive.

CXCR4-directed ERT was well-tolerated and exerted anti-myeloma activity even at very advanced stage MM with presence of extramedullary disease. Further assessment of this novel treatment option is highly warranted.
KW  - medicine
KW  - multiple myeloma
KW  - PET
KW  - CXCR4
KW  - theranostics
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172095
VL  - 7
IS  - 6
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Garcia-Velloso, Maria J.
A1  - Lückerath, Katharina
A1  - Samnick, Samuel
A1  - Schreder, Martin
A1  - Otero, Paula Rodriguez
A1  - Schmid, Jan-Stefan
A1  - Herrmann, Ken
A1  - Knop, Stefan
A1  - Buck, Andreas K.
A1  - Einsele, Hermann
A1  - San-Miguel, Jesus
A1  - Kortüm, Klaus Martin
T1  - \(^{11}\)C-methionine-PET in multiple myeloma: a combined study from two different institutions
JF  - Theranostics
N2  - \(^{11}\)C-methionine (MET) has recently emerged as an accurate marker of tumor burden and disease activity in patients with multiple myeloma (MM). This dual-center study aimed at further corroboration of the superiority of MET as positron emission tomography (PET) tracer for staging and re-staging MM, as compared to \(^{18}\)F-2`-deoxy-2`-fluoro-D-glucose (FDG).
78 patients with a history of solitary plasmacytoma (n=4), smoldering MM (SMM, n=5), and symptomatic MM (n=69) underwent both MET- and FDG-PET/computed tomography (CT) at the University Centers of Würzburg, Germany and Navarra, Spain. Scans were compared on a patient and on a lesion basis. Inter-reader agreement was also evaluated. In 2 patients, tumor biopsies for verification of discordant imaging results were available.
MET-PET detected focal lesions (FL) in 59/78 subjects (75.6%), whereas FDG-PET/CT showed lesions in only 47 patients (60.3%; p<0.01), accordingly disease activity would have been missed in 12 patients. Directed biopsies of discordant results confirmed MET-PET/CT results in both cases.
MET depicted more FL in 44 patients (56.4%; p<0.01), whereas in two patients (2/78), FDG proved superior. In the remainder (41.0%, 32/78), both tracers yielded comparable results. Inter-reader agreement for MET was higher than for FDG (κ = 0.82 vs κ = 0.72).
This study demonstrates higher sensitivity of MET in comparison to standard FDG to detect intra- and extramedullary MM including histologic evidence of FDG-negative, viable disease exclusively detectable by MET-PET/CT. MET holds the potential to replace FDG as functional imaging standard for staging and re-staging of MM.
KW  - medicine
KW  - PET/CT
KW  - \(^{11}\)C-methionine
KW  - multiple myeloma
KW  - FDG
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172038
VL  - 7
IS  - 11
ER  - 
TY  - THES
A1  - Eißler, Christoph Marcel
T1  - Assessment of the left ventricular systolic and diastolic function in rats using electrocardiogram-gated cardiac positron emission tomography
T1  - Bestimmung der linksventrikulären systolischen und diastolischen Funktion in Ratten durch Elektrokardiogramm-getriggerte kardiale Positronen-Emissions-Tomographie
N2  - DD is a cardiac disturbance, which has gained increasing importance in recent years due to its important role in different cardiac disease and cardiomyopathies including ischemic cardiomyopathy, arterial hypertension and diabetic cardiomyopathy. 
ECG-gated 18F-FDG PET is an imaging technique, that can distinguish between districts of myocardial viability and myocardial scars and further provides information of great interest on the efficacy of experimental approaches designed to improve the cardiac function and/or myocardial metabolism in experimental small animal models. However, ECG-gated 18F-FDG PET is a technique whose feasibility in the assessment of the LV diastolic function in small animals has not been a subject of study.
In this thesis, the ability of the ECG-gated 18F-FDG PET for the assessment of both the systolic and diastolic function in eight control rats and in seven ZDF rats, which are an experimental animal model mimicking T2DM conditions and diabetic related complications in humans including DCM, has been investigated The ECG-gated 18F-FDG PET imaging was performed under hyperinsulinemic-euglycemic clamping and the data were stored in list mode files and retrospectively reconstructed. The systolic and diastolic parameters were achieved from the time/volume and the time/filling curve calculated from the software HFV. Additionally, the influence of the number of gates per cardiac cycle on the LV volumes and function parameters has been studied.
Hyperinsulinemic-euglycemic clamp procedure and blood glucose measurement did confirm the development of a manifest diabetes in the ZDF rats at the timepoint of the experiments.
Regarding the systolic parameters, no significant difference could be detected between the ZDF and ZL rats. The values for the CO were similar in both groups, which demonstrates a similar LV systolic function in the ZDF and the ZL rats at the age of 13 weeks. Values for the systolic parameters are in good line with previous PET, MRI and cardiac catheterization-based studies in diabetic rats.
The main finding of this study was that by using in vivo ECG-gated 18F-FDG PET and the software HFV, reliable diastolic parameters could be calculated. Moreover, it was possible to detect the presence of a mild impaired diastolic filling in the ZDF rats in absence of any systolic alteration. This impaired diastolic function in an early stage of diabetes could also be detected by other investigators, who used echocardiography or cardiac catheterization. Therefore, this is the first study showing, that the assessment of the diastolic function in rats can be carried out by ECG-gated 18F-FDG PET imaging.
In conclusion, additionally to calculating LV volumes and LV EF, ECG-gated 18F-FDG PET can evaluate the diastolic function of healthy and diabetic rats and is able to detect a DD in ZDF rats.
N2  - Die DD ist eine Störung der Herzdynamik, welche, aufgrund ihrer Beteiligung in verschiedenen Herzerkrankungen und Kardiomyopathien wie der ischämischen Kardiomyopathie, der arteriellen Hypertonie und der diabetischen Kardiomyopathie, in den letzten Jahren zunehmend in das Interessenzentrum der Herzforschung gerückt ist.
Die EKG-getriggerte 18F-FDG PET ist eine Bildgebungsmethode, welche die Unterscheidung von vitalem Myokard und Narben ermöglicht und zusätzlich noch in der Lage ist, wichtige Informationen zu erheben, welche von Bedeutung für die Beurteilung von experimentelle Behandlungen zur Verbesserung der Herzfunktion und/oder des kardialen Stoffwechsels in präklinischen Tiermodellen sind. Trotz dieser Möglichkeiten wurde bisher noch nicht die Fähigkeit der EKG-getriggerten 18F-FDG PET zur Bestimmung der LV diastoischen Funktion in Kleintiermodellen untersucht.
Deshalb wurde in dieser Arbeit das Potential der EKG-getriggerten 18F-FDG PET in Bezug auf die Bestimmung der LV systolischen und diastolischen Funktion in acht Kontrollratten (ZL) und sieben ZDF-Ratten, welche eine experimentelles Tiermodell für T2DM und die damit verbundenen Komplikationen einschließlich der diabetischen Kardiomyopathie sind, untersucht. Die EKG-getriggerte 18F-FDG PET wurde unter der hyperinsulinämischen euglykämischen Klemm Methode durchgeführt, die Daten in „list-mode“ Dateien gespeichert und retrospektiv rekonstruiert. Die Berechnung der LV systolischen und diastolischen Parameter erfolge aus der Zeit-Volumen-Kurve und der Zeit-Füllungs-Kurve durch das Programm HFV. Zudem wurde der Einfluss der pro Rekonstruktion verwendeten „frames“ pro kardialen Zyklus auf die LV Volumina und die linksventrikulären Funktionsparameter untersucht.
Durch die hyperinsulinämische euglykämische Klemm Methode und durch Blutglukose Messungen konnte die Entwicklung eines manifesten Diabetes zum Zeitpunkt der Experimente in den ZDF Ratten nachgewiesen werden.
Es konnte kein signifikanter Unterschied zwischen den systolischen Parametern der ZDF und der ZL Ratten gefunden werden. Der kardiale Auswurf war nahezu identisch in den beiden Gruppen zum Zeitpunkt der Experimente, was eine vergleichbare systolische Funktion in beiden Gruppen demonstriert. Die erhobenen Werte für die systolischen Parameter befinden sich in guter Übereinstimmung mit den Werten der Literatur von vorherigen PET, MRT und Katheter-gestützten Experimenten in diabetischen Rattenmodellen.
Ein wichtiges Ergebnis dieser Arbeit ist die Erhebung von verlässlichen diastolischen Parametern durch den kombinierten Einsatz von EKG-getriggerter 18F-FDG PET und HFV. Zudem war es möglich, eine gestörte diastolische Füllung des LV in den ZDF Ratten nachzuweisen, in Abwesenheit von systolischen Funktionseinschränkungen. 
Eine Beeinträchtigung der diastolischen Funktion in der frühen Phase des Diabetes wurde bereits in anderen Rattenstudien mittels Echokardiografie und Katheter basierten Untersuchungen gezeigt. Dennoch ist dies hier die erste Studie, welche demonstriert, dass die Bestimmung der diastolischen Funktion auch mit Hilfe der EKG-getriggerten 18F-FDG PET durchgeführt werden kann.
In Zusammenfassung lässt sich festhalten, das zusätzlich zu der Bestimmung der LV-Volumina und der LVEF durch EKG-getriggerten 18F-FDG PET auch die Bestimmung der diastolischen Funktion in gesunden und diabetischen Ratten möglich ist und dass durch EKG-getriggerten 18F-FDG PET die Identifikation einer DD in ZDF Ratten möglich ist.
KW  - Positronen-Emissions-Tomografie
KW  - preclinical PET
KW  - ECG-gated PET
KW  - diastolic dysfunction
KW  - diabetic cardiomyopathy
KW  - HFpEF
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219765
ER  - 
TY  - JOUR
A1  - Da Vià, Matteo Claudio
A1  - Solimando, Antonio Giovanni
A1  - Garitano-Trojaola, Andoni
A1  - Barrio, Santiago
A1  - Munawar, Umair
A1  - Strifler, Susanne
A1  - Haertle, Larissa
A1  - Rhodes, Nadine
A1  - Vogt, Cornelia
A1  - Lapa, Constantin
A1  - Beilhack, Andreas
A1  - Rasche, Leo
A1  - Einsele, Hermann
A1  - Kortüm, K. Martin
T1  - CIC Mutation as a Molecular Mechanism of Acquired Resistance to Combined BRAF‐MEK Inhibition in Extramedullary Multiple Myeloma with Central Nervous System Involvement
JF  - The Oncologist
N2  - Combined MEK‐BRAF inhibition is a well‐established treatment strategy in BRAF‐mutated cancer, most prominently in malignant melanoma with durable responses being achieved through this targeted therapy. However, a subset of patients face primary unresponsiveness despite presence of the activating mutation at position V600E, and others acquire resistance under treatment. Underlying resistance mechanisms are largely unknown, and diagnostic tests to predict tumor response to BRAF‐MEK inhibitor treatment are unavailable.

Multiple myeloma represents the second most common hematologic malignancy, and point mutations in BRAF are detectable in about 10% of patients. Targeted inhibition has been successfully applied, with mixed responses observed in a substantial subset of patients mirroring the widespread spatial heterogeneity in this genomically complex disease. Central nervous system (CNS) involvement is an extremely rare, extramedullary form of multiple myeloma that can be diagnosed in less than 1% of patients. It is considered an ultimate high‐risk feature, associated with unfavorable cytogenetics, and, even with intense treatment applied, survival is short, reaching less than 12 months in most cases. Here we not only describe the first patient with an extramedullary CNS relapse responding to targeted dabrafenib and trametinib treatment, we furthermore provide evidence that a point mutation within the capicua transcriptional repressor (CIC) gene mediated the acquired resistance in this patient.
KW  - Multiple myeloma
KW  - Extramedullary disease
KW  - Capicua transcriptional repressor
KW  - Drug resistance
KW  - BRAF mutation
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219549
VL  - 25
IS  - 2
ER  - 
TY  - THES
A1  - Saam, Marian
T1  - In-vitro-Untersuchung zum Einfluss von Therapeutika auf die PSMA- und CXCR4-Rezeptorexpression in humanen Prostatakarzinomzelllinien
T1  - Effect of therapeutic agents an PSMA- and CXCR4-receptorexpression: In-vitro-study of human prostate cancer cell lines
N2  - Die therapeutischen Möglichkeiten des metastasierten Prostatakarzinoms (Pca) haben sich durch die neuen Substanzen Docetaxel und Abirateron deutlich verbessert.
Das prostataspezifische Membranantigen (PSMA) stellt für die Diagnose und Therapie des Pca´s einen vielversprechenden Angriffspunkt dar. PSMA wird in Prostatakarzinomzellen überexprimiert und dient als Zielstruktur für nicht-invasives bildgebendes Verfahren und Lutetium-177-PSMA-Radioligandentherapie als Therapieoption.
Der CXCR4-Rezeptor wird an unterschiedlichen Zelltypen und Organen exprimiert. Seine Überexpression wird mit einer Metastasierung und schlechter Prognose assoziiert.
Gallium-68-PSMA PET/CT liefert genaue Kenntnisse bezüglich Ausbreitung und Fortschreiten des Tumorgeschehens.
Die vorliegende Arbeit untersucht die Zusammenhänge zwischen Expression von PSMA und CXCR4 in Verbindung mit etablierten Therapeutika und versucht Wege aufzuzeichnen, welche durch Erhöhung der PSMA-Expression zur verbesserten Sensitivität des PSMA PET/CT führen könnten, wodurch der personalisierte Therapieansatz weiter optimiert werden kann.
N2  - Novel therapeutic agents such as docetaxel and abiraterone have significantly improved treatment strategies for metastatic prostate cancer in recent years.
Prostate-specific membrane antigen (PSMA) represents a promising target for diagnosis and therapy of prostate cancer. PSMA is over expressed in prostate cancer cells providing a target structure for non-invasive imaging and Lutetium-177-PSMA radioligand therapy.
The CXCR4-receptor is expressed on different cell types and organs. Its over expression is associated with metastasis and poor prognosis.
PET/CT imaging with Gallium-68-labelled PSMA ligands provide relevant information regarding tumor staging and progression.
The present study investigates the interaction between expression of PSMA and CXCR4 considering established therapeutic agents to improve sensitivity of PSMA PET/CT imaging and optimize personalized cancer medicine.
KW  - psma
KW  - CXCR4
KW  - PET/CT
KW  - PSMA-Rezeptorexpression
KW  - CXCR4-Rezeptorexpression
KW  - Prostatakarzinom
KW  - PET/CT imaging
KW  - Gallium-68 PET/CT
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219163
ER  - 
TY  - JOUR
A1  - Schumann, Sarah
A1  - Scherthan, Harry
A1  - Frank, Torsten
A1  - Lapa, Constantin
A1  - Müller, Jessica
A1  - Seifert, Simone
A1  - Lassmann, Michael
A1  - Eberlein, Uta
T1  - DNA Damage in Blood Leukocytes of Prostate Cancer Patients Undergoing PET/CT Examinations with [\(^{68}\)Ga]Ga-PSMA I&T
JF  - Cancers
N2  - The aim was to investigate the induction and repair of radiation-induced DNA double-strand breaks (DSBs) as a function of the absorbed dose to the blood of patients undergoing PET/CT examinations with [68Ga]Ga-PSMA. Blood samples were collected from 15 patients before and at four time points after [68Ga]Ga-PSMA administration, both before and after the PET/CT scan. Absorbed doses to the blood were calculated. In addition, blood samples with/without contrast agent from five volunteers were irradiated ex vivo by CT while measuring the absorbed dose. Leukocytes were isolated, fixed, and stained for co-localizing γ-H2AX+53BP1 DSB foci that were enumerated manually. In vivo, a significant increase in γ-H2AX+53BP1 foci compared to baseline was observed at all time points after administration, although the absorbed dose to the blood by 68Ga was below 4 mGy. Ex vivo, the increase in radiation-induced foci depended on the absorbed dose and the presence of contrast agent, which could have caused a dose enhancement. The CT-dose contribution for the patients was estimated at about 12 mGy using the ex vivo calibration. The additional number of DSB foci induced by CT, however, was comparable to the one induced by 68Ga. The significantly increased foci numbers after [68Ga]Ga-PSMA administration may suggest a possible low-dose hypersensitivity.
KW  - DNA double-strand breaks
KW  - γ-H2AX
KW  - 53BP1
KW  - nuclear medicine
KW  - dosimetry
KW  - Ga-68
KW  - PSMA
KW  - PET/CT
KW  - contrast agent
KW  - prostate cancer
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200585
SN  - 2072-6694
VL  - 12
IS  - 2
ER  - 
TY  - JOUR
A1  - Buck, Andreas
A1  - Decristoforo, Clemens
T1  - Highlights lecture EANM 2015: the search for nuclear medicine's superheroes
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - The EANM 2015 Annual Congress, held from October 10th to 14th in Hamburg, Germany, was outstanding in many respects. With 5550 participants, this was by far the largest European congress concerning nuclear medicine. More than 1750 scientific presentations were submitted, with more than 250 abstracts from young scientists, indicating that the future success of our discipline is fuelled by a high number of young individuals becoming involved in a multitude of scientific activities. Significant improvements have been made in molecular imaging of cancer, particularly in prostate cancer. PSMA-directed PET/CT appears to become a new gold standard for staging and restaging purposes. Novel tumour specific compounds have shown their potential for target identification also in other solid neoplasms and further our understanding of tumour biology and heterogeneity. In addition, a variety of nuclear imaging techniques guiding surgical interventions have been introduced. A particular focus of the congress was put on targeted, radionuclide based therapies. Novel theranostic concepts addressing also tumour entities with high incidence rates such as prostate cancer, melanoma, and lymphoma, have shown effective anti-tumour activity. Strategies have been presented to improve further already established therapeutic regimens such as somatostatin receptor based radio receptor therapy for treating advanced neuroendocrine tumours. Significant contributions were presented also in the neurosciences track. An increasing number of target structures of high interest in neurology and psychiatry are now available for PET and SPECT imaging, facilitating specific imaging of different subtypes of dementia and movement disorders as well as neuroinflammation. Major contributions in the cardiovascular track focused on further optimization of cardiac perfusion imaging by reducing radiation exposure, reducing scanning time, and improving motion correction. Besides coronary artery disease, many contributions focused on cardiac inflammation, cardiac sarcoidosis, and specific imaging of large vessel vasculitis. The physics and instrumentation track included many highlights such as novel, high resolution scanners. The most noteworthy news and developments of this meeting were summarized in the highlights lecture. Only 55 scientific contributions were mentioned, and hence they represent only a brief summary, which is outlined in this article. For a more detailed view, all presentations can be accessed by the online version of the European Journal of Nuclear Medicine and Molecular Imaging (Volume 42, Supplement 1).
KW  - Conjugate arc therapy
KW  - Phase-II
KW  - 18F-FDG PET/CT
KW  - Highlights Lecture
KW  - Molecular Imaging
KW  - Prostate-cancer
KW  - Radionuclide therapy
KW  - Myocardial perfusion
KW  - Preclinical evaluation
KW  - Targeted therapy
KW  - Thyroid cancer
KW  - SPECT
KW  - 2015
KW  - EANM
KW  - Hamburg
KW  - Physics and instrumentation
KW  - Radiopharmacy
KW  - Oncology
KW  - Radionuclide Therapy
KW  - Cardiology
KW  - Neurosciences
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187613
VL  - 43
IS  - 10
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Wakabayashi, Hiroshi
A1  - Chen, Xinyu
A1  - Hayakawa, Nobuyuki
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
A1  - Javadi, Mehrbod S.
A1  - Robinson, Simon
A1  - Higuchi, Takahiro
T1  - Ventricular distribution pattern of the novel sympathetic nerve PET radiotracer \(^{18}\)F-LMI1195 in Rabbit Hearts
JF  - Scientific Reports
N2  - We aimed to determine a detailed regional ventricular distribution pattern of the novel cardiac nerve PET radiotracer \(^{18}\)F-LMI1195 in healthy rabbits. Ex-vivo high resolution autoradiographic imaging was conducted to identify accurate ventricular distribution of \(^{18}\)F-LMI1195. In healthy rabbits, \(^{18}\)F-LMI1195 was administered followed by the reference perfusion marker \(^{201}\)Tl for a dual-radiotracer analysis. After 20 min of \(^{18}\)F-LMI1195 distribution time, the rabbits were euthanized, the hearts were extracted, frozen, and cut into 20-μm short axis slices. Subsequently, the short axis sections were exposed to a phosphor imaging plate to determine \(^{18}\)F-LMI1195 distribution (exposure for 3 h). After complete \(^{18}\)F decay, sections were re-exposed to determine 201Tl distribution (exposure for 7 days). For quantitative analysis, segmental regions of Interest (ROIs) were divided into four left ventricular (LV) and a right ventricular (RV) segment on mid-ventricular short axis sections. Subendocardial, mid-portion, and subepicardial ROIs were placed on the LV lateral wall. \(^{18}\)F-LMI1195 distribution was almost homogeneous throughout the LV wall without any significant differences in all four LV ROIs (anterior, posterior, septal and lateral wall, 99 ± 2, 94 ± 5, 94 ± 4 and 97 ± 3%LV, respectively, n.s.). Subepicardial \(^{201}\)Tl uptake was significantly lower compared to the subendocardial portion (subendocardial, mid-portion, and subepicardial activity: 90 ± 3, 96 ± 2 and *80 ± 5%LV, respectively, *p < 0.01 vs. mid-portion). This was in contradistinction to the transmural wall profile of \(^{18}\)F-LMI1195 (90 ± 4, 96 ± 5 and 84 ± 4%LV, n.s.). A slight but significant discrepant transmural radiotracer distribution pattern of \(^{201}\)Tl in comparison to \(^{18}\)F-LMI1195 may be a reflection of physiological sympathetic innervation and perfusion in rabbit hearts.
KW  - Cardiovascular diseases
KW  - Heart failure
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202707
VL  - 9
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Derlin, Thorsten
A1  - Lapa, Constantin
A1  - Sheikbahaei, Sara
A1  - Higuchi, Takahiro
A1  - Giesel, Frederik L.
A1  - Behr, Spencer
A1  - Drzezga, Alexander
A1  - Kimura, Hiroyuki
A1  - Buck, Andreas K.
A1  - Bengel, Frank M.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Rowe, Steven P.
T1  - \(^{18}\)F-labeled, PSMA-targeted radiotracers: leveraging the advantages of radiofluorination for prostate cancer molecular imaging
JF  - Theranostics
N2  - Prostate-specific membrane antigen (PSMA)-targeted PET imaging for prostate cancer with \(^{68}\)Ga-labeled compounds has rapidly become adopted as part of routine clinical care in many parts of the world. However, recent years have witnessed the start of a shift from \(^{68}\)Ga- to \(^{18}\)F-labeled PSMA-targeted compounds. The latter imaging agents have several key advantages, which may lay the groundwork for an even more widespread adoption into the clinic. First, facilitated delivery from distant suppliers expands the availability of PET radiopharmaceuticals in smaller hospitals operating a PET center but lacking the patient volume to justify an onsite \(^{68}\)Ge/\(^{68}\)Ga generator. Thus, such an approach meets the increasing demand for PSMA-targeted PET imaging in areas with lower population density and may even lead to cost-savings compared to in-house production. Moreover, \(^{18}\)F-labeled radiotracers have a higher positron yield and lower positron energy, which in turn decreases image noise, improves contrast resolution, and maximizes the likelihood of detecting subtle lesions. In addition, the longer half-life of 110 min allows for improved delayed imaging protocols and flexibility in study design, which may further increase diagnostic accuracy. Moreover, such compounds can be distributed to sites which are not allowed to produce radiotracers on-site due to regulatory issues or to centers without access to a cyclotron. In light of these advantageous characteristics, \(^{18}\)F-labeled PSMA-targeted PET radiotracers may play an important role in both optimizing this transformative imaging modality and making it widely available. We have aimed to provide a concise overview of emerging \(^{18}\)F-labeled PSMA-targeted radiotracers undergoing active clinical development. Given the wide array of available radiotracers, comparative studies are needed to firmly establish the role of the available \(^{18}\)F-labeled compounds in the field of molecular PCa imaging, preferably in different clinical scenarios.
KW  - Radiofluorine
KW  - prostate-specific membrane antigen
KW  - prostate cancer
KW  - \(^{18}\)F
KW  - PSMA
KW  - \(^{68}\)Ga
KW  - theranostics
KW  - radioligand therapy
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202559
SN  - 1838-7640
VL  - 10
IS  - 1
ER  - 
TY  - JOUR
A1  - Breun, Maria
A1  - Monoranu, Camelia M.
A1  - Kessler, Almuth F.
A1  - Matthies, Cordula
A1  - Löhr, Mario
A1  - Hagemann, Carsten
A1  - Schirbel, Andreas
A1  - Rowe, Steven P.
A1  - Pomper, Martin G.
A1  - Buck, Andreas K.
A1  - Wester, Hans-Jürgen
A1  - Ernestus, Ralf-Ingo
A1  - Lapa, Constantin
T1  - [\(^{68}\)Ga]-Pentixafor PET/CT for CXCR4-mediated imaging of vestibular schwannomas
JF  - Frontiers in Oncology
N2  - We have recently demonstrated CXCR4 overexpression in vestibular schwannomas (VS). This study investigated the feasibility of CXCR4-directed positron emission tomography/computed tomography (PET/CT) imaging of VS using the radiolabeled chemokine ligand [\(^{68}\)Ga]Pentixafor.

Methods: 4 patients with 6 primarily diagnosed or pre-treated/observed VS were enrolled. All subjects underwent [\(^{68}\)Ga]Pentixafor PET/CT prior to surgical resection. Images were analyzed visually and semi-quantitatively for CXCR4 expression including calculation of tumor-to-background ratios (TBR). Immunohistochemistry served as standard of reference in three patients.

Results: [\(^{68}\)Ga]Pentixafor PET/CT was visually positive in all cases. SUV\(_{mean}\) and SUV\(_{max}\) were 3.0 ± 0.3 and 3.8 ± 0.4 and TBR\(_{mean}\) and TBR\(_{max}\) were 4.0 ± 1.4 and 5.0 ± 1.7, respectively. Histological analysis confirmed CXCR4 expression in tumors.

Conclusion: Non-invasive imaging of CXCR4 expression using [\(^{68}\)Ga]Pentixafor PET/CT of VS is feasible and could prove useful for in vivo assessment of CXCR4 expression.
KW  - vestibular schwannoma
KW  - CXCR4
KW  - PET/CT
KW  - molecular imaging
KW  - Pentixafor
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201863
VL  - 9
IS  - 503
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Kircher, Stefan
A1  - Higuchi, Takahiro
A1  - Kircher, Malte
A1  - Schirbel, Andreas
A1  - Wester, Hans-Jürgen
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
T1  - CXCR4-directed imaging in solid tumors
JF  - Frontiers in Oncology
N2  - Despite histological evidence in various solid tumor entities, available experience with CXCR4-directed diagnostics and endoradiotherapy mainly focuses on hematologic diseases. With the goal of expanding the application of CXCR4 theranostics to solid tumors, we aimed to elucidate the feasibility of CXCR4-targeted imaging in a variety of such neoplasms.
Methods: Nineteen patients with newly diagnosed, treatment-naïve solid tumors including pancreatic adenocarcinoma or neuroendocrine tumor, cholangiocarcinoma, hepatocellular carcinoma, renal cell carcinoma, ovarian cancer, and prostate cancer underwent [\(^{68}\)Ga]Pentixafor PET/CT. CXCR4-mediated uptake was assessed both visually and semi-quantitatively by evaluation of maximum standardized uptake values (SUV\(_{max}\)) of both primary tumors and metastases. With physiologic liver uptake as reference, tumor-to-background ratios (TBR) were calculated. [\(^{68}\)Ga]Pentixafor findings were further compared to immunohistochemistry and [\(^{18}\)F]FDG PET/CT.
Results: On [\(^{68}\)Ga]Pentixafor PET/CT, 10/19 (52.6%) primary tumors were visually detectable with a median SUVmax of 5.4 (range, 1.7–16.0) and a median TBR of 2.6 (range, 0.8–7.4), respectively. The highest level of radiotracer uptake was identified in a patient with cholangiocarcinoma (SUVmax, 16.0; TBR, 7.4). The relatively low uptake on [\(^{68}\)Ga]Pentixafor was also noted in metastases, exhibiting a median SUVmax of 4.5 (range, 2.3–8.8; TBR, 1.7; range, 1.0–4.1). A good correlation between uptake on [\(^{68}\)Ga]Pentixafor and histological derived CXCR4 expression was noted (R = 0.62, P < 0.05). In the 3 patients in whom [\(^{18}\)F]FDG PET/CT was available, [\(^{68}\)Ga]Pentixafor exhibited lower uptake in all lesions.
Conclusions: In this cohort of newly diagnosed, treatment-naïve patients with solid malignancies, CXCR4 expression as detected by [\(^{68}\)Ga]Pentixafor-PET/CT and immunohistochemistry was rather moderate. Thus, CXCR4-directed imaging may not play a major role in the management of solid tumors in the majority of patients.
KW  - CXCR4
KW  - [68Ga]Pentixafor
KW  - theranostics
KW  - solid tumors
KW  - chemokine receptor
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195678
SN  - 2234-943X
VL  - 9
IS  - 770
ER  - 
TY  - THES
A1  - Soares Machado, Jéssica
T1  - Dosimetry-based Assessment of Radiation-associated Cancer risk for \(^9\)\(^9\)\(^m\)Tc-MAG3 Scans in Infants and Optimization of Administered Activities for \(^6\)\(^8\)Ga-labelled Peptides in Children and Adolescents
T1  - Dosimetrie-basierte Abschätzung des strahlungsassoziierten Krebsrisikos für \(^9\)\(^9\)\(^m\)Tc-MAG3-Scans bei Säuglingen und Optimierung der verabreichten Aktivitäten für \(^6\)\(^8\)Ga-markierte Peptide bei Kindern und Jugendlichen
N2  - In 2006, 0.18 Mio pediatric nuclear medicine diagnostic exams were performed worldwide. However, for most of the radiopharmaceuticals used data on biokinetics and, as a consequence on dosimetry, are missing or have not been made publicly available. Therefore, most of the dosimetry assessments presented today for diagnostic agents in children and adolescents rely on the biokinetics data of adults. Even for one of the most common nuclear medicine exams for this patient group, renal scintigraphy with 99mTc-MAG3 for assessing renal function measured data on biokinetics is available only from a study performed on four children of different ages. In particular, renal scans are among the most frequent exams performed on infants and toddlers. Due to the young age, this patient group can be classified as a risk group with a higher probability of developing stochastic radiation effects compared to adults. As there are only limited data on biokinetics and dosimetry in this patient group, the aim of this study is to reassess the dosimetry and the associated radiation risk for a larger number of infants undergoing 99mTc-MAG3 renal scans based on a retrospective analysis of existing patient data. 
Data were collected retrospectively from 34 patients younger than 20 months with normal (20 patients) and abnormal renal function (14 patients) undergoing 99mTc-MAG3 scans. The patient-specific organ activity was estimated based on a retrospective calibration which was performed based on a set of two 3D-printed infant kidneys (newborns: 8.6 ml; 1-year-old: 23.4 ml) filled with known activities. Both phantoms were scanned at different positions along the anteroposterior axis inside a water phantom, providing depth- and size-dependent attenuation correction factors for planar imaging. Time-activity curves were determined by drawing kidney, bladder, and whole body regions-of-interest for each patient, and subsequently applying the calibration factor for conversion of counts to activity. Patient-specific time-integrated activity coefficients were obtained by integrating the organ-specific time-activity curves. Absorbed and effective dose coefficients for each patient were assessed with OLINDA/EXM for the provided newborn and 1-year-old phantom. Based on absorbed dose values, the radiation risk estimation was performed individually for each of the 34 patients with the National Cancer Institute’s Radiation Risk Assessment Tool.
The patients’ organ-specific mean absorbed dose coefficients for the patients with normal renal function were 0.04±0.03 mGy/MBq for the kidneys and 0.27±0.24 mGy/MBq for the bladder. This resulted in a mean effective dose coefficient of 0.02±0.02 mSv/MBq. Based on the dosimetry results, the evaluation of the excess lifetime risk (ELR) for the development of radiation-induced cancer showed that the group of newborns has an ELR of 16.8 per 100,000 persons, which is higher in comparison with the 1-year-old group with an ELR of 14.7 per 100,000 persons. With regard to the 14 patients with abnormal renal function, the mean values for the organ absorbed dose coefficients for the patients were: 0.40±0.34 mGy/MBq for the kidneys and 0.46±0.37 mGy/MBq for the bladder. The corresponding effective dose coefficients (mSv/MBq) was: 0.05±0.02 mSv/MBq. The mean ELR (per 100,000 persons) for developing cancer from radiation exposure for patients with abnormal renal function was 29.2±18.7 per 100,000 persons. 
As a result, the radiation-associated stochastic risk increases with the organ doses, taking age- and gender-specific influences into account. Overall, the lifetime radiation risk associated with the 99mTc-MAG3 scans is very low in comparison to the general population risk for developing cancer.
Furthermore, due to the increasing demand for PET-scans in children and adolescents with 68Ga-labelled peptides, in this work published data sets for those compounds were analyzed to derive recommendations for the administered activities in children and adolescents. The recommendation for the activities to be administered were based on the weight-independent effective dose model, proposed by the EANM Pediatric Dosage Card for application in pediatric nuclear medicine. The aim was to derive recommendations on administered activities for obtaining age-independent effective doses. Consequently, the corresponding weight-dependent effective dose coefficients were rescaled according to the formalism of the EANM dosage card, to determine the radiopharmaceutical class of 68Ga-labeled peptides (“multiples”), and to calculate the baseline activities based on the biokinetics of these compounds and an upper limit of the administered activity of 185 MBq for an adult. Analogous to 18F-fluoride, a minimum activity of 14 MBq is recommended. As a result, for those pediatric nuclear medicine applications involving 68Ga-labeled peptides, new values for the EANM dosage card were proposed and implemented based on the results derived in this work. 
Overall, despite the low additional radiation-related cancer risk, all efforts should be undertaken to optimize administered activities in children and adolescents for obtaining sufficient diagnostic information with minimal associated radiation risk.
N2  - Im Jahr 2006 wurden weltweit 0,18 Mio. nuklearmedizinische Diagnostikuntersuchungen bei Kindern durchgeführt. Für die meisten Radiopharmazeutika fehlen jedoch Daten zur Biokinetik und damit zur Dosimetrie oder diese wurden nicht öffentlich zugänglich gemacht. Daher basieren die meisten der heute vorgestellten Dosimetriedaten für Diagnostika bei Kindern und Jugendlichen auf den biokinetischen Daten von Erwachsenen. Selbst für eine der häufigsten nuklearmedizinischen Untersuchungen für diese Patientengruppe, die Nierenszintigraphie mit 99mTc-MAG3 für Bestimmung der Nierenfunktion, wurden Daten zur Biokinetik bisher nur für vier Kinder unterschiedlichen Alters erhoben. Insbesondere Nierenuntersuchungen gehören zu den häufigsten Untersuchungen bei Säuglingen und Kleinkindern. Aufgrund des jungen Alters kann diese Patientengruppe als Hochrisikogruppe mit einer höheren Wahrscheinlichkeit für das Eintreten stochastischer Strahlenwirkungen im Vergleich zu Erwachsenen eingestuft werden. Da es in dieser Patientengruppe nur begrenzte Daten zur Biokinetik und Dosimetrie gibt, ist das Ziel dieser Arbeit, die Dosimetrie und das damit verbundene Strahlenrisiko für eine größere Anzahl von Kleinkindern, die sich 99mTc-MAG3-Nierenscans unterziehen, auf der Grundlage einer retrospektiven Analyse bestehender Patientendaten neu zu bewerten. 
Die Daten wurden retrospektiv von 34 Patienten unter 20 Monaten mit normaler (20 Patienten) und eingeschränkter Nierenfunktion (14 Patienten) erhoben, bei denen 99mTc-MAG3-Scans durchgeführt wurden. Die patientenspezifische Organaktivität wurde basierend auf einer retrospektiven Kalibrierung abgeschätzt. Diese Kalibrierung basiert auf einem Satz von zwei 3D-gedruckten Säuglingsnieren, die mit bekannten Aktivitäten gefüllt wurden. Beide Phantome wurden an verschiedenen Positionen entlang der anteroposterioren Achse innerhalb eines Wasserphantoms gescannt und lieferten tiefen- und größenabhängige Schwächungskorrekturfaktoren für die planare Bildgebung. Die Zeit-Aktivitäts-Kurven wurden bestimmt, indem für jeden Patienten Nieren-, Blasen- und Ganzkörperregionen eingezeichnet und anschließend der entsprechende Kalibrierfaktor für die Umwandlung der Zählraten in Aktivität angewendet wurde. Patientenspezifische zeitintegrierte Aktivitätskoeffizienten wurden durch Integration der organspezifischen Zeit-Aktivitätskurven ermittelt. Die Energie- und effektiven Dosiskoeffizienten für jeden Patienten wurden mit OLINDA/EXM für das bereitgestellte Neugeborenen- und 1-Jahres-Phantom ermittelt. Basierend auf diesen Werten für die Energiedosen wurde eine individuelle Abschätzung des Strahlenrisikos für jeden der 34 Patienten mit dem Radiation Risk Assessment Tool des National Cancer Institute durchgeführt.
Die organspezifischen mittleren Energiedosiskoeffizienten der Patienten mit normaler Nierenfunktion lagen bei 0,04±0,03 mGy/MBq für die Nieren und 0,27±0,24 mGy/MBq für die Blase, was in einem mittleren effektiven Dosiskoeffizienten von 0,02±0,02 mSv/MBq resultiert. Basierend auf den  Ergebnissen der Dosimetrie, zeigte die Auswertung des zusätzlichen Lebenszeitrisikos ("excess lifetime risk", ELR) für die Entwicklung von strahleninduziertem Krebs, dass die Gruppe der Neugeborenen ein ELR von 16,8 pro 100.000 Personen aufweist, was höher ist als das der Gruppe der 1-jährigen mit 14,7 pro 100.000 Personen. Bei den 14 Patienten mit abnormaler Nierenfunktion waren die Mittelwerte für die Koeffizienten der organspezifischen Energiedosen für die Patienten: 0,40±0,34 mGy/MBq für die Nieren; 0,46±0,37 mGy/MBq für die Blase. Der effektivendosiskoeffizienten (mSv/MBq) waren: 0,05±0,02 mSv/MBq. Der mittlere ELR (pro 100.000 Personen) für die Entstehung von Krebs durch die Strahlenexposition von Patienten mit abnormaler Nierenfunktion betrug 29,2±18,7 pro 100.000 Personen. 
Das mit der Strahlung verbundene stochastische Risiko steigt mit den Organdosen unter Berücksichtigung alters- und geschlechtsspezifischer Einflüsse. Im Allgemeinen ist das mit den 99mTc-MAG3-Scans verbundene lebenslange Strahlenrisiko im Vergleich zum allgemeinen Bevölkerungsrisiko für die Entstehung von Krebs sehr gering.
Aufgrund der steigenden Nachfrage nach PET-Scans bei Kindern und Jugendlichen mit 68Ga-markierten Peptiden wurden zusätzlich publizierte Datensätze für diese Verbindungen analysiert, um Empfehlungen für zu verabreichende Aktivitäten bei Kindern und Jugendlichen abzuleiten. 
Die Dosisberechnungen dazu basierten auf dem Modell einer gewichtsunabhängigen effektiven Dosis, das von der EANM Pediatric Dosage Card für den Einsatz in der pädiatrischen Nuklearmedizin vorgeschlagen wurde. Ziel war es, Empfehlungen zu verabreichenden Aktivitäten so aufzuteilen, dass sich altersunabhängige effektive Dosen ergeben. Dazu wurden die entsprechenden gewichtsabhängigen effektiven Dosiskoeffizienten gemäß dem Formalismus der EANM-Dosierungsempfehlung neu berechnet, um die radiopharmazeutische Klasse der 68Ga-markierten Peptide ("Multiples") zu bestimmen und die Werte für Basisaktivität zu berechnen. Diese basierend auf den Biokinetiken dieser Verbindungen und einer Obergrenze der verabreichten Aktivität von 185 MBq für einen Erwachsenen. Analog zu 18F-Fluorid, wird eine Mindestaktivität von 14 MBq empfohlen. Darauf basierend wurden für die pädiatrischen nuklearmedizinischen Anwendungen mit 68Ga-markierten Peptiden neue Werte für die EANM-Dosierungsempfehlung vorgeschlagen. 
Insgesamt sollten, trotz des geringen zusätzlichen strahlenbedingten Krebsrisikos, alle Anstrengungen unternommen werden, um die verabreichten Aktivitäten bei Kindern und Jugendlichen zu optimieren, um ausreichende diagnostische Informationen bei minimalem zusätzlichem Strahlenrisiko zu erhalten.
KW  - Biokinetics
KW  - Absorbed Doses
KW  - Risk Assessment
KW  - Pediatric Patients
KW  - Dosimetry
KW  - Nuclear Medicine
KW  - Pediatric Nuclear Medicine
KW  - Diagnostic Imaging Exams
KW  - Radiation Protection
KW  - Administered Activities
KW  - Radiation-associated Cancer Risk
KW  - Ga-68-labelled Peptides
KW  - Tc-99m-MAG3 Scans
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-192640
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Bundschuh, Lena
A1  - Javadi, Mehrbod S.
A1  - Leal, Jeffrey P.
A1  - Higuchi, Takahiro
A1  - Pienta, Kenneth J.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - Interobserver Agreement for the Standardized Reporting System PSMA-RADS 1.0 on \(^{18}\)F-DCFPyL PET/CT Imaging
T2  - Journal of Nuclear Medicine
N2  - Objectives: Recently, the standardized reporting and data system for prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging studies, termed PSMA-RADS version 1.0, was introduced. We aimed to determine the interobserver agreement for applying PSMA-RADS to imaging interpretation of 18F-DCFPyL PET examinations in a prospective setting mimicking the typical clinical work-flow at a prostate cancer referral center. 
Methods: Four readers (two experienced readers (ER, > 3 years of PSMA-targeted PET interpretation experience) and two inexperienced readers (IR, < 1 year of experience)), who had all read the initial publication on PSMA-RADS 1.0, assessed 50 18F-DCFPyL PET/computed tomography (CT) studies independently. Per scan, a maximum of 5 target lesions were selected by the observers and a PSMA-RADS score for every target lesion was recorded. No specific pre-existing conditions were placed on the selection of the target lesions, although PSMA-RADS 1.0 suggests that readers focus on the most highly avid or largest lesions. An overall scan impression based on PSMA-RADS was indicated and interobserver agreement rates on a target lesion-based, on an organ-based, and on an overall PSMA-RADS score-based level were computed.
Results: The number of target lesions identified by each observer were as follows: ER 1, 123; ER 2, 134; IR 1, 123; and IR 2, 120. Among those selected target lesions, 125 were chosen by at least two individual observers (all four readers selected the same target lesion in 58/125 (46.4%) instances, three readers in 40/125 (32%) and two observers in 27/125 (21.6%) instances). The interobserver agreement for PSMA-RADS scoring among identical target lesions was good (intraclass correlation coefficient (ICC) for four, three and two identical target lesions, ≥0.60, respectively). For lymph nodes, an excellent interobserver agreement was derived (ICC=0.79). The interobserver agreement for an overall scan impression based on PSMA-RADS was also excellent (ICC=0.84), with a significant difference for ER (ICC=0.97) vs. IR (ICC=0.74, P=0.005).
Conclusions: PSMA-RADS demonstrates a high concordance rate in this study, even among readers with different levels of experience. This suggests that PSMA-RADS can be effectively used for communication with clinicians and can be implemented in the collection of data for large prospective trials.
KW  - 18F-DCFPyL
KW  - Positronen-Emissions-Tomografie
KW  - PSMA-RADS
KW  - interreader
KW  - interobserver
KW  - PSMA
KW  - prostate cancer
KW  - RADS
KW  - reporting and data system
KW  - PET
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167788
SN  - 0161-5505
N1  - This research was originally published in JNM. Rudolf A. Werner, Ralph A. Bundschuh, Lena Bundschuh, Mehrbod S. Javadi, Jeffrey P. Leal, Takahiro Higuchi, Kenneth J. Pienta, Andreas K. Buck, Martin G. Pomper, Michael A. Gorin, Constantin Lapa and Steven P. Rowe. Interobserver Agreement for the Standardized Reporting System PSMA-RADS 1.0 on 18F-DCFPyL PET/CT Imaging. J Nucl Med 2018;59:1857-1864 © SNMMI.
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Küsters, Sebastian
A1  - Al-Momani, Ehab
A1  - Marotta, Giorgio
A1  - Cosgrove, Kelly P.
A1  - van Dyck, Christopher H.
A1  - Herrmann, Ken
A1  - Homola, György A.
A1  - Pezzoli, Gianni
A1  - Buck, Andreas K.
A1  - Volkmann, Jens
A1  - Samnick, Samuel
A1  - Isaias, Ioannis U.
T1  - Cholinergic activity and levodopa-induced dyskinesia: a multitracer molecular imaging study
JF  - Annals of Clinical and Translational Neurology
N2  - Objective: To investigate the association between levodopa‐induced dyskinesias and striatal cholinergic activity in patients with Parkinson's disease.
Methods: This study included 13 Parkinson's disease patients with peak‐of‐dose levodopa‐induced dyskinesias, 12 nondyskinetic patients, and 12 healthy controls. Participants underwent 5‐[\(^{123}\)I]iodo‐3‐[2(S)‐2‐azetidinylmethoxy]pyridine single‐photon emission computed tomography, a marker of nicotinic acetylcholine receptors, [\(^{123}\)I]N‐ω‐fluoropropyl‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)nortropane single‐photon emission computed tomography, to measure dopamine reuptake transporter density and 2‐[\(^{18}\)F]fluoro‐2‐deoxyglucose positron emission tomography to assess regional cerebral metabolic activity. Striatal binding potentials, uptake values at basal ganglia structures, and correlations with clinical variables were analyzed.
Results: Density of nicotinic acetylcholine receptors in the caudate nucleus of dyskinetic subjects was similar to that of healthy controls and significantly higher to that of nondyskinetic patients, in particular, contralaterally to the clinically most affected side.
Interpretation: Our findings support the hypothesis that the expression of dyskinesia may be related to cholinergic neuronal excitability in a dopaminergic‐depleted striatum. Cholinergic signaling would play a role in maintaining striatal dopaminergic responsiveness, possibly defining disease phenotype and progression.
KW  - levodopa-induced dyskinesia
KW  - cholinergic activity
KW  - Parkinson’s disease
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170406
VL  - 4
IS  - 9
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Kircher, Stefan
A1  - Schirbel, Andreas
A1  - Rosenwald, Andreas
A1  - Kropf, Saskia
A1  - Pelzer, Theo
A1  - Walles, Thorsten
A1  - Buck, Andreas K.
A1  - Weber, Wolfgang A.
A1  - Wester, Hans-Juergen
A1  - Herrmann, Ken
A1  - Lückerath, Katharina
T1  - Targeting CXCR4 with [\(^{68}\)Ga]Pentixafor: a suitable theranostic approach in pleural mesothelioma?
JF  - Oncotarget
N2  - C-X-C motif chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. This study investigated the feasibility of CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using [\(^{68}\)Ga]Pentixafor in malignant pleural mesothelioma.

Six patients with pleural mesothelioma underwent [\(^{68}\)Ga]Pentixafor-PET/CT. 2′-[\(^{18}\)F]fluoro-2′-deoxy-D-glucose ([\(^{18}\)F]FDG)-PET/CT (4/6 patients) and immunohistochemistry obtained from biopsy or surgery (all) served as standards of reference. Additionally, 9 surgical mesothelioma samples were available for histological work-up.

Whereas [\(^{18}\)F]FDG-PET depicted active lesions in all patients, [\(^{68}\)Ga]Pentixafor-PET/CT recorded physiologic tracer distribution and none of the 6 patients presented [\(^{68}\)Ga]Pentixafor-positive lesions. This finding paralleled results of immunohistochemistry which also could not identify relevant CXCR4 surface expression in the samples analyzed.

In contrast to past reports, our data suggest widely absence of CXCR4 expression in pleural mesothelioma. Hence, robust cell surface expression should be confirmed prior to targeting this chemokine receptor for diagnosis and/or therapy.
KW  - PET
KW  - CXCR4
KW  - [\(^{68}\)Ga] pentixafor
KW  - pleural mesothelioma
KW  - theranostics
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169989
VL  - 8
IS  - 57
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Lückerath, Katharina
A1  - Kleinlein, Irene
A1  - Monoranu, Camelia Maria
A1  - Linsenmann, Thomas
A1  - Kessler, Almuth F.
A1  - Rudelius, Martina
A1  - Kropf, Saskia
A1  - Buck, Andreas K.
A1  - Ernestus, Ralf-Ingo
A1  - Wester, Hans-Jürgen
A1  - Löhr, Mario
A1  - Herrmann, Ken
T1  - \(^{68}\)Ga-Pentixafor-PET/CT for Imaging of Chemokine Receptor 4 Expression in Glioblastoma
JF  - Theranostics
N2  - Chemokine receptor-4 (CXCR4) has been reported to be overexpressed in glioblastoma (GBM) and to be associated with poor survival. This study investigated the feasibility of non-invasive CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using the radiolabelled chemokine receptor ligand \(^{68}\)Ga-Pentixafor.
15 patients with clinical suspicion on primary or recurrent glioblastoma (13 primary, 2 recurrent tumors) underwent \(^{68}\)Ga-Pentixafor-PET/CT for assessment of CXCR4 expression prior to surgery. O-(2-\(^{18}\)F-fluoroethyl)-L-tyrosine (\(^{18}\)F-FET) PET/CT images were available in 11/15 cases and were compared visually and semi-quantitatively (SUV\(_{max}\), SUV\(_{mean}\)). Tumor-to-background ratios (TBR) were calculated for both PET probes. \(^{68}\)Ga-Pentixafor-PET/CT results were also compared to histological CXCR4 expression on neuronavigated surgical samples.
\(^{68}\)Ga-Pentixafor-PET/CT was visually positive in 13/15 cases with SUV\(_{mean}\) and SUV\(_{max}\) of 3.0±1.5 and 3.9±2.0 respectively. Respective values for \(^{18}\)F-FET were 4.4±2.0 (SUV\(_{mean}\)) and 5.3±2.3 (SUV\(_{max}\)). TBR for SUV\(_{mean}\) and SUV\(_{max}\) were higher for \(^{68}\)Ga-Pentixafor than for \(^{18}\)F-FET (SUV\(_{mean}\) 154.0±90.7 vs. 4.1±1.3; SUV\(_{max}\) 70.3±44.0 and 3.8±1.2, p<0.01), respectively. Histological analysis confirmed CXCR4 expression in tumor areas with high \(^{68}\)Ga-Pentixafor uptake; regions of the same tumor without apparent \(^{68}\)Ga-Pentixafor uptake showed no or low receptor expression.
In this pilot study, \(^{68}\)Ga-Pentixafor retention has been observed in the vast majority of glioblastoma lesions and served as readout for non-invasive determination of CXCR4 expression. Given the paramount importance of the CXCR4/SDF-1 axis in tumor biology, \(^{68}\)Ga-Pentixafor-PET/CT might prove a useful tool for sensitive, non-invasive in-vivo quantification of CXCR4 as well as selection of patients who might benefit from CXCR4-directed therapy.
KW  - imaging
KW  - chemokine receptor-4
KW  - glioblastoma
KW  - positron emission tomography/computed tomography
KW  - \(^{68}\)Ga-Pentixafor
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168174
VL  - 6
IS  - 3
ER  - 
TY  - THES
A1  - Brumberg [geb. Ichouh], Dalma
T1  - \(^{11}\)C-MET und \(^{18}\)F-FDG: \(In\) \(vitro\) Vergleich zur Bildgebung beim Multiplen Myelom im Kontext biologischer Charakteristika
T1  - Imaging multiple myeloma with \(^{11}\)C-MET and \(^{18}\)F-FDG: \(In\) \(vitro\) comparison in the context of biological characteristics
N2  - Das Multiple Myelom ist eine hämatologische Erkrankung, die durch die Proliferation von Plasmazellen und die Produktion von Antikörpern oder deren Leichtketten gekennzeichnet ist. Eine frühe Diagnosestellung durch Detektion sowohl intra- als auch extramedullärer Manifestationen ist für die Einleitung einer effektiven Therapie von entscheidender Bedeutung. Ebenso bedeutsam ist ein wirksames Therapiemonitoring. Wichtige diagnostische Modalitäten sind bei beiden Fragestellungen tomografische, bildgebende Verfahren. Hierbei wurde die Effektivität der 18F-FDG-PET/CT im Rahmen der Diagnose, des Stagings und der Prognoseabschätzung bereits nachgewiesen. Dennoch ist ihr klinischer Nutzen durch die geringe Sensitivität bei Detektion von diffusem Knochenmarksbefall und Vorliegen sowohl falsch positiver als auch falsch negativer Befunde limitiert. 
Die vorliegende Arbeit hat untersucht, ob der aminosäurebasierte Tracer 11C-MET über spezifische Eigenschaften verfügt, die eine höhere Sensitivität und Spezifität in der Detektion von Myelomzellen ermöglichen und ob der Radioligand dem etablierten Glukoseanalogon 18F-FDG überlegen ist. Hierfür wurden drei etablierte humane Myelomzelllinien, sowohl nativ als auch nach 48-stündiger Therapie mit dem Proteasominhibitor Carfilzomib, mit 18F-FDG und 11C-MET inkubiert und mithilfe eines Gammastrahlungszählers beurteilt. Zudem wurde untersucht, ob die Traceraufnahme mit spezifischen Charakteristika der Tumorbiologie korreliert. So wurde die Oberflächenexpression von CD138 und CXCR4, die intrazelluläre Expression der Leichtketten κ/λ und die Proliferation der Zelllinien mittels Durchflusszytometrie vor und nach Behandlung mit Carfilzomib eruiert.
Die unbehandelten Zellen zeigten, verglichen zu 18F-FDG, bereits nach kürzester Inkubationsdauer eine 3-3,5-fach höhere 11C-MET Retention. Weiterhin zeigte sich die 11C-MET-Aufnahme nach Behandlung aller Zellreihen insgesamt marginal höher als die 18F-FDG-Aufnahme, während die Reduktion der 11C-MET-Anreicherung im prä- zu posttherapeutischen Vergleich für alle drei Zelllinien signifikant war.
Eine mögliche Erklärung für diese Beobachtungen liefert die Myelombiologie: eine erhöhte Aufnahme der radioaktiv markierten Aminosäure durch MM-Zellen könnte durch eine Zunahme der Zellproliferation und insbesondere durch eine Steigerung der Proteinsynthese im Rahmen der überschießenden Produktion von M-Protein bedingt sein. In Zusammenschau könnte 11C-MET mit höherer Sensitivität Myelommanifestationen detektieren, wodurch ggf. Läsionen mit geringem Metabolismus dargestellt und eine bessere Beurteilung des Krankheitspogresses erfolgen könnte.  Zudem bietet für den klinischen Einsatz die – verglichen zu 18F-FDG – größere Differenz der 11C-MET-Retention zwischen prä- und posttherapeutischer Messung die Möglichkeit einer besseren Beurteilbarkeit des Therapieansprechens. 11C-MET birgt ggf. das Potential auch minimale aktive Restherde zu detektieren und damit Patienten einem individualisierten Therapiekonzept zuzuführen.
Ein Zusammenhang zwischen den untersuchten Biomarkern und der 11C-MET Retention bzw. deren Abnahme nach Behandlung konnte nicht gezeigt werden. Somit sollten für 11C-MET andere Biomarker herangezogen werden, um diese mit der Bildgebung zu korrelieren und zu bewerten.
N2  - Multiple myeloma is a heterogeneous lymphoproliferative disease, which is characterized by an uncontrolled proliferation of clonal plasma cells. It is both essential to diagnose the disease at an early stage in order to prevent organ damage and to monitor therapy to adjust and individualize it. Imaging modalities like 18F-FDG-PET/CT play an important role for these purposes. However, its clinical benefit is limited due to the low detection rate of diffuse bone marrow invasion and false positive or negative findings. To overcome these limitations, we analysed if the amino acid-based tracer 11C-MET has specific features to reach a higher sensitivity and specificity in detecting myeloma cells. Therefore, three established human myeloma cell lines were incubated with 18F-FDG and 11C-MET natively without and after therapy with the proteasome inhibitor Carfilzomib and evaluated via gamma counter. The results showed a higher 11C-MET-uptake in untreated cells after a short time, a higher uptake after treatment with Carfilzomib and a significant reduction pre- to post therapy compared to 18F-FDG. These results assume that 11C-MET has the potential to be more sensitive in detecting myeloma manifestations as well as for the monitoring of disease activity during and after treatment. Furthermore, it might also have the potential to visualize minimal residual disease after treatment. This could lead to an early adaption of therapy and thereby may extend progression free survival. 
This study also investigated the relationship between specific biological characteristics of multiple myeloma (surface expression of CD138 and CXCR4, intracellular light chain production and proliferation rate) and radioligand uptake. A correlation between the markers and the uptake could not be proven, so that we assume that other biomarkers should be considered and correlated with 11C-MET to reflect tumor biology and verify possible prognostic markers.
KW  - Multiples Myelom
KW  - 11C-Methionin
KW  - Positronenemissionstomographie
KW  - 18F-FDG
KW  - CD138
KW  - CXCR4
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-181843
ER  - 
TY  - INPR
A1  - Yin, Yafu
A1  - Werner, Rudolf A.
A1  - Higuchi, Takahiro
A1  - Lapa, Constantin
A1  - Pienta, Kenneth J.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Rowe, Steven P.
T1  - Follow-Up of Lesions with Equivocal Radiotracer Uptake on PSMA-Targeted PET in Patients with Prostate Cancer: Predictive Values of the PSMA-RADS-3A and PSMARADS- 3B Categories
T2  - Journal of Nuclear Medicine
N2  - Purpose: Prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging has become commonly utilized in patients with prostate cancer (PCa). The PSMA reporting and data system version 1.0 (PSMA-RADS version 1.0) categorizes lesions on the basis of the likelihood of PCa involvement, with PSMA-RADS-3A (soft tissue) and PSMA-RADS-3B (bone) lesions being indeterminate for the presence of disease. We retrospectively reviewed the imaging follow-up of such lesions to determine the rate at which they underwent changes suggestive of underlying PCa.
Methods: PET/CT imaging with \(^{18}\)F-DCFPyL was carried out in 110 patients with PCa and lesions were categorized according to PSMA-RADS Version 1.0. 56/110 (50.9%) patients were determined to have indeterminate PSMA-RADS-3A or PSMA-RADS-3B lesions and 22/56 (39.3%) patients had adequate follow-up to be included in the analysis. The maximum standardized uptake values (SUV\(_{max}\)) of the lesions were obtained and the ratios of SUV\(_{max}\) of the lesions to SUV\(_{mean}\) of blood pool (SUV\(_{max}\)-lesion/SUV\(_{mean}\)-bloodpool) were calculated. Pre-determined criteria were used to evaluate the PSMA-RADS-3A and PSMA-RADS-3B lesions on follow-up imaging to determine if they demonstrated evidence of underlying malignancy.
Results: A total of 46 lesions in 22 patients were considered indeterminate for PCa (i.e. PSMA-RADS-3A (32 lesions) or PSMA-RADS-3B (14 lesions)) and were evaluable on follow-up imaging. 27/46 (58.7%) lesions demonstrated changes on follow-up imaging consistent with the presence of underlying PCa at baseline. These lesions included 24/32 (75.0%) PSMA-RADS-3A lesions and 3/14 (21.4%) lesions categorized as PSMA-RADS-3B. The ranges of SUVmax and SUVmax-lesion/SUVmean-bloodpool overlapped between those lesions demonstrating changes consistent with malignancy on follow-up imaging and those lesions that remained unchanged on follow-up.
Conclusion: PSMA-RADS-3A and PSMA-RADS-3B lesions are truly indeterminate in that proportions of findings in both categories demonstrate evidence of malignancy on follow-up imaging. Overall, PSMA-RADS-3A lesions are more likely than PSMA-RADS-3B lesions to represent sites of PCa and this information should be taken into when guiding patient therapy.
KW  - PSMA-RADS-3B
KW  - Positronen-Emissions-Tomografie
KW  - prostate-specific membrane antigen
KW  - prostate cancer
KW  - PSMA-targeted PET
KW  - PSMA-RADS-3A
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167594
SN  - 0161-5505
N1  - This research was originally published in JNM. Yafu Yin, Rudolf A. Werner, Takahiro Higuchi, Constantin Lapa, Kenneth J. Pienta, Martin G. Pomper, Michael A. Gorin, Steven P. Rowe.
Follow-Up of Lesions with Equivocal Radiotracer Uptake on PSMA-Targeted PET in Patients with Prostate Cancer: Predictive Values of the PSMA-RADS-3A and PSMA-RADS-3B Categories. J Nucl Med. 2019;60:511-516 © SNMMI.
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Ordonez, Alvaro A.
A1  - Sanchez-Bautista, Julian
A1  - Marcus, Charles
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
A1  - Pomper, Martin G.
A1  - Leal, Jeffrey P.
A1  - Lodge, Martin A.
A1  - Javadi, Mehrbod S.
A1  - Jain, Sanjay K.
A1  - Higuchi, Takahiro
T1  - Novel functional renal PET imaging with 18F-FDS in human subjects
JF  - Clinical Nuclear Medicine
N2  - The novel PET probe 2-deoxy-2-18F-fluoro-D-sorbitol (18F-FDS) has demonstrated favorable renal kinetics in animals. We aimed to elucidate its imaging properties in two human volunteers. 18F-FDS was produced by a simple one-step reduction from 18F-FDG. On dynamic renal PET, the cortex was delineated and activity gradually transited in the parenchyma, followed by radiotracer excretion. No adverse effects were reported. Given the higher spatiotemporal resolution of PET relative to conventional scintigraphy, 18F-FDS PET offers a more thorough evaluation of human renal kinetics. Due to its simple production from 18F-FDG, 18F-FDS is virtually available at any PET facility with radiochemistry infrastructure.
KW  - 2-deoxy-2-18F-fluoro-D-sorbitol
KW  - Positronen-Emissions-Tomografie
KW  - 18F-FDS
KW  - renal imaging
KW  - Positron-Emission Tomography
KW  - split renal function
KW  - kidney
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174634
SN  - 0363-9762
VL  - 44
IS  - 5
ER  - 
TY  - THES
A1  - Kajdi, Georg Wilhelm
T1  - iROLL - 3D-bildnavigierte, radioaktivitätsgestützte Resektion des nicht-palpablen Mammakarzinoms
T1  - iROLL - image-radioguided occult lesion localization in breast cancer
N2  - In dieser prospektiven Studie wurde die Durchführbarkeit der 3D-bildnavigierten, radioaktivitätsgestützten Resektion des nicht-palpablen Mammakarzinoms (iROLL) unter Verwendung der freehand SPECT (fhSPECT)-Technologie untersucht. Das Verfahren wurde mit der als Goldstandard etablierten, drahtgestützten Lokalisation (WGL) verglichen. Sekundäre Endpunkte der Studie waren die erfolgreiche Sentinellymphknotenbiopsie (SLNB) mittels fhSPECT, der Patientenkomfort beider Verfahren, die mögliche Vorhersage tumorpositiver Resektatränder mittels fhSPECT, inklusive notwendiger Nachresektionen und der Einfluss von iROLL auf die OP-Dauer.
Die fhSPECT-gestützte iROLL ist ein schmerzarmes, patientenfreundliches, zeiteffizientes und v.a. gut durchführbares brusterhaltendes Therapieverfahren (BET) ist. Gegenüber der WGL wird eine einzeitige Markierung zur Primarius- und SLN-Markierung möglich, ohne dabei auf eine visuell fassbare, intraoperative Navigationshilfe verzichten zu müssen.
N2  - In this prospective pilot study the feasability of iROLL (image-radioguided occult lesion localization in breast cancer)was investigated and compared to the gold standard of wire-guided localization (WGL). Secondary end-points were the sucessfull sentinel lymph node biopsy (SLNB) with the fhSPECT technology, evaluation of patient comfort and the possible prediction of tumor-positive resection margins with fhSPECT. Additional resections due to positive fhSPECT-scans and influence an operation time were also evaluated. fhSPECT-guided iROLL is a less painful, patient-friendly, time efficient and easily feasible therapy regimen for breast conserving surgery (BET). Compared to WGL it enables a one-time tracer-application for tumor and SLN detection while maintaining a visual component for intraoperative navigation.
KW  - Brustkrebs
KW  - Lymphknoten
KW  - Gammaspektrometer
KW  - iROLL
KW  - fhSPECT
KW  - 3D-Bildnavigation
KW  - Mammakarzinom
KW  - SLNB
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-180459
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Bundschuh, Lena
A1  - Fanti, Stefano
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Weich, A.
A1  - Pienta, Kenneth J.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Herrmann, Ken
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - Novel Structured Reporting Systems for Theranostic Radiotracers
T2  - Journal of Nuclear Medicine
N2  - Standardized reporting is more and more routinely implemented in clinical practice and such structured reports have a major impact on a large variety of medical fields, e.g. laboratory medicine, pathology, and, recently, radiology. Notably, the field of nuclear medicine is constantly evolving, as novel radiotracers for numerous clinical applications are developed. Thus, framework systems for standardized reporting in this field may a) increase clinical acceptance of new radiotracers, b) allow for inter- and intra-center comparisons for quality assurance, and c) may be used in (global) multi-center studies to ensure comparable results and enable efficient data abstraction. In the last two years, several standardized framework systems for positron emission tomography (PET) radiotracers with potential theranostic applications have been proposed. These include systems for prostate-specific membrane antigen (PSMA)-targeted PET agents for the diagnosis and treatment of prostate cancer (PCa) and somatostatin receptor (SSTR)-targeted PET agents for the diagnosis and treatment of neuroendocrine neoplasias. In the present review, those standardized framework systems for PSMA- and SSTR-targeted PET will be briefly introduced followed by an overview of their advantages and limitations. In addition, potential applications will be defined, approaches to validate such concepts will be proposed, and future perspectives will be discussed.
KW  - standardized reporting
KW  - Positronen-Emissions-Tomografie
KW  - prostate cancer
KW  - neuroendocrine neoplasia
KW  - 68Ga-DOTATATE
KW  - 68Ga-DOTATOC
KW  - 68Ga-DOTANOC
KW  - somatostatin receptor
KW  - SSTR
KW  - prostate-specific membrane antigen
KW  - PSMA
KW  - RADS
KW  - PSMA-RADS
KW  - SSTR-RADS
KW  - MI-RADS
KW  - PROMISE
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174629
SN  - 0161-5505
N1  - This research was originally published in JNM. Authors: Rudolf A. Werner, Ralph A. Bundschuh, Lena Bundschuh, Stefano Fanti, Mehrbod S. Javadi, Takahiro Higuchi, A. Weich, Kenneth J. Pienta, Andreas K. Buck, Martin G. Pomper, Michael A. Gorin, Ken Herrmann, Constantin Lapa, Steven P. Rowe. Novel Structured Reporting Systems for Theranostic Radiotracers. J Nucl Med May 1, 2019 vol. 60 no. 5 577-584 © SNMMI.
ER  - 
TY  - JOUR
A1  - Beykan, Seval
A1  - Fani, Melpomeni
A1  - Jensen, Svend Borup
A1  - Nicolas, Guillaume
A1  - Wild, Damian
A1  - Kaufmann, Jens
A1  - Lassmann, Michael
T1  - In vivo biokinetics of \(^{177}\)Lu-OPS201 in Mice and Pigs as a Model for Predicting Human Dosimetry
JF  - Contrast Media & Molecular Imaging
N2  - Introduction. \(^{177}\)Lu-OPS201 is a high-affinity somatostatin receptor subtype 2 antagonist for PRRT in patients with neuroendocrine tumors. The aim is to find the optimal scaling for dosimetry and to compare the biokinetics of \(^{177}\)Lu-OPS201 in animals and humans. Methods. Data on biokinetics of \(^{177}\)Lu-OPS201 were analyzed in athymic nude Foxn1\(^{nu}\) mice (28 F, weight: 26 ± 1 g), Danish Landrace pigs (3 F-1 M, weight: 28 ± 2 kg), and patients (3 F-1 M, weight: 61 ± 17 kg) with administered activities of 0.19–0.27 MBq (mice), 97–113 MBq (pigs), and 850–1086 MBq (patients). After euthanizing mice (up to 168 h), the organ-specific activity contents (including blood) were measured. Multiple planar and SPECT/CT scans were performed until 250 h (pigs) and 72 h (patients) to quantify the uptake in the kidneys and liver. Blood samples were taken up to 23 h (patients) and 300 h (pigs). In pigs and patients, kidney protection was applied. Time-dependent uptake data sets were created for each species and organ/tissue. Biexponential fits were applied to compare the biokinetics in the kidneys, liver, and blood of each species. The time-integrated activity coefficients (TIACs) were calculated by using NUKFIT. To determine the optimal scaling, several methods (relative mass scaling, time scaling, combined mass and time scaling, and allometric scaling) were compared. Results. A fast blood clearance of the compound was observed in the first phase (<56 h) for all species. In comparison with patients, pigs showed higher liver retention. Based on the direct comparison of the TIACs, an underestimation in mice (liver and kidneys) and an overestimation in pigs’ kidneys compared to the patient data (kidney TIAC: mice = 1.4 h, pigs = 7.7 h, and patients = 5.8 h; liver TIAC: mice = 0.7 h, pigs = 4.1 h, and patients = 5.3 h) were observed. Most similar TIACs were obtained by applying time scaling (mice) and combined scaling (pigs) (kidney TIAC: mice = 3.9 h, pigs = 4.8 h, and patients = 5.8 h; liver TIAC: mice = 0.9 h, pigs = 4.7 h, and patients = 5.3 h). Conclusion. If the organ mass ratios between the species are high, the combined mass and time scaling method is optimal to minimize the interspecies differences. The analysis of the fit functions and the TIACs shows that pigs are better mimicking human biokinetics.
KW  - medicine
KW  - neuroendocrine tumors
KW  - biokinetics
KW  - \(^{177}\)Lu-OPS201
KW  - dosimetry
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177382
VL  - 2019
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Marcus, Charles
A1  - Sheikhbahaei, Sara
A1  - Solnes, Lilja B.
A1  - Leal, Jeffrey P.
A1  - Du, Yong
A1  - Rowe, Steven P.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
T1  - Visual and Semiquantitative Accuracy in Clinical Baseline 123I-Ioflupane SPECT/CT Imaging
JF  - Clinical Nuclear Medicine
N2  - PURPOSE:
We aimed to (a) elucidate the concordance of visual assessment of an initial I-ioflupane scan by a human interpreter with comparison to results using a fully automatic semiquantitative method and (b) to assess the accuracy compared to follow-up (f/u) diagnosis established by movement disorder specialists.

METHODS:
An initial I-ioflupane scan was performed in 382 patients with clinically uncertain Parkinsonian syndrome. An experienced reader performed a visual evaluation of all scans independently. The findings of the visual read were compared with semiquantitative evaluation. In addition, available f/u clinical diagnosis (serving as a reference standard) was compared with results of the human read and the software.

RESULTS:
When comparing the semiquantitative method with the visual assessment, discordance could be found in 25 (6.5%) of 382 of the cases for the experienced reader (ĸ = 0.868). The human observer indicated region of interest misalignment as the main reason for discordance. With neurology f/u serving as reference, the results of the reader revealed a slightly higher accuracy rate (87.7%, ĸ = 0.75) compared to semiquantification (86.2%, ĸ = 0.719, P < 0.001, respectively). No significant difference in the diagnostic performance of the visual read versus software-based assessment was found.

CONCLUSIONS:
In comparison with a fully automatic semiquantitative method in I-ioflupane interpretation, human assessment obtained an almost perfect agreement rate. However, compared to clinical established diagnosis serving as a reference, visual read seemed to be slightly more accurate as a solely software-based quantitative assessment.
KW  - Single-Photon-Emissions-Computertomographie
KW  - SPECT
KW  - Parkinson’s disease
KW  - Parkinsonism
KW  - DaTscan
KW  - 123I-Ioflupane
KW  - SPECT
KW  - SPECT/CT
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168181
SN  - 1536-0229
VL  - 44
IS  - 1
ER  - 
TY  - JOUR
A1  - Eberlein, Uta
A1  - Bröer, Jörn Hendrik
A1  - Vandevoorde, Charlot
A1  - Santos, Paula
A1  - Bardiès, Manuel
A1  - Bacher, Klaus
A1  - Nosske, Dietmar
A1  - Lassmann, Michael
T1  - Biokinetics and dosimetry of commonly used radiopharmaceuticals in diagnostic nuclear medicine – a review
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Purpose

The impact on patients’ health of radiopharmaceuticals in nuclear medicine diagnostics has not until now been evaluated systematically in a European context. Therefore, as part of the EU-funded Project PEDDOSE.NET (www.​peddose.​net), we review and summarize the current knowledge on biokinetics and dosimetry of commonly used diagnostic radiopharmaceuticals.

Methods

A detailed literature search on published biokinetic and dosimetric data was performed mostly via PubMed (www.​ncbi.​nlm.​nih.​gov/​pubmed). In principle the criteria for inclusion of data followed the EANM Dosimetry Committee guidance document on good clinical reporting.

Results

Data on dosimetry and biokinetics can be difficult to find, are scattered in various journals and, especially in paediatric nuclear medicine, are very scarce. The data collection and calculation methods vary with respect to the time-points, bladder voiding, dose assessment after the last data point and the way the effective dose was calculated. In many studies the number of subjects included for obtaining biokinetic and dosimetry data was fewer than ten, and some of the biokinetic data were acquired more than 20 years ago.

Conclusion

It would be of interest to generate new data on biokinetics and dosimetry in diagnostic nuclear medicine using state-of-the-art equipment and more uniform dosimetry protocols. For easier public access to dosimetry data for diagnostic radiopharmaceuticals, a database containing these data should be created and maintained.
KW  - Dosimetry
KW  - Biokinetics
KW  - Diagnostic radiopharmaceuticals
KW  - Effective dose
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133846
VL  - 38
IS  - 12
ER  - 
TY  - THES
A1  - Hartrampf, Philipp Emanuel
T1  - Evaluation der PET-Tracer [\(^1\)\(^8\)F]FDG, [\(^1\)\(^8\)F]Cholin und [\(^6\)\(^8\)Ga]PSMA I&T zur nicht-invasiven Charakterisierung von Prostatakarzinomzellen und des Ansprechens auf eine Docetaxeltherapie
T1  - Evaluation of PET tracers [\(^1\)\(^8\)F]FDG, [\(^1\)\(^8\)F]choline and [\(^6\)\(^8\)Ga]PSMA I&T for non-invasive characterization of prostate cancer cells and response to docetaxel therapy
N2  - Das Prostatakarzinom (PCa) stellt derzeit in Deutschland die häufigste Krebserkrankung der männlichen Bevölkerung dar und steht bei den tödlich verlaufenden Malignomen an zweiter Stelle. Aktuell umfasst die Diagnostik immer öfter auch eine molekulare Bildgebung mittels PET/CT und den Tracern [18F]Cholin und [68Ga]PSMA. Letzterer detektiert selektiv das prostataspezifische Membranantigen (PSMA), welches in Prostatakarzinomzellen häufig überexprimiert ist. Das Wachstum von PCa geschieht in der Regel androgenabhängig, wobei sich auch teilweise eine androgenunabhängige Entwicklung findet. Für das bei kastrationsresistenten Karzinomen und fortgeschrittenen Stadien eingesetzte Chemotherapeutikum Docetaxel, werden immer wieder Resistenzentwicklungen beobachtet, wodurch dieses nur unzureichend effektiv ist. Ziel dieser Arbeit war es, die Eignung verschiedener PET-Tracer ([18F]FDG, [18F]Cholin und [68Ga]PSMA) zur Bildgebung androgenabhängiger und -unabhängiger Prostatakarzinomzellen zu testen sowie ihr Potential zur Beurteilung des Therapieansprechens auf Docetaxel zu untersuchen. Weiterhin sollte untersucht werden, ob die [68Ga]PSMA-Retention mit der PSMA-Expression korreliert. Im zweiten Teil wurde ein Zusammenhang zwischen der Expression von PSMA und der Resistenzentwicklung gegen Docetaxel untersucht.
Methoden: Für die in-vitro Experimente wurden die hormonabhängige Zelllinie LNCaP sowie die hormonunabhängige Zelllinie LNCaP C4-2 verwendet. Im zweiten Teil wurden zusätzlich PSMA-negative PC-3 Zellen eingesetzt. Die aufgenommene bzw. gebundene Traceraktivität wurde mittels Gammacounter gemessen. Die Untersuchung der PSMA-Expression erfolgte mit Western-Blot und Durchflusszytometrie. Ein PSMA-Knockdown-System wurde mittels siRNA in LNCaP-Zellen etabliert.
Ergebnisse: Die PSMA-Expression und die Sensitivität gegenüber Docetaxel waren bei LNCaP Zellen tendenziell erhöht gegenüber der LNCaP C4-2 Zelllinie. Nach Docetaxelbehandlung zeigte sich in beiden Zellreihen eine unveränderte PSMA-Expression. Der PSMA-spezifische PET-Tracer zeigte, im Vergleich zu den metabolischen Tracern [18F]FDG und [18F]Cholin, eine nur sehr geringe Retention. Im Vergleich der Zelllinien untereinander nahmen LNCaP C4-2 Zellen ca. 50 % mehr [18F]FDG auf als LNCaP Zellen. Die Aufnahme von [18F]Cholin unterschied sich nicht signifikant. Der Tracer [68Ga]PSMA zeigte eine höhere Bindung an LNCaP Zellen im Vergleich zu LNCaP C4-2 Zellen. In weiteren Versuchen konnte gezeigt werden, dass sowohl [18F]FDG als auch [18F]Cholin, nicht jedoch [68Ga]PSMA in vitro ein Therapieansprechen auf Docetaxel durch verminderte Traceraufnahme in beiden Zelllinien aufzeigen. Es konnte zudem eine direkte Korrelation zwischen der [68Ga]PSMA-Bindung und der PSMA-Expression nachgewiesen werden.
Nach einer siRNA-vermittelten Verminderung der PSMA-Expression in LNCaP Zellen (Knockdown-Zellen) zeigte sich eine deutlich geringere Sensitivität für Docetaxel. Gleichzeitig war jedoch die Docetaxelsensitivität von PSMA-negativen PC-3 Zellen höher als die von LNCaP Knockdown-Zellen. 
Schlussfolgerung: Insgesamt zeigten unsere Untersuchungen, dass sich die PET-Tracer [18F]FDG und [68Ga]PSMA zur Unterscheidung des androgenabhängigen Zellmodells vom androgenunabhängigen Modell eignen. Außerdem ermöglicht der [68Ga]PSMA-Tracer eine Einschätzung der PSMA-Expression. Die Tracer [18F]FDG und [18F]Cholin eignen sich in vitro für die Beurteilung des Therapieansprechens einer Docetaxeltherapie, [68Ga]PSMA dagegen nicht. Die PSMA-Expression scheint ein entscheidender, aber nicht alleinstehender Faktor für die Sensitivität von LNCaP Zellen gegenüber Docetaxel zu sein. Es scheinen hierbei allerdings eher der Verlust von PSMA, wie im Knockdown-Modell induziert, sowie bislang unbekannte Faktoren eine wichtige Rolle zu spielen.
N2  - Prostate carcinoma (PCa) is currently the most frequent cancer in men in Germany and is the second leading cause of cancer deaths. Currently, diagnostics more and more often include molecular imaging using PET/CT and the tracers [18F]choline and [68Ga]PSMA. The latter selectively detects the prostate-specific membrane antigen (PSMA), which is often overexpressed in prostate cancer cells. The growth of PCa is usually androgen-dependent, although it is sometimes also developing independently of androgen. For the chemotherapeutic agent docetaxel, which is used for castration-resistant carcinomas and advanced stages, the development of resistance is observed again and again, resulting in insufficient efficacy. The aim of this work was to evaluate the potential of different PET tracers ([18F]FDG, [18F]Choline and [68Ga]PSMA) for the imaging of androgen-dependent and independent prostate carcinoma cells as well as their potential for the assessment of therapy response to docetaxel. Furthermore, it should be investigated whether [68Ga]PSMA uptake correlates with PSMA expression. In the second part, an association between the expression of PSMA and the development of resistance to docetaxel was investigated. 
Methods: For the in vitro experiments the hormone-dependent cell line LNCaP and the hormone-independent cell line LNCaP C4-2 were used. In the second part PSMA-negative PC-3 cells were additionally used. The tracer uptake and binding activity was measured by gamma counter. PSMA expression was determined by Western blot and flow cytometry. A PSMA knockdown system was established in LNCaP cells using siRNA. 
Results: PSMA expression and sensitivity to docetaxel were increased in LNCaP cells compared to the LNCaP C4-2 cells. After docetaxel treatment, both cell lines showed unchanged PSMA expression. Compared to the metabolic tracers [18F]FDG and [18F]choline, the PSMA-specific PET tracer showed very low uptake. In comparison of the cell lines, LNCaP C4-2 cells took up about 50 % more [18F]FDG than LNCaP cells. The uptake of [18F]choline did not differ significantly. The tracer [68Ga]PSMA showed a higher binding to LNCaP cells compared to LNCaP C4-2 cells. In further experiments it was observed that both [18F]FDG and [18F]choline, but not [68Ga]PSMA, in vitro showed a therapy response to docetaxel by reduced tracer uptake in both cell lines. A direct correlation between [68Ga]PSMA binding and PSMA expression was also found.
After a siRNA-mediated reduction of PSMA expression in LNCaP cells (knockdown cells), a significantly lower sensitivity for docetaxel was observed. At the same time, however, the docetaxel sensitivity of PSMA-negative PC-3 cells was higher than that of LNCaP knockdown cells. 
Conclusion: Overall, our investigations showed that the PET tracers [18F]FDG and [68Ga]PSMA are suitable for differentiating the androgen-dependent cell model from the androgen-independent model.  In addition, the [68Ga]PSMA tracer allows an assessment of PSMA expression. The tracers [18F]FDG and [18F]choline are suitable for in vitro assessment of response to docetaxel therapy, whereas [68Ga]PSMA is not. PSMA expression seems to be a critical, but not unique, factor for the sensitivity of LNCaP cells to docetaxel. However, the loss of PSMA, as induced in the knockdown model, as well as unknown factors seem to play an important role.
KW  - Positronen-Emissions-Tomografie
KW  - PSMA
KW  - [18]F-Cholin
KW  - [68]Ga-PSMA I&T
KW  - Docetaxel
KW  - LNCaP
KW  - [18]F-choline
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176299
ER  - 
TY  - JOUR
A1  - Schuhmann, Sarah
A1  - Eberlein, Uta
A1  - Müller, Jessica
A1  - Scherthan, Harry
A1  - Lassmann, Michael
T1  - Correlation of the absorbed dose to the blood and DNA damage in leukocytes after internal ex-vivo irradiation of blood samples with Ra-224
JF  - EJNMMI Research
N2  - Background:
Irradiation with α-particles creates densely packed damage tracks along particle trajectories in exposed cells, including complex DNA damage and closely spaced double-strand breaks (DSBs) in hit nuclei. Here, we investigated the correlation of the absorbed dose to the blood and the number of α-induced DNA damage tracks elicited in human blood leukocytes after ex-vivo in-solution exposure with Ra-224. The aim was to compare the data to previously published data on Ra-223 and to investigate differences in DNA damage induction between the two radium isotopes.

Results:
Blood samples from three healthy volunteers were exposed ex-vivo to six different concentrations of Ra-224 dichloride. Absorbed doses to the blood were calculated assuming local energy deposition of all α- and β-particles of the Ra-224 decay chain, ranging from 0 to 127 mGy. γ-H2AX + 53BP1 DNA damage co-staining and analysis was performed on ethanol-fixed leukocytes isolated from the irradiated blood samples. For damage quantification, α-induced DNA damage tracks and small γ-H2AX + 53BP1 DSB foci were enumerated in the exposed leukocytes. This revealed a linear relationship between the frequency of α-induced γ-H2AX damage tracks and the absorbed dose to the blood, while the frequency of small γ-H2AX + 53BP1 DSB foci indicative of β-irradiation was similar to baseline values.

Conclusions:
Our data provide a first estimation of the DNA damage induced by Ra-224 in peripheral blood mononuclear cells. A comparison with our previously published Ra-223 data suggests that there is no difference in the induction of radiation-induced DNA damage between the two radium isotopes due to their similar decay properties.
KW  - 53BP1
KW  - DNA damage
KW  - γ-H2AX
KW  - biological dosimetry
KW  - absorbed dose to the blood
KW  - α-emitter
KW  - Ra-224
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176593
VL  - 8
IS  - 77
ER  - 
TY  - JOUR
A1  - Schumann, Sarah
A1  - Eberlein, Uta
A1  - Muhtadi, Razan
A1  - Lassmann, Michael
A1  - Scherthan, Harry
T1  - DNA damage in leukocytes after internal ex-vivo irradiation of blood with the α-emitter Ra-223
JF  - Scientific Reports
N2  - Irradiation with high linear energy transfer α-emitters, like the clinically used Ra-223 dichloride, severely damages cells and induces complex DNA damage including closely spaced double-strand breaks (DSBs). As the hematopoietic system is an organ-at-risk for the treatment, knowledge about Ra-223-induced DNA damage in blood leukocytes is highly desirable. Therefore, 36 blood samples from six healthy volunteers were exposed ex-vivo (in solution) to different concentrations of Ra-223. Absorbed doses to the blood were calculated assuming local energy deposition of all α- and β-particles of the decay, ranging from 0 to 142 mGy. γ-H2AX + 53BP1 co-staining and analysis was performed in leukocytes isolated from the irradiated blood samples. For DNA damage quantification, leukocyte samples were screened for occurrence of α-induced DNA damage tracks and small γ-H2AX + 53BP1 DSB foci. This revealed a linear relationship between the frequency of α-induced γ-H2AX damage tracks and the absorbed dose to the blood, while the frequency of small γ-H2AX + 53BP1 DSB foci indicative of β-irradiation was similar to baseline values, being in agreement with a negligible β-contribution (3.7%) to the total absorbed dose to the blood. Our calibration curve will contribute to the biodosimetry of Ra-223-treated patients and early after incorporation of α-emitters.
KW  - alpha particles
KW  - blood
KW  - DNA Breaks
KW  - double-stranded
KW  - gamma rays
KW  - healthy volunteers
KW  - humans
KW  - leukocytes
KW  - radiation effects
KW  - radium
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175596
VL  - 8
IS  - 2286
ER  - 
TY  - JOUR
A1  - Soares Machado, J.
A1  - Tran-Gia, J.
A1  - Schlögl, S.
A1  - Buck, A. K.
A1  - Lassmann, M.
T1  - Biokinetics, dosimetry, and radiation risk in infants after \(^{99m}\)Tc-MAG3 scans
JF  - EJNMMI Research
N2  - Background:
Renal scans are among the most frequent exams performed on infants and toddlers. Due to the young age, this patient group can be classified as a high-risk group with a higher probability for developing stochastic radiation effects compared to adults. As there are only limited data on biokinetics and dosimetry in this patient group, the aim of this study was to reassess the dosimetry and the associated radiation risk for infants undergoing \(^{99m}\)Tc-MAG3 renal scans based on a retrospective analysis of existing patient data. Consecutive data were collected from 20 patients younger than 20 months (14 males; 6 females) with normal renal function undergoing \(^{99m}\)Tc-MAG3 scans. To estimate the patient-specific organ activity, a retrospective calibration was performed based on a set of two 3D-printed infant kidneys filled with known activities. Both phantoms were scanned at different positions along the anteroposterior axis inside a water phantom, providing depth- and size-dependent attenuation correction factors for planar imaging. Time-activity curves were determined by drawing kidney, bladder, and whole-body regions-of-interest for each patient, and subsequently applying the calibration factor for conversion of counts to activity. Patient-specific time-integrated activity coefficients were obtained by integrating the organ-specific time-activity curves. Absorbed and effective dose coefficients for each patient were assessed with OLINDA/EXM for the provided newborn and 1-year-old model. The risk estimation was performed individually for each of the 20 patients with the NCI Radiation Risk Assessment Tool.

Results:
The mean age of the patients was 7.0 ± 4.5 months, with a weight between 5 and 12 kg and a body size between 60 and 89 cm. The injected activities ranged from 12 to 24 MBq of \(^{99m}\)Tc-MAG3. The patients' organ-specific mean absorbed dose coefficients were 0.04 ± 0.03 mGy/MBq for the kidneys and 0.27 ± 0.24 mGy/MBq for the bladder. The mean effective dose coefficient was 0.02 ± 0.02 mSv/MBq. Based on the dosimetry results, an evaluation of the excess lifetime risk for the development of radiation-induced cancer showed that the group of newborns has a risk of 16.8 per 100,000 persons, which is about 12% higher in comparison with the 1-year-old group with 14.7 per 100,000 persons (all values are given as mean plus/minus one standard deviation except otherwise specified).

Conclusion:
In this study, we retrospectively derived new data on biokinetics and dosimetry for infants with normal kidney function after undergoing renal scans with \(^{99m}\)Tc-MAG3. In addition, we analyzed the associated age- and gender-specific excess lifetime risk due to ionizing radiation. The radiation-associated stochastic risk increases with the organ doses, taking age- and gender-specific influences into account. Overall, the lifetime radiation risk associated with the \(^{99m}\)Tc-MAG3 scans is very low in comparison to the general population risk for developing cancer.
KW  - \(^{99m}\)Tc-MAG3
KW  - absorbed dose
KW  - biokinetics
KW  - dosimetry
KW  - pediatric patients
KW  - risk assessment
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175582
VL  - 8
IS  - 10
ER  - 
TY  - JOUR
A1  - Kazuhino, Koshino
A1  - Werner, Rudolf A.
A1  - Toriumi, Fuijo
A1  - Javadi, Mehrbod S.
A1  - Pomper, Martin G.
A1  - Solnes, Lilja B.
A1  - Verde, Franco
A1  - Higuchi, Takahiro
A1  - Rowe, Steven P.
T1  - Generative Adversarial Networks for the Creation of Realistic Artificial Brain Magnetic Resonance Images
JF  - Tomography
N2  - Even as medical data sets become more publicly accessible, most are restricted to specific medical conditions. Thus, data collection for machine learning approaches remains challenging, and synthetic data augmentation, such as generative adversarial networks (GAN), may overcome this hurdle. In the present quality control study, deep convolutional GAN (DCGAN)-based human brain magnetic resonance (MR) images were validated by blinded radiologists. In total, 96 T1-weighted brain images from 30 healthy individuals and 33 patients with cerebrovascular accident were included. A training data set was generated from the T1-weighted images and DCGAN was applied to generate additional artificial brain images. The likelihood that images were DCGAN-created versus acquired was evaluated by 5 radiologists (2 neuroradiologists [NRs], vs 3 non-neuroradiologists [NNRs]) in a binary fashion to identify real vs created images. Images were selected randomly from the data set (variation of created images, 40%-60%). None of the investigated images was rated as unknown. Of the created images, the NRs rated 45% and 71% as real magnetic resonance imaging images (NNRs, 24%, 40%, and 44%). In contradistinction, 44% and 70% of the real images were rated as generated images by NRs (NNRs, 10%, 17%, and 27%). The accuracy for the NRs was 0.55 and 0.30 (NNRs, 0.83, 0.72, and 0.64). DCGAN-created brain MR images are similar enough to acquired MR images so as to be indistinguishable in some cases. Such an artificial intelligence algorithm may contribute to synthetic data augmentation for "data-hungry" technologies, such as supervised machine learning approaches, in various clinical applications.
KW  - AI
KW  - Magnetresonanztomografie
KW  - artificial intelligence
KW  - magnetic resonance imaging
KW  - MRI
KW  - DCGAN
KW  - GAN
KW  - stroke
KW  - machine learning
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172185
VL  - 4
IS  - 4
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Weich, Alexander
A1  - Kircher, Malte
A1  - Solnes, Lilja B.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Rowe, Steven
A1  - Lapa, Constantin
T1  - The theranostic promise for neuroendocrine tumors in the late 2010s – Where do we stand, where do we go?
JF  - Theranostics
N2  - More than 25 years after the first peptide receptor radionuclide therapy (PRRT), the concept of somatostatin receptor (SSTR)-directed imaging and therapy for neuroendocrine tumors (NET) is seeing rapidly increasing use. To maximize the full potential of its theranostic promise, efforts in recent years have expanded recommendations in current guidelines and included the evaluation of novel theranostic radiotracers for imaging and treatment of NET. Moreover, the introduction of standardized reporting framework systems may harmonize PET reading, address pitfalls in interpreting SSTR-PET/CT scans and guide the treating physician in selecting PRRT candidates. Notably, the concept of PRRT has also been applied beyond oncology, e.g. for treatment of inflammatory conditions like sarcoidosis. Future perspectives may include the efficacy evaluation of PRRT compared to other common treatment options for NET, novel strategies for closer monitoring of potential side effects, the introduction of novel radiotracers with beneficial pharmacodynamic and kinetic properties or the use of supervised machine learning approaches for outcome prediction. This article reviews how the SSTR-directed theranostic concept is currently applied and also reflects on recent developments that hold promise for the future of theranostics in this context.
KW  - theranostics
KW  - Positronen-Emissions-Tomografie
KW  - PRRT
KW  - somatostatin receptor
KW  - peptide receptor radionuclide therapy
KW  - neuroendocrine tumor
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170264
VL  - 8
IS  - 22
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Eissler, Christoph
A1  - Hayakawa, Nobuyuki
A1  - Arias-Loza, Paula
A1  - Wakabayashi, Hiroshi
A1  - Javadi, Mehrbod S.
A1  - Chen, Xinyu
A1  - Shinaji, Tetsuya
A1  - Lapa, Constantin
A1  - Pelzer, Theo
A1  - Higuchi, Takahiro
T1  - Left Ventricular Diastolic Dysfunction in a Rat Model of Diabetic Cardiomyopathy using ECG-gated \(^{18}\)F-FDG PET
JF  - Scientific Reports
N2  - In diabetic cardiomyopathy, left ventricular (LV) diastolic dysfunction is one of the earliest signs of cardiac involvement prior to the definitive development of heart failure (HF). We aimed to explore the LV diastolic function using electrocardiography (ECG)-gated \(^{18}\)F-fluorodeoxyglucose positron emission tomography (\(^{18}\)F-FDG PET) imaging beyond the assessment of cardiac glucose utilization in a diabetic rat model. ECG-gated \(^{18}\)F-FDG PET imaging was performed in a rat model of type 2 diabetes (ZDF fa/fa) and ZL control rats at age of 13 weeks (n=6, respectively). Under hyperinsulinemic-euglycemic clamp to enhance cardiac activity, \(^{18}\)F-FDG was administered and subsequently, list-mode imaging using a dedicated small animal PET system with ECG signal recording was performed. List-mode data were sorted and reconstructed into tomographic images of 16 frames per cardiac cycle. Left ventricular functional parameters (systolic: LV ejection fraction (EF), heart rate (HR) vs. diastolic: peak filling rate (PFR)) were obtained using an automatic ventricular edge detection software. No significant difference in systolic function could be obtained (ZL controls vs. ZDF rats: LVEF, 62.5±4.2 vs. 59.4±4.5%; HR: 331±35 vs. 309±24 bpm; n.s., respectively). On the contrary, ECG-gated PET imaging showed a mild but significant decrease of PFR in the diabetic rats (ZL controls vs. ZDF rats: 12.1±0.8 vs. 10.2±1 Enddiastolic Volume/sec, P<0.01). Investigating a diabetic rat model, ECG-gated \(^{18}\)F-FDG PET imaging detected LV diastolic dysfunction while systolic function was still preserved. This might open avenues for an early detection of HF onset in high-risk type 2 diabetes before cardiac symptoms become apparent.
KW  - diabetic cardiomyopathy
KW  - personalized treatment
KW  - precision medicine
KW  - ZDF rats
KW  - ECG
KW  - PET
KW  - \(^{18}\)F-fluorodeoxyglucose
KW  - \(^{18}\)F-FDG
KW  - diabetes
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171765
VL  - 8
IS  - 17631
ER  - 
TY  - JOUR
A1  - Chen, Xinyu
A1  - Werner, Rudolf A.
A1  - Javadi, Mehrbod S.
A1  - Maya, Yoshifumi
A1  - Decker, Michael
A1  - Lapa, Constantin
A1  - Herrmann, Ken
A1  - Higuchi, Takahiro
T1  - Radionuclide imaging of neurohormonal system of the heart
JF  - Theranostics
N2  - Heart failure is one of the growing causes of death especially in developed countries due to longer life expectancy. Although many pharmacological and instrumental therapeutic approaches have been introduced for prevention and treatment of heart failure, there are still limitations and challenges. Nuclear cardiology has experienced rapid growth in the last few decades, in particular the application of single photon emission computed tomography (SPECT) and positron emission tomography (PET), which allow non-invasive functional assessment of cardiac condition including neurohormonal systems involved in heart failure; its application has dramatically improved the capacity for fundamental research and clinical diagnosis. In this article, we review the current status of applying radionuclide technology in non-invasive imaging of neurohormonal system in the heart, especially focusing on the tracers that are currently available. A short discussion about disadvantages and perspectives is also included.
KW  - SPECT
KW  - radiotracer
KW  - heart failure
KW  - cardiac neurohormonal system
KW  - nuclear cardiology
KW  - PET
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149205
VL  - 5
IS  - 6
ER  - 
TY  - JOUR
A1  - Philipp-Abbrederis, Kathrin
A1  - Herrmann, Ken
A1  - Knop, Stefan
A1  - Schottelius, Margret
A1  - Eiber, Matthias
A1  - Lückerath, Katharina
A1  - Pietschmann, Elke
A1  - Habringer, Stefan
A1  - Gerngroß, Carlos
A1  - Franke, Katharina
A1  - Rudelius, Martina
A1  - Schirbel, Andreas
A1  - Lapa, Constantin
A1  - Schwamborn, Kristina
A1  - Steidle, Sabine
A1  - Hartmann, Elena
A1  - Rosenwald, Andreas
A1  - Kropf, Saskia
A1  - Beer, Ambros J
A1  - Peschel, Christian
A1  - Einsele, Hermann
A1  - Buck, Andreas K
A1  - Schwaiger, Markus
A1  - Götze, Katharina
A1  - Wester, Hans-Jürgen
A1  - Keller, Ulrich
T1  - In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma
JF  - EMBO Molecular Medicine
N2  - CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination andpoor prognosis. We evaluated the novel CXCR4 probe [\(^{68}\)Ga]Pentixafor for invivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [\(^{68}\)Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [\(^{68}\)Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [\(^{18}\)F]fluorodeoxyglucose PET/CT scans were rated visually positive. Assessment of blood counts and standard CD34\(^{+}\) flow cytometry did not reveal significant blood count changes associated with tracer application. Based on these highly encouraging data on clinical PET imaging of CXCR4 expression in a cohort of MM patients, we conclude that [\(^{68}\)Ga]Pentixafor PET opens a broad field for clinical investigations on CXCR4 expression and for CXCR4-directed therapeutic approaches in MM and other diseases.
KW  - FDG PET/CT
KW  - cells
KW  - CXCR4/SDF-1
KW  - CXCR4
KW  - multiple myeloma
KW  - positron emission tomography
KW  - chemokine receptor
KW  - in vivo imaging
KW  - malignancies
KW  - involvement
KW  - microenvironment
KW  - survival
KW  - cancer
KW  - autologous transplantation
KW  - bone disease
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148738
VL  - 7
IS  - 4
ER  - 
TY  - JOUR
A1  - Eberlein, Uta
A1  - Peper, Michel
A1  - Fernández, Maria
A1  - Lassmann, Michael
A1  - Scherthan, Harry
T1  - Calibration of the \(\gamma\)-H2AX DNA double strand break focus assay for internal radiation exposure of blood lymphocytes
JF  - PLoS ONE
N2  - DNA double strand break (DSB) formation induced by ionizing radiation exposure is indicated by the DSB biomarkers \(\gamma\)-H2AX and 53BP1. Knowledge about DSB foci formation in-vitro after internal irradiation of whole blood samples with radionuclides in solution will help us to gain detailed insights about dose-response relationships in patients after molecular radiotherapy (MRT). Therefore, we studied the induction of radiation-induced co-localizing \(\gamma\)-H2AX and 53BP1 foci as surrogate markers for DSBs in-vitro, and correlated the obtained foci per cell values with the in-vitro absorbed doses to the blood for the two most frequently used radionuclides in MRT (I-131 and Lu-177). This approach led to an in-vitro calibration curve. Overall, 55 blood samples of three healthy volunteers were analyzed. For each experiment several vials containing a mixture of whole blood and radioactive solutions with different concentrations of isotonic NaCl-diluted radionuclides with known activities were prepared. Leukocytes were recovered by density centrifugation after incubation and constant blending for 1 h at 37°C. After ethanol fixation they were subjected to two-color immunofluorescence staining and the average frequencies of the co-localizing \(\gamma\)-H2AX and 53BP1 foci/nucleus were determined using a fluorescence microscope equipped with a red/green double band pass filter. The exact activity was determined in parallel in each blood sample by calibrated germanium detector measurements. The absorbed dose rates to the blood per nuclear disintegrations occurring in 1 ml of blood were calculated for both isotopes by a Monte Carlo simulation. The measured blood doses in our samples ranged from 6 to 95 mGy. A linear relationship was found between the number of DSB-marking foci/nucleus and the absorbed dose to the blood for both radionuclides studied. There were only minor nuclide-specific intra-and inter-subject deviations.
KW  - in vivo formation
KW  - chromatin mobility
KW  - phosphorylation
KW  - repair
KW  - 53BP1
KW  - damage
KW  - radioiodine therapy
KW  - thyroid cancer
KW  - histone H2AX
KW  - dose response
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148697
VL  - 10
IS  - 4
ER  - 
TY  - JOUR
A1  - Lückerath, Katharina
A1  - Lapa, Constantin
A1  - Albert, Christa
A1  - Herrmann, Ken
A1  - Jörg, Gerhard
A1  - Samnick, Samuel
A1  - Einsele, Herrmann
A1  - Knop, Stefan
A1  - Buck, Andreas K.
T1  - \(^{11}\)C-Methionine-PET: a novel and sensitive tool for monitoring of early response to treatment in multiple myeloma
JF  - Oncotarget
N2  - Multiple myeloma (MM) remains an essentially incurable hematologic malignancy. However, new treatment modalities and novel drugs have been introduced and thus additional tools for therapy monitoring are increasingly needed. Therefore, we evaluated the radiotracers \(^{11}\)C-Methionine (paraprotein-biosynthesis) and \(^{18}\)F-FDG (glucose-utilization) for monitoring response to anti-myeloma-therapy and outcome prediction. Influence of proteasome-inhibition on radiotracer-uptake of different MM cell-lines and patient-derived CD138\(^{+}\) plasma cells was analyzed and related to tumor-biology. Mice xenotransplanted with MM. 1S tumors underwent MET- and FDG-\(\mu\)PET. Tumor-to-background ratios before and after 24 h, 8 and 15 days treatment with bortezomib were correlated to survival. Treatment reduced both MET and FDG uptake; changes in tracer-retention correlated with a switch from high to low CD138-expression. In xenotransplanted mice, MET-uptake significantly decreased by 30-79% as early as 24 h after bortezomib injection. No significant differences were detected thus early with FDG. This finding was confirmed in patient-derived MM cells. Importantly, early reduction of MET-but not FDG-uptake correlated with improved survival and reduced tumor burden in mice. Our results suggest that MET is superior to FDG in very early assessment of response to anti-myeloma-therapy. Early changes in MET-uptake have predictive potential regarding response and survival. MET-PET holds promise to individualize therapies in MM in future.
KW  - positron emission tomography
KW  - imaging techniques
KW  - experience
KW  - \(^{11}\)C-Methionine-PET
KW  - treatment response
KW  - molecular imaging
KW  - multiple myeloma
KW  - management
KW  - \(^{18}\)F-FDG PET/CT
KW  - bone disease
KW  - stem-cell transplantation
KW  - esophagogastric junction
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148688
VL  - 6
IS  - 10
ER  - 
TY  - JOUR
A1  - Nose, Naoko
A1  - Werner, Rudolf A.
A1  - Ueda, Yuichiro
A1  - Günther, Katharina
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
A1  - Fukushima, Kazuhito
A1  - Edenhofer, Frank
A1  - Higuchi, Takahiro
T1  - Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay
JF  - International Journal of Cardiology
N2  - BACKGROUND:
Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay.

MATERIAL AND METHODS:
Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F‑2‑fluoro‑2‑deoxy‑d‑glucose (\(^{18}\)F-FDG) and \(^{125}\)I‑β‑methyl‑iodophenyl‑pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively.

RESULTS:
After cardiac differentiation of hiPSCs, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM.

CONCLUSIONS:
During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications.
KW  - tracer
KW  - Stammzelle
KW  - induced pluripotent stem cells
KW  - cardiomyocytes
KW  - fatty acid
KW  - stem cell therapy
KW  - hiPSC-CM
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170699
VL  - 269
ER  - 
TY  - JOUR
A1  - Werner, Rudolf
A1  - Hänscheid, Heribert
A1  - Leal, Jeffrey P.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Lodge, Martin A.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - Impact of Tumor Burden on Quantitative [\(^{68}\)Ga]DOTATOC Biodistribution
JF  - Molecular Imaging and Biology
N2  - Purpose: As has been previously reported, the somatostatin receptor (SSTR) imaging agent [\(^{68}\)Ga]-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotate ([\(^{68}\)Ga]DOTATATE) demonstrates lower uptake in normal organs in patients with a high neuroendocrine tumor (NET) burden. Given the higher SSTR affinity of [\(^{68}\)Ga]DOTATATE, we aimed to quantitatively investigate the biodistribution of [\(^{68}\)Ga]-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotide ([68Ga]DOTATOC) to determine a potential correlation between uptake in normal organs and NET burden.
Procedures: Of the 44 included patients, 36/44 (82%) patients demonstrated suspicious radiotracer uptake on [\(^{68}\)Ga]DOTATOC positron emission tomography (PET)/x-ray computed tomography (CT). Volumes of Interest (VOIs) were defined for tumor lesions and normal organs (spleen, liver, kidneys, adrenals). Mean body weight corrected standardized uptake value (SUV\(_{mean}\)) for normal organs was assessed and was used to calculate the corresponding mean specific activity uptake (Upt: fraction of injected activity per kg of tissue). For the entire tumor burden, SUV\(_{mean}\), maximum standardized uptake value (SUV\(_{max}\)), and the total mass (TBM) was calculated and the decay corrected tumor fractional uptake (TBU) was assessed. A Spearman’s rank correlation coefficient was used to determine the correlations between normal organ uptake and tumor burden. 
Results: The median SUV\(_{mean}\) was 18.7 for the spleen (kidneys, 9.2; adrenals, 6.8; liver, 5.6). For tumor burden, the median values were SUV\(_{mean}\) 6.9, SUV\(_{max}\) 35.5, TBM 42.6g, and TBU 1.2%. With increasing volume of distribution, represented by lean body mass and body surface area (BSA), Upt decreased in kidneys, liver, and adrenal glands and SUV\(_{mean}\) increased in the spleen. Correlation improved only for both kidneys and adrenals when the influence of the tumor uptake on the activity available for organ uptake was taken into account by the factor 1/(1-TBU). TBU was neither predictive for SUV\(_{mean}\) nor for Upt in any of the organs. The distribution of organ Upt vs. BSA/(1-TBU) were not different for patients with minor TBU (<3%) vs. higher TBU (>7%), indicating that the correlations observed in the present study are explainable by the body size effect. High tumor mass and uptake mitigated against G1 NET. 
Conclusions: There is no significant impact on normal organ biodistribution with increasing tumor burden on [\(^{68}\)Ga]DOTATOC PET/CT. Potential implications include increased normal organ dose with [\(^{177}\)Lu-DOTA]\(^0\)-D-Phe\(^1\)-Tyr\(^3\)-Octreotide and decreased absolute lesion detection with [\(^{68}\)Ga]DOTATOC in high NET burden.
KW  - somatostatin receptor
KW  - Positronen-Emissions-Tomografie
KW  - quantification
KW  - [68Ga]DOTATOC
KW  - neuroendocrine tumor
KW  - SSTR-PET
KW  - theranostics
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170280
ER  - 
TY  - JOUR
A1  - Werner, R.A.
A1  - Schmid, J.S.
A1  - Muegge, D.O.
A1  - Lückerath, K.
A1  - Higuchi, T.
A1  - Hänscheid, H.
A1  - Grelle, I.
A1  - Reiners, C.
A1  - Herrmann, K.
A1  - Buck, A.K.
A1  - Lapa, C.
T1  - Prognostic value of serum tumor markers in medullary thyroid cancer patients undergoing vandetanib treatment
JF  - Medicine
N2  - Tyrosine kinase inhibitors (TKIs) such as vandetanib have shown clinical effectiveness in advanced medullary thyroid cancer (MTC). During TKI treatment, fluctuations in the tumor markers carcinoembryonic antigen (CEA) and calcitonin (CTN) are frequently observed. Their role for treatment monitoring and the decision-making process has not been fully elucidated yet.
Twenty-one patients (male, 16, female, 5; mean age, 49±13 years) with progressive MTC receiving vandetanib (300mg orally per day) were considered. Tumor restaging was performed every 3 months including contrast-enhanced computed tomography (CT). Response was assessed according to recent criteria (Response Evaluation Criteria in Solid Tumors, RECIST 1.1). Additionally, CEA and CTN were measured at the day of CT imaging and alterations observed in tumor markers were compared to respective imaging findings (partial response, PR; stable disease, SD; progressive disease, PD).
During long-term follow-up (510±350 days [range, 97-1140 days]), CTN and CEA levels initially dropped in 71.4% and 61.9% of the patients followed by fluctuations in serum marker levels. A rise in CTN ≥39.5% between 2 subsequent measurements (defined by ROC analysis) had a sensitivity of 70.6% and a specificity of 83.2% in predicting PD with an accuracy of 82.0% (area under the curve (AUC), 0.76). Oscillations in CEA levels were not predictive for PD.
Whereas tumor marker fluctuations in MTC patients undergoing TKI treatment are a frequent phenomenon, a significant rise in CTN ≥40% turns out to as an early indicator of tumor progression.
KW  - follow-up
KW  - kinase inhibitor
KW  - carcinoma
KW  - calcitonin
KW  - trial
KW  - medullary thyroid cancer
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-145154
VL  - 94
IS  - 45
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Chen, Xinyu
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
T1  - Moving into the Next Era of PET Myocardial Perfusion Imaging - Introduction of Novel \(^{18}\)F-labeled Tracers
JF  - The International Journal of Cardiovascular Imaging
N2  - The heart failure (HF) epidemic continues to rise with coronary artery disease (CAD) as one of its main causes. Novel concepts for risk stratification to guide the referring cardiologist towards revascularization procedures are of significant value. Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) agents has demonstrated high accuracy for the detection of clinically relevant stenoses. With positron emission tomography (PET) becoming more widely available, mainly due to its diagnostic performance in oncology, perfusion imaging with that modality is more practical than in the past and overcomes existing limitations of SPECT MPI. Advantages of PET include more reliable quantification of absolute myocardial blood flow, the routine use of computed tomography for attenuation correction, a higher spatiotemporal resolution and a higher count sensitivity. Current PET radiotracers such as rubidium-82 (half-life, 76 sec), oxygen-15 water (2 min) or nitrogen-13 ammonia (10 min) are labeled with radionuclides with very short half-lives, necessitating that stress imaging is performed under pharmacological vasodilator stress instead of exercise testing. However, with the introduction of novel 18F-labeled MPI PET radiotracers (half-life, 110 min), the intrinsic advantages of PET can be combined with exercise testing. Additional advantages of those radiotracers include, but are not limited to: potentially improved cost-effectiveness due to the use of pre-existing delivery systems and superior imaging qualities, mainly due to the shortest positron range among available PET MPI probes. In the present review, widely used PET MPI radiotracers will be reviewed and potential novel 18F-labeled perfusion radiotracers will be discussed.
KW  - heart failure with mid-range ejection fraction
KW  - Positronenemissionstomografie
KW  - coronary artery disease
KW  - precision medicine
KW  - positron emission tomography
KW  - PET
KW  - SPECT
KW  - myocardial perfusion imaging
KW  - MPI
KW  - 18F-flurpiridaz
KW  - 18FFBnTP
KW  - HFmrEF
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169134
SN  - 1569-5794
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
T1  - Editorial: Cardiac Innervation Imaging as a Risk Stratification Tool for Potential Device Therapy Candidates
JF  - Journal of Nuclear Cardiology
N2  - As a scintigraphic approach evaluating cardiac nerve integrity, \(^{123}\)I-metaiodobenzylguanidine (123I-mIBG) has been recently Food and Drug Administration approved. A great deal of progress has been made by the prospective ADMIRE-HF trial, which primarily demonstrated the association of denervated myocardium assessed by \(^{123}\)I-mIBG and cardiac events. However, apart from risk stratification, myocardial nerve function evaluated by molecular imaging should also be expanded to other clinical contexts, in particular to guide the referring cardiologist in selecting appropriate candidates for specific therapeutic interventions. In the present issue of the Journal of Nuclear Cardiology, the use of 123I-mIBG for identifying cardiomyopathy patients, which would most likely not benefit from ICD due low risk of arrhythmias, is described. If we aim to deliver on the promise of cardiac innervation imaging as a powerful tool for risk stratification in a manner similar to nuclear oncology, studies such as the one reviewed here may imply an important step to lay the proper groundwork for a more widespread adoption in clinical practice.
KW  - SPECT
KW  - SPECT
KW  - myocardial nerve
KW  - 123I-metaiodobenzylguanidine
KW  - 123I-mIBG
KW  - cardiac nerve
KW  - ICD
KW  - arrhythmia
KW  - cardiac innervation imaging
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168465
UR  - https://rdcu.be/970i
SN  - 1071-3581
N1  - SharedIt-Link zur Publikation: 
https://rdcu.be/970i
N1  - This is a post-peer-review, pre-copyedit version of an article published in Journal of Nuclear Cardiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s12350-018-01475-0
ER  - 
TY  - JOUR
A1  - Canessa, Andrea
A1  - Pozzi, Nicolò G.
A1  - Arnulfo, Gabriele
A1  - Brumberg, Joachim
A1  - Reich, Martin M.
A1  - Pezzoli, Gianni
A1  - Ghilardi, Maria F.
A1  - Matthies, Cordula
A1  - Steigerwald, Frank
A1  - Volkmann, Jens
A1  - Isaias, Ioannis U.
T1  - Striatal Dopaminergic Innervation Regulates Subthalamic Beta-Oscillations and Cortical-Subcortical Coupling during Movements: Preliminary Evidence in Subjects with Parkinson's Disease
JF  - Frontiers in Human Neuroscience
N2  - Activation of the basal ganglia has been shown during the preparation and execution of movement. However, the functional interaction of cortical and subcortical brain areas during movement and the relative contribution of dopaminergic striatal innervation remains unclear. We recorded local field potential (LFP) activity from the subthalamic nucleus (STN) and high-density electroencephalography (EEG) signals in four patients with Parkinson’s disease (PD) off dopaminergic medication during a multi-joint motor task performed with their dominant and non-dominant hand. Recordings were performed by means of a fully-implantable deep brain stimulation (DBS) device at 4 months after surgery. Three patients also performed a single-photon computed tomography (SPECT) with [123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane (FP-CIT) to assess striatal dopaminergic innervation. Unilateral movement execution led to event-related desynchronization (ERD) followed by a rebound after movement termination event-related synchronization (ERS) of oscillatory beta activity in the STN and primary sensorimotor cortex of both hemispheres. Dopamine deficiency directly influenced movement-related beta-modulation, with greater beta-suppression in the most dopamine-depleted hemisphere for both ipsi- and contralateral hand movements. Cortical-subcortical, but not interhemispheric subcortical coherencies were modulated by movement and influenced by striatal dopaminergic innervation, being stronger in the most dopamine-depleted hemisphere. The data are consistent with a role of dopamine in shielding subcortical structures from an excessive cortical entrapment and cross-hemispheric coupling, thus allowing fine-tuning of movement.
KW  - beta oscillations
KW  - Parkinson’s disease
KW  - motor control
KW  - movement disorders
KW  - imaging
KW  - subthalamic nucleus
KW  - coherence analysis
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164061
VL  - 10
IS  - 611
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Higuchi, Takahiro
A1  - Javadi, Mehrbod S.
A1  - Rowe, Steven P.
A1  - Zsótér, Norbert
A1  - Kroiss, Matthias
A1  - Fassnacht, Martin
A1  - Buck, Andreas K.
A1  - Kreissl, Michael C.
A1  - Lapa, Constantin
T1  - Volumetric and Texture Analysis of Pretherapeutic \(^{18}\)F-FDG PET can Predict Overall Survival in Medullary Thyroid Cancer Patients Treated with Vandetanib
JF  - Endocrine
N2  - Purpose: The metabolically most active lesion in 2-deoxy-2-(\(^{18}\)F)fluoro-D-glucose (\(^{18}\)F-FDG) PET/CT can predict progression-free survival (PFS) in patients with medullary thyroid carcinoma (MTC) starting treatment with the tyrosine kinase inhibitor (TKI) vandetanib. However, this metric failed in overall survival (OS) prediction. In the present proof of concept study, we aimed to explore the prognostic value of intratumoral textural features (TF) as well as volumetric parameters (total lesion glycolysis, TLG) derived by pre-therapeutic \(^{18}\)F-FDG PET. 
Methods: Eighteen patients with progressive MTC underwent baseline \(^{18}\)F-FDG PET/CT prior to and 3 months after vandetanib initiation. By manual segmentation of the tumor burden at baseline and follow-up PET, intratumoral TF and TLG were computed. The ability of TLG, imaging-based TF, and clinical parameters (including age, tumor marker doubling times, prior therapies and RET (rearranged during transfection) mutational status) for prediction of both PFS and OS were evaluated. 
Results: The TF Complexity and the volumetric parameter TLG obtained at baseline prior to TKI initiation successfully differentiated between low- and high-risk patients. Complexity allocated 10/18 patients to the high-risk group with an OS of 3.3y (vs. low-risk group, OS=5.3y, 8/18, AUC=0.78, P=0.03). Baseline TLG designated 11/18 patients to the high-risk group (OS=3.5y vs. low-risk group, OS=5y, 7/18, AUC=0.83, P=0.005). The Hazard Ratio for cancer-related death was 6.1 for Complexity (TLG, 9.5). Among investigated clinical parameters, the age at initiation of TKI treatment reached significance for PFS prediction (P=0.02, OS, n.s.). 
Conclusions: The TF Complexity and the volumetric parameter TLG are both independent parameters for OS prediction.
KW  - personalized medicine
KW  - Positronen-Emissions-Tomografie
KW  - medullary thyroid carcinoma
KW  - tyrosine kinase inhibitor
KW  - TKI
KW  - vandetanib
KW  - 18F-FDG
KW  - positron emission tomography
KW  - 2-deoxy-2-(18F)fluoro-D-glucose
KW  - PET
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167910
SN  - 1355-008X
ER  - 
TY  - JOUR
A1  - Chen, Xinyu
A1  - Hirano, Mitsuru
A1  - Werner, Rudolf A.
A1  - Decker, Michael
A1  - Higuchi, Takahiro
T1  - Novel \(^{18}\)F-labeled PET Imaging Agent FV45 targeting the Renin-Angiotensin System
JF  - ACS Omega
N2  - Renin–angiotensin system (RAS) plays an important role in the regulation of blood pressure and hormonal balance. Using positron emission tomography (PET) technology, it is possible to monitor the physiological and pathological distribution of angiotensin II type 1 receptors (AT\(_1\)), which reflects the functionality of RAS. A new \(^{18}\)F-labeled PET tracer derived from the clinically used AT\(_1\) antagonist valsartan showing the least possible chemical alteration from the valsartan structure has been designed and synthesized with several strategies, which can be applied for the syntheses of further derivatives. Radioligand binding study showed that the cold reference FV45 (K\(_i\) 14.6 nM) has almost equivalent binding affinity as its lead valsartan (K\(_i\) 11.8 nM) and angiotensin II (K\(_i\) 1.7 nM). Successful radiolabeling of FV45 in a one-pot radiofluorination followed by the deprotection procedure with 21.8 ± 8.5% radiochemical yield and >99% radiochemical purity (n = 5) enabled a distribution study in rats and opened a path to straightforward large-scale production. A fast and clear kidney uptake could be observed, and this renal uptake could be selectively blocked by pretreatment with AT\(_1\)-selective antagonist valsartan. Overall, as the first \(^{18}\)F-labeled PET tracer based on a derivation from clinically used drug valsartan with almost identical chemical structure, [\(^{18}\)F]FV45 will be a new tool for assessing the RAS function by visualizing AT\(_i\) receptor distributions and providing further information regarding cardiovascular system malfunction as well as possible applications in inflammation research and cancer diagnosis.
KW  - FV45
KW  - Positronen-Emissions-Tomografie
KW  - renin-angiotensin system
KW  - angiotensin II type 1 receptor
KW  - valsartan
KW  - positron emission tomography
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167144
SN  - 2470-1343
N1  - This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html), which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
VL  - 3
IS  - 9
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Ilhan, Harun
A1  - Lehner, Sebastian
A1  - Papp, László
A1  - Zsótér, Norbert
A1  - Schatka, Imke
A1  - Muegge, Dirk O.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Bartenstein, Peter
A1  - Bengel, Frank
A1  - Essler, Markus
A1  - Lapa, Constantin
A1  - Bundschuh, Ralph A.
T1  - Pre-therapy Somatostatin-Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy
JF  - Molecular Imaging and Biology
N2  - Purpose: Early identification of aggressive disease could improve decision-support in pancreatic neuroendocrine tumor (pNET) patients prior to peptide receptor radionuclide therapy (PRRT). The prognostic value of intratumoral textural features (TF) determined by baseline somatostatin receptor (SSTR)-PET before PRRT was analyzed.
Procedures: 31 patients with G1/G2 pNET were enrolled (G2, n=23/31). Prior to PRRT with [\(^{177}\)Lu]DOTATATE (mean, 3.6 cycles), baseline SSTR-PET/CT was performed. By segmentation of 162 (median per patient, 5) metastases, intratumoral TF were computed. The impact of conventional PET parameters  (SUV\(_{mean/max}\)), imaging-based TF as well as clinical parameters (Ki67, CgA) for prediction of both progression-free (PFS) and overall survival (OS) after PRRT was evaluated.
Results: Within a median follow-up of 3.7y, tumor progression was detected in 21 patients (median, 1.5y) and 13/31 deceased (median, 1.9y). In ROC analysis, the TF Entropy, reflecting derangement on a voxel-by-voxel level, demonstrated predictive capability for OS (cutoff=6.7, AUC=0.71, p=0.02). Of note, increasing Entropy could predict a longer survival (>6.7, OS=2.5y, 17/31), whereas less voxel-based derangement portended inferior outcome (<6.7, OS=1.9y, 14/31). These findings were supported in a G2 subanalysis (>6.9, OS=2.8y, 9/23 vs. <6.9, OS=1.9y, 14/23). Kaplan-Meier analysis revealed a significant distinction between high- and low-risk groups using Entropy (n=31, p<0.05). For those patients below the ROC-derived threshold, the relative risk of death after PRRT was 2.73 (n=31, p=0.04). Ki67 was negatively associated with PFS (p=0.002); however, SUVmean/max failed in prognostication (n.s.).
Conclusions: In contrast to conventional PET parameters, assessment of intratumoral heterogeneity demonstrated superior prognostic performance in pNET patients undergoing PRRT. This novel PET-based strategy of outcome prediction prior to PRRT might be useful for patient risk stratification.
KW  - tumor heterogeneity
KW  - Positronen-Emissions-Tomografie
KW  - PET
KW  - PET/CT
KW  - pancreas
KW  - SSTR
KW  - [177Lu]-DOTATATE/-DOTATOC
KW  - [68Ga]
KW  - neuroendocrine tumor
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167168
SN  - 1536-1632
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Bundschuh, Lena
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Weich, Alexander
A1  - Sheikhbahaei, Sara
A1  - Pienta, Kenneth J.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - MI-RADS: Molecular Imaging Reporting and Data Systems – A Generalizable Framework for Targeted Radiotracers with Theranostic Implications
JF  - Annals of Nuclear Medicine
N2  - Both prostate-specific membrane antigen (PSMA)- and somatostatin receptor (SSTR)-targeted positron emission tomography (PET) imaging agents for staging and restaging of prostate carcinoma or neuroendocrine tumors, respectively, are seeing rapidly expanding use. In addition to diagnostic applications, both classes of radiotracers can be used to triage patients for theranostic endoradiotherapy. While interpreting PSMA- or SSTR-targeted PET/computed tomography (CT) scans, the reader has to be aware of certain pitfalls. Adding to the complexity of the interpretation of those imaging agents, both normal biodistribution, and also false-positive and -negative findings differ between PSMA- and SSTR-targeted PET radiotracers. Herein summarized under the umbrella term molecular imaging reporting and data systems (MI-RADS), two novel RADS classifications for PSMA- and SSTR-targeted PET imaging are described (PSMA- and SSTR-RADS). Both framework systems may contribute to increase the level of a reader’s confidence and to navigate the imaging interpreter through indeterminate lesions, so that appropriate workup for equivocal findings can be pursued. Notably, PSMA- and SSTR-RADS are structured in a reciprocal fashion, i.e. if the reader is familiar with one system, the other system can readily be applied as well. In the present review we will discuss the most common pitfalls on PSMA- and SSTR-targeted PET/CT, briefly introduce PSMA- and SSTR-RADS, and define a future role of the umbrella framework MI-RADS compared to other harmonization systems.
KW  - PET
KW  - Positronen-Emissions-Tomografie
KW  - prostate cancer
KW  - neuroendocrine tumor
KW  - prostate-specific membrane antigen (PSMA)
KW  - somatostatin receptor (SSTR)
KW  - positron emission tomography
KW  - theranostics
KW  - standardization
KW  - RADS
KW  - reporting and data systems
KW  - personalized medicine
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166995
SN  - 0914-7187
ER  - 
TY  - JOUR
A1  - Chen, Xinyu
A1  - Werner, Rudolf A.
A1  - Lapa, Constantin
A1  - Nose, Naoko
A1  - Hirano, Mitsuru
A1  - Javadi, Mehrbod S.
A1  - Robinson, Simon
A1  - Higuchi, Takahiro
T1  - Subcellular storage and release mode of the novel \(^{18}\)F-labeled sympathetic nerve PET tracer LMI1195
JF  - EJNMMI Research
N2  - Background: \(^{18}\)F-N-[3-bromo-4-(3-fluoro-propoxy)-benzyl]-guanidine (\(^{18}\)F-LMI1195) is a new class of PET tracer designed for sympathetic nervous imaging of the heart. The favorable image quality with high and specific neural uptake has been previously demonstrated in animals and humans, but intracellular behavior is not yet fully understood. The aim of the present study is to verify whether it is taken up in storage vesicles and released in company with vesicle turnover.
Results: Both vesicle-rich (PC12) and vesicle-poor (SK-N-SH) norepinephrine-expressing cell lines were used for in vitro tracer uptake studies. After 2 h of \(^{18}\)F-LMI1195 preloading into both cell lines, effects of stimulants for storage vesicle turnover (high concentration KCl (100 mM) or reserpine treatment) were measured at 10, 20, and 30 min. \(^{131}\)I-meta-iodobenzylguanidine (\(^{131}\)I-MIBG) served as a reference. Both high concentration KCl and reserpine enhanced \(^{18}\)F-LMI1195 washout from PC12 cells, while tracer retention remained stable in the SK-N-SH cells. After 30 min of treatment, 18F-LMI1195 releasing index (percentage of tracer released from cells) from vesicle-rich PC12 cells achieved significant differences compared to cells without treatment condition. In contrast, such effect could not be observed using vesicle-poor SK-N-SH cell lines. Similar tracer kinetics after KCl or reserpine treatment were also observed using 131I-MIBG. In case of KCl exposure, Ca\(^{2+}\)-free buffer with the calcium chelator, ethylenediaminetetracetic acid (EDTA), could suppress the tracer washout from PC12 cells. This finding is consistent with the tracer release being mediated by Ca\(^{2+}\) influx resulting from membrane depolarization.
Conclusions: Analogous to \(^{131}\)I-MIBG, the current in vitro tracer uptake study confirmed that \(^{131}\)F-LMI1195 is also stored in vesicles in PC12 cells and released along with vesicle turnover. Understanding the basic kinetics of \(^{18}\)FLMI1195 at a subcellular level is important for the design of clinical imaging protocols and imaging interpretation.
KW  - phaeochromocytoma
KW  - Positronen-Emissions-Tomografie
KW  - heart failure
KW  - sympathetic nervous system
KW  - storage vesicle turnover
KW  - positron emission tomography
KW  - 18F-LMI1195
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167081
SN  - 2191-219X
VL  - 8
IS  - 12
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Sheikhbahaei, Sara
A1  - Jones, Krystyna M.
A1  - Javadi, Mehrbod S.
A1  - Solnes, Lilja B.
A1  - Ross, Ashley E.
A1  - Allaf, Mohamad E.
A1  - Pienta, Kenneth J.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Gorin, Micheal A.
A1  - Rowe, Steven P.
T1  - Patterns of uptake of prostate-specific membrane antigen (PSMA)-targeted \(^{18}\)F-DCFPyL in peripheral ganglia
JF  - Annals of Nuclear Medicine
N2  - Objective: Radiotracers targeting prostate-specific membrane antigen (PSMA) have increasingly been recognized as showing uptake in a number of normal structures, anatomic variants, and non-prostate-cancer pathologies. We aimed to explore the frequency and degree of uptake in peripheral ganglia in patients undergoing PET with the PSMA-targeted agent \(^{18}\)F-DCFPyL. 
Methods: A total of 98 patients who underwent \(^{18}\)F-DCFPyL PET/CT imaging were retrospectively analyzed. This included 76 men with prostate cancer (PCa) and 22 patients with renal cell carcinoma (RCC; 13 men, 9 women). Scans were evaluated for uptake in the cervical, stellate, celiac, lumbar and sacral ganglia. Maximum standardized uptake value corrected to body weight (SUV\(_{max}\)), and maximum standardized uptake value corrected to lean body mass (SUL\(_{max}\)) were recorded for all ganglia with visible uptake above background. Ganglia-to-background ratios were calculated by dividing the SUV\(_{max}\) and SUL\(_{max}\) values by the mean uptake in the ascending aorta (Aortamean) and the right gluteus muscle (Gluteusmean). 
Results: Overall, 95 of 98 (96.9%) patients demonstrated uptake in at least one of the evaluated peripheral ganglia. With regard to the PCa cohort, the most frequent sites of radiotracer accumulation were lumbar ganglia (55/76, 72.4%), followed by the cervical ganglia (51/76, 67.1%). Bilateral uptake was found in the majority of cases [lumbar 44/55 (80%) and cervical 30/51 (58.8%)]. Additionally, discernible radiotracer uptake was recorded in 50/76 (65.8%) of the analyzed stellate ganglia and in 45/76 (59.2%) of the celiac ganglia, whereas only 5/76 (6.6%) of the sacral ganglia demonstrated \(^{18}\)F-DCFPyL accumulation. Similar findings were observed for patients with RCC, with the most frequent locations of radiotracer uptake in both the lumbar (20/22, 90.9%) and cervical ganglia (19/ 22, 86.4%). No laterality preference was found in mean PSMA-ligand uptake for either the PCa or RCC cohorts. 
Conclusion: As PSMA-targeted agents become more widely disseminated, the patterns of uptake in structures that are not directly relevant to patients’ cancers must be understood. This is the first systematic evaluation of the uptake of \(^{18}\)F-DCFPyL in ganglia demonstrating a general trend with a descending frequency of radiotracer accumulation in lumbar, cervical, stellate, celiac, and sacral ganglia. The underlying biology that leads to variability of PSMA-targeted radiotracers in peripheral ganglia is not currently understood, but may provide opportunities for future research.
KW  - 18F-DCFPL
KW  - Positronen-Emissions-Tomografie
KW  - Prostata
KW  - PSMA
KW  - Ganglia
KW  - Pitfall
KW  - PET
KW  - Tracer
KW  - Radiotracer
KW  - Imaging pitfalls
KW  - Prostate Cancer
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166971
SN  - 0914-7187
VL  - 31
IS  - 9
ER  - 
TY  - JOUR
A1  - Werner, Rudolf
A1  - Wakabayashi, Hiroshi
A1  - Bauer, Jochen
A1  - Schütz, Claudia
A1  - Zechmeister, Christina
A1  - Hayakawa, Nobuyuki
A1  - Javadi, Mehrbod S.
A1  - Lapa, Constantin
A1  - Jahns, Roland
A1  - Ergün, Süleyman
A1  - Jahns, Valerie
A1  - Higuchi, Takahiro
T1  - Longitudinal \(^{18}\)F-FDG PET imaging in a Rat Model of Autoimmune Myocarditis
JF  - European Heart Journal Cardiovascular Imaging
N2  - Aims: Although mortality rate is very high, diagnosis of acute myocarditis remains challenging with conventional tests. We aimed to elucidate the potential role of longitudinal 2-Deoxy-2-\(^{18}\)F-fluoro-D-glucose (\(^{18}\)F-FDG) positron emission tomography (PET) inflammation monitoring in a rat model of experimental autoimmune myocarditis.

Methods and results: Autoimmune myocarditis was induced in Lewis rats by immunizing with porcine cardiac myosin emulsified in complete Freund’s adjuvant. Time course of disease was assessed by longitudinal \(^{18}\)F-FDG PET imaging. A correlative analysis between in- and ex vivo \(^{18}\)F-FDG signalling and macrophage infiltration using CD68 staining was conducted. Finally, immunohistochemistry analysis of the cell-adhesion markers CD34 and CD44 was performed at different disease stages determined by longitudinal \(^{18}\)F-FDG PET imaging. After immunization, myocarditis rats revealed a temporal increase in 18F-FDG uptake (peaked at week 3), which was followed by a rapid decline thereafter. Localization of CD68 positive cells was well correlated with in vivo \(^{18}\)F-FDG PET signalling (R\(^2\) = 0.92) as well as with ex vivo 18F-FDG autoradiography (R\(^2\) = 0.9, P < 0.001, respectively). CD44 positivity was primarily observed at tissue samples obtained at acute phase (i.e. at peak 18F-FDG uptake), while CD34-positive staining areas were predominantly identified in samples harvested at both sub-acute and chronic phases (i.e. at \(^{18}\)F-FDG decrease).

Conclusion: \(^{18}\)F-FDG PET imaging can provide non-invasive serial monitoring of cardiac inflammation in a rat model of acute myocarditis.
KW  - positron emission tomography
KW  - Myokarditis
KW  - myocarditis
KW  - inflammation
KW  - 18F-FDG
KW  - PET
KW  - personalized treatment
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165601
SN  - 2047-2404
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Chen, Xinyu
A1  - Maya, Yoshifumi
A1  - Eissler, Christoph
A1  - Hirano, Mitsuru
A1  - Nose, Naoko
A1  - Wakabayashi, Hiroshi
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
T1  - The Impact of Ageing on 11C-Hydroxyephedrine Uptake in the Rat Heart
JF  - Scientific Reports
N2  - We aimed to explore the impact of ageing on 11C-Hydroxyephedrine (11C-HED) uptake in the healthy rat heart in a longitudinal setting. To investigate a potential cold mass effect, the influence of specific activity on cardiac 11C-HED uptake was evaluated: 11C-HED was synthesized by N-methylation of (−)-metaraminol as the free base (radiochemical purity >95%) and a wide range of specific activities (0.2–141.9 GBq/μmol) were prepared. \(^{11}\)C-HED (48.7±9.7MBq, ranged 0.2–60.4μg/kg cold mass) was injected in healthy Wistar Rats. Dynamic 23-frame PET images were obtained over 30 min. Time activity curves were generated for the blood input function and myocardial tissue. Cardiac 11C-HED retention index (%/min) was calculated as myocardial tissue activity at 20-30 min divided by the integral of the blood activity curves. Additionally, the impact of ageing on myocardial 11CHED uptake was investigated longitudinally by PET studies at different ages of healthy Wistar Rats. A dose-dependent reduction of cardiac 11C-HED uptake was observed: The estimated retention index as a marker of norepinephrine function decreased at a lower specific activity (higher amount of cold mass). This observed high affinity of 11C-HED to the neural norepinephrine transporter triggered a subsequent study: In a longitudinal setting, the 11C-HED retention index decreased with increasing age. An age-related decline of cardiac sympathetic innervation could be demonstrated. The herein observed cold mass effect might increase in succeeding scans and therefore, 11C-HED microPET studies should be planned with extreme caution if one single radiosynthesis is scheduled for multiple animals.
KW  - ageing
KW  - Positronen-Emissions-Tomografie
KW  - 11C-HED
KW  - 11C-Hydroxyephedrine
KW  - cardiac sympathetic nervous system
KW  - myocardial sympathetic innervation imaging
KW  - PET
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164826
SN  - 2281-5872
VL  - 8
IS  - 11120
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Ilhan, Harun
A1  - Lehner, Sebastian
A1  - Papp, László
A1  - Zsótér, Norbert
A1  - Schatka, Imke
A1  - Muegge, Dirk O.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Bartenstein, Peter
A1  - Bengel, Frank
A1  - Essler, Markus
A1  - Lapa, Constantin
A1  - Bundschuh, Ralph A.
T1  - Pre-therapy Somatostatin-Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy
T2  - Molecular Imaging and Biology
N2  - Purpose: Early identification of aggressive disease could improve decision-support in pancreatic neuroendocrine tumor (pNET) patients prior to peptide receptor radionuclide therapy (PRRT). The prognostic value of intratumoral textural features (TF) determined by baseline somatostatin receptor (SSTR)-PET before PRRT was analyzed.
Procedures: 31 patients with G1/G2 pNET were enrolled (G2, n=23/31). Prior to PRRT with [\(^{177}\)Lu]DOTATATE (mean, 3.6 cycles), baseline SSTR-PET/CT was performed. By segmentation of 162 (median per patient, 5) metastases, intratumoral TF were computed. The impact of conventional PET parameters  (SUV\(_{mean/max}\)), imaging-based TF as well as clinical parameters (Ki67, CgA) for prediction of both progression-free (PFS) and overall survival (OS) after PRRT was evaluated.
Results: Within a median follow-up of 3.7y, tumor progression was detected in 21 patients (median, 1.5y) and 13/31 deceased (median, 1.9y). In ROC analysis, the TF Entropy, reflecting derangement on a voxel-by-voxel level, demonstrated predictive capability for OS (cutoff=6.7, AUC=0.71, p=0.02). Of note, increasing Entropy could predict a longer survival (>6.7, OS=2.5y, 17/31), whereas less voxel-based derangement portended inferior outcome (<6.7, OS=1.9y, 14/31). These findings were supported in a G2 subanalysis (>6.9, OS=2.8y, 9/23 vs. <6.9, OS=1.9y, 14/23). Kaplan-Meier analysis revealed a significant distinction between high- and low-risk groups using Entropy (n=31, p<0.05). For those patients below the ROC-derived threshold, the relative risk of death after PRRT was 2.73 (n=31, p=0.04). Ki67 was negatively associated with PFS (p=0.002); however, SUVmean/max failed in prognostication (n.s.).
Conclusions: In contrast to conventional PET parameters, assessment of intratumoral heterogeneity demonstrated superior prognostic performance in pNET patients undergoing PRRT. This novel PET-based strategy of outcome prediction prior to PRRT might be useful for patient risk stratification.
KW  - Pancreas
KW  - Positronen-Emissions-Tomografie
KW  - PET
KW  - neuroendocrine tumor
KW  - tumor heterogeneity
KW  - [68Ga]
KW  - [177Lu]-DOTATATE/-DOTATOC
KW  - PET/CT
KW  - SSTR
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164624
UR  - https://link.springer.com/article/10.1007/s11307-018-1252-5
SN  - 1536-1632
N1  - This is a post-peer-review, pre-copyedit version of an article published in Molecular Imaging and Biology. The final authenticated version is available online at: http://dx.doi.org/s11307-018-1252-5
N1  - Die finale Version dieses Artikels steht unter https://doi.org/10.1007/s11307-018-1252-5 bzw. http://nbn-resolving.org/urn:nbn:de:bvb:20-opus-167168 open access zur Verfügung.
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Andree, Christian
A1  - Javadi, Mehrbod S.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Rowe, Steven P.
A1  - Pienta, Kenneth J.
T1  - A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging
JF  - Urology - The Gold Journal
N2  - No abstract available.
KW  - 18F-DCFPyL
KW  - PET
KW  - PSMA-PET
KW  - Positron Emission Tomography
KW  - Prostate Cancer
KW  - Virchow Node
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164632
SN  - 0090-4295
VL  - 117
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Chen, Xinyu
A1  - Hirano, Mitsuru
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
T1  - SPECT vs. PET in Cardiac Innervation Imaging: Clash of the Titans
JF  - Clinical and Translational Imaging
N2  - Purpose: We aim to provide an overview of the conventional single photon emission computed tomography (SPECT) and emerging positron emission tomography (PET) catecholamine analogue tracers for assessing myocardial nerve integrity, in particular focusing on \(^{18}\)F-labeled tracers. 
Results: Increasingly, the cardiac sympathetic nervous system (SNS) is being studied by non-invasive molecular imaging approaches. Forming the backbone of myocardial SNS imaging, the norepinephrine (NE) transporter at the sympathetic nerve terminal plays a crucial role for visualizing denervated myocardium: in particular, the single-photon-emitting NE analogue \(^{123}\)I-meta-Iodobenzylguanidine (\(^{123}\)I-mIBG) has demonstrated favorable results in the identification of patients at a high risk for cardiac death. However, cardiac neuronal PET agents offer several advantages inlcuding improved spatio-temporal resolution and intrinsic quantifiability. Compared to their \(^{11}\)C-labeled counterparts with a short half-life (20.4 min), novel \(^{18}\)F-labeled PET imaging agents to assess myocardial nerve integrity have the potential to revolutionize the field of SNS molecular imaging: The longer half-life of \(^{18}\)F (109.8 min) allows for more flexibility in the study design and delivery from central cyclotron facilities to smaller hospitals may lead to further cost reduction. A great deal of progress has been made by the first in-human studies of such \(^{18}\)F-labeled SNS imaging agents. Moreover, dedicated animal platforms open avenues for further insights into the handling of radiolabeled catecholamine analogues at the sympathetic nerve terminal. Conclusions: \(^{18}\)F-labeled imaging agents demonstrate key properties for mapping cardiac sympathetic nerve integrity and might outperform current SPECT-based or \(^{11}\)C-labeled tracers in the long run.
KW  - single photon emission computed tomography: sympathetic nerve
KW  - Positronen-Emissions-Tomografie
KW  - 18F-LMI1195
KW  - 11C-hydroxyephedrine
KW  - 123I-metaiodobenzylguanidine
KW  - positron emission tomography
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-163628
SN  - 2281-5872
ER  - 
TY  - JOUR
A1  - Werner, Rudolf
A1  - Solnes, Lilja
A1  - Javadi, Mehrbod
A1  - Weich, Alexander
A1  - Gorin, Michael
A1  - Pienta, Kenneth
A1  - Higuchi, Takahiro
A1  - Buck, Andreas
A1  - Pomper, Martin
A1  - Rowe, Steven
A1  - Lapa, Constantin
T1  - SSTR-RADS Version 1.0 as a Reporting System for SSTR-PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework
JF  - Journal of Nuclear Medicine
N2  - Reliable standards and criteria for somatostatin receptor (SSTR) positron emission tomography (PET) are still lacking. We herein propose a structured reporting system on a 5-point scale for SSTR-PET imaging, titled SSTR-RADS version 1.0, which might serve as a standardized assessment for both diagnosis and treatment planning in neuroendocrine tumors (NET). SSTR-RADS could guide the imaging specialist in interpreting SSTR-PET scans, facilitate communication with the referring clinician so that appropriate work-up for equivocal findings is pursued, and serve as a reliable tool for patient selection for planned Peptide Receptor Radionuclide Therapy.
KW  - Radionuclide Therapy
KW  - Standardisierung
KW  - Positronen-Emissions-Tomografie
KW  - 68Ga-DOTATATE/-TOC
KW  - Gastrointestinal
KW  - Neuroendocrine
KW  - Neuroendocrine Tumor
KW  - Oncology
KW  - GI
KW  - PET
KW  - PET/CT
KW  - PRRT
KW  - RADS
KW  - SSTR
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161298
SN  - 0161-5505
N1  - This  research  was  originally  published  in  JNM. Rudolf  A. Werner, Lilja  B. Solnes, Mehrbod Som  Javadi, Alexander  Weich, Michael A. Gorin, Kenneth J. Pienta, Takahiro  Higuchi, Andreas K. Buck, Martin G. Pomper, Steven P. Rowe, Constantin Lapa. SSTR-RADS Version 1.0 as   a Reporting System for SSTR-PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework. J. Nucl. Med. July 1, 2018, vol. 59, no. 7, 1085-1091. © SNMMI
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Kobayashi, Ryohei
A1  - Javadi, Mehrbod Som
A1  - Köck, Zoe
A1  - Wakabayashi, Hiroshi
A1  - Unterecker, Stefan
A1  - Nakajima, Kenichi
A1  - Lapa, Constantin
A1  - Menke, Andreas
A1  - Higuchi, Takahiro
T1  - Impact of Novel Antidepressants on Cardiac Metaiodobenzylguanidine (mIBG) Uptake: Experimental Studies in SK-N-SH Cells and Healthy Rabbits
JF  - Journal of Nuclear Medicine
N2  - Background: \(^{123}\)I-metaiodobenzylguanidine (mIBG) provides independent prognostic value for risk stratification among heart failure patients, but the use of concomitant medication should not impact its quantitative information. We aimed to evaluate the four most-prescribed antidepressants currently used as a first‑line treatment for patients with major depressive disorder (MDD) and their potential on altering mIBG imaging results. 
Methods: The inhibition effect of four different types of antidepressants (desipramine, escitalopram, venlafaxine and bupropion) for MDD treatment on \(^{131}\)I-mIBG uptake was assessed by in-vitro cell uptake assays using human neuroblastoma SK-N-SH cells. The half maximal inhibitory concentration (IC50) of tracer uptake was determined from dose-response curves. To evaluate the effects of IV pretreatment with desipramine (1.5 mg/kg) and escitalopram (2.5, 15 mg/kg) on mIBG cardiac uptake, in-vivo planar 123I-mIBG scans in healthy New Zealand White Rabbits were conducted. Results: The IC50 values of desipramine, escitalopram, venlafaxine and bupropion on \(^{131}\)I-mIBG cellular uptake were 11.9 nM, 7.5 μM, 4.92 μM, and 12.9 μM, respectively. At the maximum serum concentration (Cmax, as derived by previous clinical trials), the inhibition rates of 131I-mIBG uptake were 90.6 % for desipramine, 25.5 % for venlafaxine, 11.7 % for bupropion and 0.72 % for escitalopram. A low inhibition rate for escitalopram in the cell uptake study triggered investigation of an in-vivo rabbit model: with dosage considerably higher than clinical practice, the non-inhibitory effect of escitalopram was confirmed. Furthermore, pretreatment with desipramine led to a marked reduction of cardiac 123I-mIBG uptake. 
Conclusions: In the present in-vitro binding assay and in-vivo rabbit study, the selective-serotonin reuptake inhibitor escitalopram had no major impact on neuronal cardiac mIBG uptake within therapeutic dose ranges, while other types of first-line antidepressants for MDD treatment led to a significant decrease. These preliminary results warrant further confirmatory clinical trials regarding the reliability of cardiac mIBG imaging, in particular, if the patient’s neuropsychiatric status would not tolerate withdrawal of a potentially norepinephrine interfering antidepressant.
KW  - MDD
KW  - Antidepressants
KW  - depression
KW  - 123I-mIBG
KW  - antidepressant
KW  - cardiac sympathetic nerve system
KW  - major depressive disorder
KW  - myocardial sympathetic innervation imaging
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161280
SN  - 0161-5505
N1  - This research was originally published in JNM. Rudolf A. Werner, Ryohei Kobayashi, Mehrbod Som Javadi, Zoe Köck, Hiroshi Wakabayashi, Stefan Unterecker, Kenichi Nakajima, Constantin Lapa, Andreas Menke, Takahiro Higuchi. Impact of Novel Antidepressants on Cardiac Metaiodobenzylguanidine (mIBG) Uptake: Experimental Studies in SK-N-SH Cells and Healthy Rabbits. J. Nucl. Med. July 1, 2018, vol. 59, no. 7, 1099-1103. © SNMMI.
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Andree, Christian
A1  - Javadi, Mehrbod S.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Rowe, Steven P.
A1  - Pienta, Kenneth J.
T1  - A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging
T2  - Urology - The Gold Journal
N2  - No abstract available.
KW  - 18F-DCFPyL
KW  - Virchow Node
KW  - PSMA-PET
KW  - Virchow Node
KW  - Positron Emission Tomography
KW  - Prostate Cancer
KW  - PET
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161103
SN  - 0090-4295
N1  - This is the accepted manuscript of Rudolf Werner, Christian Andree, Mehrbod S. Javadi, Constantin Lapa, Andreas K. Buck, Takahiro Higuchi, Martin G. Pomper, Michael A.Gorin, Steven P.Rowe, Kenneth J. Pienta: A Voice From the Past: Re-Discovering the Virchow Node with PSMA-Targeted 18F-DCFPyL PET Imaging. Published in Urology 117(2018), p. 18-21. https://doi.org/10.1016/j.urology.2018.03.030
N1  - Die finale Version dieses Artikels steht unter https://doi.org/10.1016/j.urology.2018.03.030 oder https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-164632 open access zur Verfügung.
ER  - 
TY  - INPR
A1  - Nose, Naoko
A1  - Werner, Rudolf A.
A1  - Ueda, Yuichiro
A1  - Günther, Katharina
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
A1  - Fukushima, Kazuhito
A1  - Edenhofer, Frank
A1  - Higuchi, Takahiro
T1  - Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay
T2  - International Journal of Cardiology
N2  - Background: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. Material and Methods: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F-2-fluoro-2-deoxy-D-glucose (\(^{18}\)F-FDG) and \(^{125}\)I-β-methyl-iodophenyl-pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. Results: After cardiac differentiation of hiPSC, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. Conclusions: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications.
KW  - tracer
KW  - Stammzelle
KW  - induced pluripotent stem cells
KW  - cardiomyocytes
KW  - fatty acid
KW  - stem cell therapy
KW  - hiPSC-CM
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-163320
SN  - 0167-5273
ER  - 
TY  - JOUR
A1  - Wester, Hans Jürgen
A1  - Keller, Ulrich
A1  - Schottelius, Margret
A1  - Beer, Ambros
A1  - Philipp-Abbrederis, Kathrin
A1  - Hoffmann, Frauke
A1  - Šimeček, Jakub
A1  - Gerngross, Carlos
A1  - Lassmann, Michael
A1  - Herrmann, Ken
A1  - Pellegata, Natalia
A1  - Rudelius, Martina
A1  - Kessler, Horst
A1  - Schwaiger, Markus
T1  - Disclosing the CXCR4 expression in lymphoproliferative diseases by targeted molecular imaging
JF  - Theranostics
N2  - Chemokine ligand-receptor interactions play a pivotal role in cell attraction and cellular trafficking, both in normal tissue homeostasis and in disease. In cancer, chemokine receptor-4 (CXCR4) expression is an adverse prognostic factor. Early clinical studies suggest that targeting CXCR4 with suitable high-affinity antagonists might be a novel means for therapy. In addition to the preclinical evaluation of [\(^{68}\)Ga]Pentixafor in mice bearing human lymphoma xenografts as an exemplary CXCR4-expressing tumor entity, we report on the first clinical applications of [\(^{68}\)Ga]Pentixafor-Positron Emission Tomography as a powerful method for CXCR4 imaging in cancer patients. [\(^{68}\)Ga]Pentixafor binds with high affinity and selectivity to human CXCR4 and exhibits a favorable dosimetry. [\(^{68}\)Ga]Pentixafor-PET provides images with excellent specificity and contrast. This non-invasive imaging technology for quantitative assessment of CXCR4 expression allows to further elucidate the role of CXCR4/CXCL12 ligand interaction in the pathogenesis and treatment of cancer, cardiovascular diseases and autoimmune and inflammatory disorders.
KW  - acute myeloid leukemia
KW  - prognostic value
KW  - therapeutic target
KW  - chemokine receptor
KW  - CXCR4
KW  - lymphoma
KW  - in vivo imaging
KW  - positron emission tomography
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144537
VL  - 5
IS  - 6
ER  - 
TY  - CHAP
A1  - Werner, Rudolf A.
A1  - Chen, Xinyu
A1  - Hirano, Mitsuru
A1  - Nose, Naoko
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
T1  - The Impact of Ageing on [\(^{11}\)C]meta-Hydroxyephedrine Uptake in the Rat Heart
T2  - Journal of Nuclear Medicine
N2  - No abstract available.
KW  - Positronen-Emissions-Tomografie
KW  - moycardial sympathetic innervation
KW  - Positronen-Emissions-Tomografie
KW  - positron emission tomography
KW  - PET
KW  - 11C-HED
KW  - hydroxyephedrine
KW  - ageing
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162228
UR  - http://jnm.snmjournals.org/content/59/supplement_1/100.abstract
SN  - 0161-5505
VL  - 59
IS  - Supplement No 1
ER  - 
TY  - CHAP
A1  - Werner, Rudolf A.
A1  - Marcus, Charles
A1  - Sheikhbahaei, Sara
A1  - Higuchi, Takahiro
A1  - Solnes, Lilja B.
A1  - Rowe, Steven P.
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
T1  - The Impact of Ageing on Dopamine Transporter Imaging
T2  - Journal of Nuclear Medicine
N2  - No abstract available.
KW  - Parkinson-Krankheit
KW  - Parkinson
KW  - Parkinson Disease
KW  - DaTscan
KW  - Ioflupane
KW  - SPECT
KW  - molecular imaging
KW  - ageing
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162213
UR  - http://jnm.snmjournals.org/content/59/supplement_1/1646.abstract
SN  - 0161-5505
N1  - This research was originally published in JNM. Rudolf A. Werner, Charles Marcus, Sara Sheikhbahaei, Takahiro Higuchi, Lilja B. Solnes, Steven P. Rowe, Andreas K. Buck, Constantin Lapa, Mehrbod S. Javadi. The Impact of Ageing on Dopamine Transporter Imaging. J Nucl Med. May 1, 2018; vol. 59 no. supplement 1:1646. © SNMMI.
VL  - 59
IS  - Supplement No 1
SP  - 1646
ER  -