@article{GargWernerChungetal.2022, author = {Garg, Tushar and Werner, Rudolf A. and Chung, Hyun Woo and Khatri, Wajahat and Pienta, Kenneth J. and Pomper, Martin G. and Gorin, Michael A. and Saad, Elie and Rowe, Steven P.}, title = {Association of true positivity with serum prostate-specific antigen levels and other clinical factors in indeterminate PSMA-RADS-3A lesions identified on \(^{18}\)F-DCFPyL PET/CT scans}, series = {Tomography}, volume = {8}, journal = {Tomography}, number = {6}, issn = {2379-139X}, doi = {10.3390/tomography8060220}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290510}, pages = {2639 -- 2647}, year = {2022}, abstract = {The use of prostate-specific membrane antigen targeted PET imaging for the evaluation of prostate cancer has increased significantly in the last couple of decades. When evaluating these imaging findings based on the PSMA reporting and data system version 1.0, which categorize lesions based on their likelihood of prostate cancer involvement, PSMA-RADS-3A lesions are commonly seen, which are indeterminate for the presence of disease. A total of 28 patients with 171 PSMA-RADS-3A lesions on \(^{18}\)F-DCFPyL PET/CT scans from June 2016 to May 2017 who had follow-up cross-sectional imaging over time were included in this study. The PSA levels of patients with PSMA-RADS-3A lesions were categorized into four groups, 0-0.2, 0.2-1, 1-2, and >2 ng/mL. The pre-operative Gleason score of these patients was categorized into two groups, Gleason score < 7 or ≥7. The median age for these patients was 72.5 years (range 59-81). The median PSA value for patients with positive lesions was significantly higher than those with negative lesions (5.8 ng/mL vs. 0.2 ng/mL, p < 0.0001). The lesion positivity rate was significantly higher in patients with PSA > 1 ng/mL (18.2\% vs. 81.9\%, p < 0.001). On ROC analysis, the highest classification accuracy was seen at PSA ≥ 0.6 ng/mL of 80.12\% (95\% CI = 73.69-86.16\%), and the area under the curve was 71.32\% (95\% CI = 61.9-80.7\%, p < 0.0001). A total of 96.4\% (108/112) of patients with positive lesions and 86.4\% (51/59) of patients with negative lesions had a PSMA-RADS-4/5 lymph node on the initial \(^{18}\)F-DCFPyL PET/CT scan (p = 0.02). In patients with a Gleason score ≥ 7, the presence of positive PSMA-RADS-3A lesions was higher, compared to negative PSMA-RADS-3A lesions (p = 0.049). Higher PSA levels in patients with PSMA-RADS-3A lesions can point towards the presence of true positivity. PSA levels may be considered in deciding whether to call an indeterminate lesion on PSMA PET.}, language = {en} } @article{HartrampfWeinzierlSeitzetal.2022, author = {Hartrampf, Philipp E. and Weinzierl, Franz-Xaver and Seitz, Anna Katharina and K{\"u}bler, Hubert and Essler, Markus and Buck, Andreas K. and Werner, Rudolf A. and Bundschuh, Ralph A.}, title = {Any decline in prostate-specific antigen levels identifies survivors scheduled for prostate-specific membrane antigen-directed radioligand therapy}, series = {The Prostate}, volume = {82}, journal = {The Prostate}, number = {14}, doi = {10.1002/pros.24414}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318766}, pages = {1406 -- 1412}, year = {2022}, abstract = {Background Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) is increasingly incorporated in the therapeutic algorithm of patients with metastatic castration-resistant prostate cancer (mCRPC). We aimed to elucidate the predictive performance of early biochemical response for overall survival (OS). Materials and Methods In this bicentric analysis, we included 184 mCRPC patients treated with \(^{177}\)Lu-PSMA RLT. Response to treatment was defined as decrease in prostate-specific antigen (PSA) levels 8 weeks after the first cycle of RLT (any decline or >50\% according to Prostate Cancer Working Group 3). OS of responders and nonresponders was then compared using Kaplan-Meier curves and log-rank comparison. Results A total of 114/184 patients (62.0\%) showed any PSA decline (PSA response >50\%, 55/184 [29.9\%]). For individuals exhibiting a PSA decline >50\%, OS of 19 months was significantly longer relative to nonresponders (13 months; hazard ratio of death [HR] = 0.64, 95\% confidence interval [95\% CI] = 0.44-0.93; p = 0.02). However, the difference was even more pronounced for any PSA decline, with an OS of 19 months in responders, but only 8 months in nonresponders (HR = 0.39, 95\% CI = 0.25-0.60; p < 0.001). Conclusions In mCRPC patients scheduled for RLT, early biochemical response was tightly linked to prolonged survival, irrespective of the magnitude of PSA decline. As such, even in patients with PSA decrease of less than 50\%, RLT should be continued.}, language = {en} } @phdthesis{Viering2023, author = {Viering, Oliver}, title = {\(^{18}\)F-Fluordesoxyglucose- und \(^{11}\)C-Methionin-PET/CT bei Patient/-innen mit neu diagnostiziertem Multiplen Myelom: Ein Vergleich volumenbasierter PET-Biomarker}, doi = {10.25972/OPUS-31803}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318032}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {11C-Methionin (11C-MET) ist ein alternatives Radiopharmakon f{\"u}r die Positronen-Emissions-Tomographie (PET) zur Beurteilung der Krankheitsaktivit{\"a}t bei Patient/-innen mit Multiplem Myelom (MM). Fr{\"u}he Daten legen eine h{\"o}here Sensitivit{\"a}t und Spezifit{\"a}t als bei dem bisherigen Standardtracer 18F-Fluordesoxyglucose (18F-FDG) nahe. Es fehlen bislang jedoch Untersuchungen, welche die neuen, aus PET-Daten abgeleiteten Parameter „metabolic tumor volume" (MTV) und „total lesion glycolysis / total lesion methionin uptake" (TLG/TLMU) in diesen Vergleich miteinbeziehen. In fr{\"u}heren Studien konnte bereits eine prognostische Aussagekraft dieser neuen Imaging Parameter f{\"u}r die 18F-FDG-PET/CT gezeigt werden. Das Ziel dieser bizentrischen Studie war es, die sich im Rahmen bisheriger Studienergebnisse andeutende {\"U}berlegenheit von 11C-MET f{\"u}r das Staging des MM zu {\"u}berpr{\"u}fen und seine Eignung f{\"u}r die Bewertung von metabolischen Imaging Parametern im Vergleich zu 18F-FDG zu untersuchen. Zweiundzwanzig Patient/-innen mit neu diagnostiziertem unbehandelten MM, davon 15 Patient/-innen des Universit{\"a}tsklinikums W{\"u}rzburg und sieben Patient/-innen der Clinica Universidad de Navarra in Pamplona, die eine doppelte PET/CT-Bildgebung unter Verwendung der beiden Tracer 11C-MET und 18F-FDG innerhalb eines Zeitraums von maximal 14 Tagen erhalten hatten, wurden retrospektiv durch den Doktoranden (Oliver Viering) sowie eine nuklearmedizinische Assistenz{\"a}rztin (Maria I. Morales-Lozano) und im Anschluss durch je eine PET/CT-Expert/-in des Universit{\"a}tsklinikums W{\"u}rzburg (Constantin Lapa) und der Clinica Universidad de Navarra (Maria J. Garcia-Velloso) untersucht. Hierf{\"u}r wurden die 18F-FDG- und 11C-MET-PET/CT-Aufnahmen einer dreidimensionalen Analyse mit Hilfe des "PET/CT-Viewer Beth Israel for FIJI" unterzogen. Diese open source Software erm{\"o}glichte die Berechnung von SUVmean, SUVmax und SUVpeak sowie der neuen Imaging Biomarker MTV und TLG/TLMU. Die genannten PET-Parameter wurden mit klinischen und laborchemischen Parametern (H{\"a}moglobin, Calcium, Kreatinin, CRP, β2-Mikroglobulin, Albumin, M-Gradient/M-Protein, Knochenmarkinfiltration, LDH, freier Leichtketten-quotient, R-ISS, zytogenetisches Risiko) korreliert, welche in fr{\"u}heren Studien als prognostisch relevante Parameter der Myelom-Erkrankung identifiziert worden waren. Bei elf der 22 Patient/-innen (50 \%) wurden mithilfe von 11C-MET mehr fokale L{\"a}sionen als mit 18F-FDG nachgewiesen (p < 0,01), daneben konnte bei einer gr{\"o}ßeren Zahl von Patient/-innen eine diffuse Knochenmarkinfiltration durch die malignen Plasmazellen identifiziert werden (11C-MET: 19, 18F-FDG: 12). Sowohl die SUV-Parameter (SUVmean, SUVmax und SUVpeak) als auch die neuen Imaging Parameter (TMTV und TLG/TLMU) waren bei der 11C-MET- signifikant h{\"o}her als bei der 18F-FDG-PET/CT (p < 0,05). In Bezug auf die neuen Imaging Parameter zeigten sich f{\"u}r 11C-MET h{\"a}ufiger signifikante Korrelationen mit den prognostisch relevanten klinischen und laborchemischen Parametern als f{\"u}r 18F-FDG. Bei TMTV konnten f{\"u}r die 11C-MET-PET/CT signifikante Korrelationen f{\"u}r β2-Mikroglobulin (p = 0,006), die M-Komponente (p = 0,003), den Grad der Knochenmarkinfiltration (p = 0,007) und das Serum-H{\"a}moglobin (p = 0,016) gefunden werden, wohingegen sich bei 18F-FDG lediglich eine signifikante Korrelation f{\"u}r β2-Mikroglobulin (p = 0,044) zeigte. In Bezug auf die TLG/TLMU konnten bei 18F-FDG keine signifikanten Korrelationen zwischen TLG und den klinischen und laborchemischen Parametern nachgewiesen werden. Bei 11C-MET zeigten sich hingegen signifikante Korrelationen zwischen dem TLMU und der Kalzium-Konzentration im Serum (p = 0,028), dem β2-Mikroglobulin (p = 0,047), der M-Komponente (p = 0,033) und dem Grad der Knochenmarkinfiltration (p = 0,041). Trotz zahlreicher Limitationen dieser Arbeit, wie etwa der geringen Patientenzahl und des retrospektiven Charakters der Auswertung bekr{\"a}ftigt auch diese Studie in {\"U}bereinstimmung mit den bisherigen Studienergebnissen, dass 11C-MET im Vergleich zu 18F-FDG ein sensitiverer Marker f{\"u}r die Beurteilung der Myelom-Tumorlast sein k{\"o}nnte. Eine Untersuchung der prognostischen Aussagekraft von 11C-MET in Bezug auf progressionsfreies- und Gesamt{\"u}berleben im Zuge der prim{\"a}ren Bildgebung der Erkrankung war aufgrund der kurzen Nachbeobachtungszeit und der Heterogenit{\"a}t der Behandlung, welche die Patient/-innen im Anschluss an die Staging-Untersuchungen erhalten hatten, nicht m{\"o}glich und muss im Rahmen zuk{\"u}nftiger, insbesondere prospektiver Studien weiter untersucht werden.}, subject = {Plasmozytom}, language = {de} } @article{RascheKumarGershneretal.2019, author = {Rasche, Leo and Kumar, Manoj and Gershner, Grant and Samant, Rohan and Van Hemert, Rudy and Heidemeier, Anke and Lapa, Constantin and Bley, Thorsten and Buck, Andreas and McDonald, James and Hillengass, Jens and Epstein, Joshua and Thanendrarajan, Sharmilan and Schinke, Carolina and van Rhee, Frits and Zangari, Maurizio and Barlogie, Bart and Davies, Faith E. and Morgan, Gareth J. and Weinhold, Niels}, title = {Lack of Spleen Signal on Diffusion Weighted MRI is associated with High Tumor Burden and Poor Prognosis in Multiple Myeloma: A Link to Extramedullary Hematopoiesis?}, series = {Theranostics}, volume = {9}, journal = {Theranostics}, number = {16}, doi = {10.7150/thno.33289}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224982}, pages = {4756-4763}, year = {2019}, abstract = {Due to the low frequency of abnormalities affecting the spleen, this organ is often overlooked during radiological examinations. Here, we report on the unexpected finding, that the spleen signal on diffusion-weighted MRI (DW-MRI) is associated with clinical parameters in patients with plasma cell dyscrasias. Methods: We investigated the spleen signal on DW-MRI together with clinical and molecular parameters in 295 transplant-eligible newly diagnosed Multiple Myeloma (NDMM) patients and in 72 cases with monoclonal gammopathy of undetermined significance (MGUS). Results: Usually, the spleen is the abdominal organ with the highest intensities on DW-MRI. Yet, significant signal loss on DW-MRI images was seen in 71 of 295 (24\%) NDMM patients. This phenomenon was associated with the level of bone marrow plasmacytosis (P=1x10(-10)) and International Staging System 3 (P=0.0001) but not with gain(1q), and del(17p) or plasma cell gene signatures. The signal was preserved in 72 individuals with monoclonal gammopathy of undetermined significance and generally re-appeared in MM patients responding to treatment, suggesting that lack of signal reflects increased tumor burden. While absence of spleen signal in MM patients with high risk disease defined a subgroup with very poor outcome, re-appearance of the spleen signal after autologous stem cell transplantation was seen in patients with improved outcome. Our preliminary observation suggests that extramedullary hematopoiesis in the spleen is a factor that modifies the DW-MRI signal of this organ. Conclusions: The DW-MRI spleen signal is a promising marker for tumor load and provides prognostic information in MM.}, language = {en} } @article{ZhouDierksKertelsetal.2020, author = {Zhou, Xiang and Dierks, Alexander and Kertels, Olivia and Kircher, Malte and Schirbel, Andreas and Samnick, Samuel and Buck, Andreas K. and Knorz, Sebastian and B{\"o}ckle, David and Scheller, Lukas and Messerschmidt, Janin and Barakat, Mohammad and Kort{\"u}m, K. Martin and Rasche, Leo and Einsele, Hermann and Lapa, Constantin}, title = {18F-FDG, 11C-Methionine, and 68Ga-Pentixafor PET/CT in patients with smoldering multiple myeloma: imaging pattern and clinical features}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {8}, issn = {2072-6694}, doi = {10.3390/cancers12082333}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211240}, year = {2020}, abstract = {This study aimed to explore the correlation between imaging patterns and clinical features in patients with smoldering multiple myeloma (SMM) who simultaneously underwent 18F-FDG, 11C-Methionine, and 68Ga-Pentixafor positron emission tomography/computed tomography (PET/CT). We retrieved and analyzed clinical characteristics and PET imaging data of 10 patients with SMM. We found a significant correlation between bone marrow (BM) plasma cell (PC) infiltration and mean standardized uptake values (SUV\(_{mean}\)) of lumbar vertebrae L2-L4 on 11C-Methionine PET/CT scans (r = 0.676, p = 0.031) and 68Ga-Pentixafor PET/CT scans (r = 0.839, p = 0.002). However, there was no significant correlation between BM involvement and SUV\(_{mean}\) of lumbar vertebrae L2-L4 on 18F-FDG PET/CT scans (r = 0.558, p = 0.093). Similarly, mean target-to-background ratios (TBR\(_{mean}\)) of lumbar vertebrae L2-L4 also correlated with bone marrow plasma cell (BMPC) infiltration in 11C-Methionine PET/CT (r = 0.789, p = 0.007) and 68Ga-Pentixafor PET/CT (r = 0.724, p = 0.018) PET/CT. In contrast, we did not observe a significant correlation between BMPC infiltration rate and TBR\(_{mean}\) in 18F-FDG PET/CT (r = 0.355, p = 0.313). Additionally, on 11C-Methionine PET/CT scans, we found a significant correlation between BMPC infiltration and TBR\(_{max}\) of lumbar vertebrae L2-L4 (r = 0.642, p = 0.045). In conclusion, 11C-Methionine and 68Ga-Pentixafor PET/CT demonstrate higher sensitivity than 18F-FDG PET/CT in detecting BM involvement in SMM.}, language = {en} } @article{WernerHiguchiNoseetal.2022, author = {Werner, Rudolf A. and Higuchi, Takahiro and Nose, Naoko and Toriumi, Fujio and Matsusaka, Yohji and Kuji, Ichiei and Kazuhiro, Koshino}, title = {Generative adversarial network-created brain SPECTs of cerebral ischemia are indistinguishable to scans from real patients}, series = {Scientific reports}, volume = {12}, journal = {Scientific reports}, doi = {10.1038/s41598-022-23325-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300757}, year = {2022}, abstract = {Deep convolutional generative adversarial networks (GAN) allow for creating images from existing databases. We applied a modified light-weight GAN (FastGAN) algorithm to cerebral blood flow SPECTs and aimed to evaluate whether this technology can generate created images close to real patients. Investigating three anatomical levels (cerebellum, CER; basal ganglia, BG; cortex, COR), 551 normal (248 CER, 174 BG, 129 COR) and 387 pathological brain SPECTs using N-isopropyl p-I-123-iodoamphetamine (123I-IMP) were included. For the latter scans, cerebral ischemic disease comprised 291 uni- (66 CER, 116 BG, 109 COR) and 96 bilateral defect patterns (44 BG, 52 COR). Our model was trained using a three-compartment anatomical input (dataset 'A'; including CER, BG, and COR), while for dataset 'B', only one anatomical region (COR) was included. Quantitative analyses provided mean counts (MC) and left/right (LR) hemisphere ratios, which were then compared to quantification from real images. For MC, 'B' was significantly different for normal and bilateral defect patterns (P < 0.0001, respectively), but not for unilateral ischemia (P = 0.77). Comparable results were recorded for LR, as normal and ischemia scans were significantly different relative to images acquired from real patients (P ≤ 0.01, respectively). Images provided by 'A', however, revealed comparable quantitative results when compared to real images, including normal (P = 0.8) and pathological scans (unilateral, P = 0.99; bilateral, P = 0.68) for MC. For LR, only uni- (P = 0.03), but not normal or bilateral defect scans (P ≥ 0.08) reached significance relative to images of real patients. With a minimum of only three anatomical compartments serving as stimuli, created cerebral SPECTs are indistinguishable to images from real patients. The applied FastGAN algorithm may allow to provide sufficient scan numbers in various clinical scenarios, e.g., for "data-hungry" deep learning technologies or in the context of orphan diseases.}, language = {en} } @article{LisowskiTroemelLutyjetal.2022, author = {Lisowski, Dominik and Tr{\"o}mel, Jannik and Lutyj, Paul and Lewitzki, Victor and Hartrampf, Philipp E. and Polat, B{\"u}lent and Flentje, Michael and Tamihardja, J{\"o}rg}, title = {Health-related quality of life and clinical outcome after radiotherapy of patients with intracranial meningioma}, series = {Scientific Reports}, volume = {12}, journal = {Scientific Reports}, doi = {10.1038/s41598-022-24192-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301233}, year = {2022}, abstract = {This retrospective, single-institutional study investigated long-term outcome, toxicity and health-related quality of life (HRQoL) in meningioma patients after radiotherapy. We analyzed the data of 119 patients who received radiotherapy at our department from 1997 to 2014 for intracranial WHO grade I-III meningioma. Fractionated stereotactic radiotherapy (FSRT), intensity modulated radiotherapy (IMRT) or radiosurgery radiation was applied. The EORTC QLQ-C30 and QLQ-BN20 questionnaires were completed for assessment of HRQoL. Overall survival (OS) for the entire study group was 89.6\% at 5 years and 75.9\% at 10 years. Local control (LC) at 5 and 10 years was 82.4\% and 73.4\%, respectively. Local recurrence was observed in 22 patients (18.5\%). Higher grade acute and chronic toxicities were observed in seven patients (5.9\%) and five patients (4.2\%), respectively. Global health status was rated with a mean of 59.9 points (SD 22.3) on QLQ-C30. In conclusion, radiotherapy resulted in very good long-term survival and tumor control rates with low rates of severe toxicities but with a deterioration of long-term HRQoL.}, language = {en} } @article{WernerHabachaLuetjeetal.2022, author = {Werner, Rudolf A. and Habacha, Bil{\^e}l and L{\"u}tje, Susanne and Bundschuh, Lena and Higuchi, Takahiro and Hartrampf, Philipp and Serfling, Sebastian E. and Derlin, Thorsten and Lapa, Constantin and Buck, Andreas K. and Essler, Markus and Pienta, Kenneth J. and Eisenberger, Mario A. and Markowski, Mark C. and Shinehouse, Laura and AbdAllah, Rehab and Salavati, Ali and Lodge, Martin A. and Pomper, Martin G. and Gorin, Michael A. and Bundschuh, Ralph A. and Rowe, Steven P.}, title = {High SUVs Have More Robust Repeatability in Patients with Metastatic Prostate Cancer: Results from a Prospective Test-Retest Cohort Imaged with \(^{18}\)F-DCFPyL}, series = {Molecular Imaging}, volume = {2022}, journal = {Molecular Imaging}, doi = {10.1155/2022/7056983}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300748}, year = {2022}, abstract = {No abstract available.}, language = {en} } @article{WenzArndtSamnick2022, author = {Wenz, Jan and Arndt, Felix and Samnick, Samuel}, title = {A new concept for the production of \(^{11}\)C-labelled radiotracers}, series = {EJNMMI Radiopharmacy and Chemistry}, volume = {7}, journal = {EJNMMI Radiopharmacy and Chemistry}, doi = {10.1186/s41181-022-00159-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300731}, year = {2022}, abstract = {Background The GMP-compliant production of radiopharmaceuticals has been performed using disposable units (cassettes) with a dedicated synthesis module. To expand this "plug 'n' synthesize" principle to a broader scope of modules we developed a pressure controlled setup that offers an alternative to the usual stepper motor controlled rotary valves. The new concept was successfully applied to the synthesis of N-methyl-[\(^{11}\)C]choline, L-S-methyl-[\(^{11}\)C]methionine and [11C]acetate. Results The target gas purification of cyclotron produced [\(^{11}\)C]CO\(_2\) and subsequent conversion to [\(^{11}\)C]MeI was carried out on a TRACERlab Fx C Pro module. The labelling reactions were controlled with a TRACERlab Fx FE module. With the presented modular principle we were able to produce N-methyl-[\(^{11}\)C]choline and L-S-methyl-[\(^{11}\)C]methionine by loading a reaction loop with neat N,N'-dimethylaminoethanol (DMAE) or an ethanol/water mixture of NaOH and L-homocysteine (L-HC), respectively and a subsequent reaction with [\(^{11}\)C]MeI. After 18 min N-methyl-[\(^{11}\)C]choline was isolated with 52\% decay corrected yield and a radiochemical purity of > 99\%. For L-S-methyl-[\(^{11}\)C]methionine the total reaction time was 19 min reaction, yielding 25\% of pure product (> 97\%). The reactor design was used as an exemplary model for the technically challenging [\(^{11}\)C]acetate synthesis. The disposable unit was filled with 1 mL MeMgCl (0.75 M) in tetrahydrofuran (THF) bevore [\(^{11}\)C]CO\(_2\) was passed through. After complete release of [\(^{11}\)C]CO\(_2\) the reaction mixture was quenched with water and guided through a series of ion exchangers (H\(^+\), Ag\(^+\) and OH\(^-\)). The product was retained on a strong anion exchanger, washed with water and finally extracted with saline. The product mixture was acidified and degassed to separate excess [\(^{11}\)C]CO\(_2\) before dispensing. Under these conditions the total reaction time was 18 ± 2 min and pure [\(^{11}\)C]acetate (n = 10) was isolated with a decay corrected yield of 51 ± 5\%. Conclusion Herein, we described a novel single use unit for the synthesis of carbon-11 labelled tracers for preclinical and clinical applications of N-methyl-[\(^{11}\)C]choline, L-S-methyl-[\(^{11}\)C]methionine and [11C]acetate.}, language = {en} } @article{LeubeGustafssonLassmannetal.2022, author = {Leube, Julian and Gustafsson, Johan and Lassmann, Michael and Salas-Ramirez, Maikol and Tran-Gia, Johannes}, title = {Analysis of a deep learning-based method for generation of SPECT projections based on a large Monte Carlo simulated dataset}, series = {EJNMMI Physics}, volume = {9}, journal = {EJNMMI Physics}, issn = {2197-7364}, doi = {10.1186/s40658-022-00476-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300697}, year = {2022}, abstract = {Background In recent years, a lot of effort has been put in the enhancement of medical imaging using artificial intelligence. However, limited patient data in combination with the unavailability of a ground truth often pose a challenge to a systematic validation of such methodologies. The goal of this work was to investigate a recently proposed method for an artificial intelligence-based generation of synthetic SPECT projections, for acceleration of the image acquisition process based on a large dataset of realistic SPECT simulations. Methods A database of 10,000 SPECT projection datasets of heterogeneous activity distributions of randomly placed random shapes was simulated for a clinical SPECT/CT system using the SIMIND Monte Carlo program. Synthetic projections at fixed angular increments from a set of input projections at evenly distributed angles were generated by different u-shaped convolutional neural networks (u-nets). These u-nets differed in noise realization used for the training data, number of input projections, projection angle increment, and number of training/validation datasets. Synthetic projections were generated for 500 test projection datasets for each u-net, and a quantitative analysis was performed using statistical hypothesis tests based on structural similarity index measure and normalized root-mean-squared error. Additional simulations with varying detector orbits were performed on a subset of the dataset to study the effect of the detector orbit on the performance of the methodology. For verification of the results, the u-nets were applied to Jaszczak and NEMA physical phantom data obtained on a clinical SPECT/CT system. Results No statistically significant differences were observed between u-nets trained with different noise realizations. In contrast, a statistically significant deterioration was found for training with a small subset (400 datasets) of the 10,000 simulated projection datasets in comparison with using a large subset (9500 datasets) for training. A good agreement between synthetic (i.e., u-net generated) and simulated projections before adding noise demonstrates a denoising effect. Finally, the physical phantom measurements show that our findings also apply for projections measured on a clinical SPECT/CT system. Conclusion Our study shows the large potential of u-nets for accelerating SPECT/CT imaging. In addition, our analysis numerically reveals a denoising effect when generating synthetic projections with a u-net. Clinically interesting, the methodology has proven robust against camera orbit deviations in a clinically realistic range. Lastly, we found that a small number of training samples (e.g., ~ 400 datasets) may not be sufficient for reliable generalization of the u-net.}, language = {en} } @article{PrietoGarciaHartmannReisslandetal.2022, author = {Prieto-Garcia, Cristian and Hartmann, Oliver and Reissland, Michaela and Braun, Fabian and Bozkurt, S{\"u}leyman and Pahor, Nikolett and Fuss, Carmina and Schirbel, Andreas and Sch{\"u}lein-V{\"o}lk, Christina and Buchberger, Alexander and Calzado Canale, Marco A. and Rosenfeldt, Mathias and Dikic, Ivan and M{\"u}nch, Christian and Diefenbacher, Markus E.}, title = {USP28 enables oncogenic transformation of respiratory cells, and its inhibition potentiates molecular therapy targeting mutant EGFR, BRAF and PI3K}, series = {Molecular Oncology}, volume = {16}, journal = {Molecular Oncology}, number = {17}, doi = {10.1002/1878-0261.13217}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312777}, pages = {3082-3106}, year = {2022}, abstract = {Oncogenic transformation of lung epithelial cells is a multistep process, frequently starting with the inactivation of tumour suppressors and subsequent development of activating mutations in proto-oncogenes, such as members of the PI3K or MAPK families. Cells undergoing transformation have to adjust to changes, including altered metabolic requirements. This is achieved, in part, by modulating the protein abundance of transcription factors. Here, we report that the ubiquitin carboxyl-terminal hydrolase 28 (USP28) enables oncogenic reprogramming by regulating the protein abundance of proto-oncogenes such as c-JUN, c-MYC, NOTCH and ∆NP63 at early stages of malignant transformation. USP28 levels are increased in cancer compared with in normal cells due to a feed-forward loop, driven by increased amounts of oncogenic transcription factors such as c-MYC and c-JUN. Irrespective of oncogenic driver, interference with USP28 abundance or activity suppresses growth and survival of transformed lung cells. Furthermore, inhibition of USP28 via a small-molecule inhibitor resets the proteome of transformed cells towards a 'premalignant' state, and its inhibition synergizes with clinically established compounds used to target EGFR\(^{L858R}\)-, BRAF\(^{V600E}\)- or PI3K\(^{H1047R}\)-driven tumour cells. Targeting USP28 protein abundance at an early stage via inhibition of its activity is therefore a feasible strategy for the treatment of early-stage lung tumours, and the observed synergism with current standard-of-care inhibitors holds the potential for improved targeting of established tumours.}, language = {en} } @article{LassmannEberlein2023, author = {Lassmann, Michael and Eberlein, Uta}, title = {Comparing absorbed doses and radiation risk of the α-emitting bone-seekers [\(^{223}\)Ra]RaCl\(_2\) and [\(^{224}\)Ra]RaCl\(_2\)}, series = {Frontiers in Medicine}, volume = {9}, journal = {Frontiers in Medicine}, issn = {2296-858X}, doi = {10.3389/fmed.2022.1057373}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301509}, year = {2023}, abstract = {[\(^{223}\)Ra]RaCl\(_2\) and [\(^{224}\)Ra]RaCl\(_2\) are bone seekers, emitting high LET, and short range (< 100 μm) alpha-particles. Both radionuclides show similar decay properties; the total alpha energies are comparable (\(^{223}\)Ra: ≈28 MeV, \(^{224}\)Ra: ≈26 MeV). [\(^{224}\)Ra]RaCl\(_2\) has been used from the mid-1940s until 1990 for treating different bone and joint diseases with activities of up to approximately 50 MBq [\(^{224}\)Ra]RaCl\(_2\). In 2013 [\(^{223}\)Ra]RaCl\(_2\) obtained marketing authorization by the FDA and by the European Union for the treatment of metastatic prostate cancer with an activity to administer of 0.055 MBq per kg body weight for six cycles. For intravenous injections in humans a model calculation using the biokinetic model of ICRP67 shows a ratio of organ absorbed dose coefficients (\(^{224}\)Ra:\(^{223}\)Ra) between 0.37 (liver) and 0.97 except for the kidneys (2.27) and blood (1.57). For the red marrow as primary organ-at-risk, the ratio is 0.57. The differences are mainly caused be the differing half-lives of the decay products of both radium isotopes. Both radionuclides show comparable DNA damage patterns in peripheral blood mononuclear cells after internal ex-vivo irradiation. Data on the long-term radiation-associated side effects are only available for treatment with [\(^{224}\)Ra]RaCl\(_2\). Two epidemiological studies followed two patient groups treated with [\(^{224}\)Ra]RaCl\(_2\) for more than 25 years. One of them was the "Spiess study", a cohort of 899 juvenile patients who received several injections of [\(^{224}\)Ra]RaCl\(_2\) with a mean specific activity of 0.66 MBq/kg. Another patient group of ankylosing spondylitis patients was treated with 10 repeated intravenous injections of [\(^{224}\)Ra]RaCl\(_2\), 1 MBq each, 1 week apart. In total 1,471 of these patients were followed-up in the "Wick study". In both studies, an increased cancer mortality by leukemia and solid cancers was observed. Similar considerations on long-term effects likely apply to [\(^{223}\)Ra]RaCl\(_2\) as well since the biokinetics are similar and the absorbed doses in the same range. However, this increased risk will most likely not be observed due to the much shorter life expectancy of prostate cancer patients treated with [\(^{223}\)Ra]RaCl\(_2\).}, language = {en} } @article{TamihardjaZehnerHartrampfetal.2022, author = {Tamihardja, J{\"o}rg and Zehner, Leonie and Hartrampf, Philipp E. and Cirsi, Sinan and Wegener, Sonja and Buck, Andreas K. and Flentje, Michael and Polat, B{\"u}lent}, title = {Dose-escalated salvage radiotherapy for macroscopic local recurrence of prostate cancer in the prostate-specific membrane antigen positron emission tomography era}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {19}, issn = {2072-6694}, doi = {10.3390/cancers14194956}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290302}, year = {2022}, abstract = {Simple Summary Prostate cancer often relapses after initial radical prostatectomy, and salvage radiotherapy offers a second chance of cure for relapsed patients. Modern imaging techniques, especially prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT), enable radiation oncologists to target radiotherapy at the involved sites of disease. In a group of patients, PSMA PET/CT imaging can detect a macroscopic local recurrence with or without locoregional lymph node metastasis. In these cases, an escalation of the radiotherapy dose is often considered for controlling the visible tumor mass. As the evidence for dose-escalated salvage radiotherapy for macroscopic recurrent prostate cancer after PSMA PET/CT imaging is still limited, we address this topic in the current analysis. We found that the outcome of patients with dose-escalated salvage radiotherapy for macroscopic prostate cancer recurrence is encouragingly favorable, while the toxicity is very limited. Abstract Background: The purpose of this study was to access the oncological outcome of prostate-specific membrane antigen positron emission tomography (PSMA PET/CT)-guided salvage radiotherapy (SRT) for localized macroscopic prostate cancer recurrence. Methods: Between February 2010 and June 2021, 367 patients received SRT after radical prostatectomy. Out of the 367 screened patients, 111 patients were staged by PSMA PET/CT before SRT. A total of 59 out of these 111 (53.2\%) patients were treated for PSMA PET-positive macroscopic prostatic fossa recurrence. Dose-escalated SRT was applied with a simultaneous integrated boost at a median prescribed dose of 69.3 Gy (IQR 69.3-72.6 Gy). The oncological outcome was investigated using Kaplan-Meier and Cox regression analyses. The genitourinary (GU)/gastrointestinal (GI) toxicity evaluation utilized Common Toxicity Criteria for Adverse Events (version 5.0). Results: The median follow-up was 38.2 months. The three-year biochemical progression-free survival rate was 89.1\% (95\% CI: 81.1-97.8\%) and the three-year metastasis-free survival rate reached 96.2\% (95\% CI: 91.2-100.0\%). The cumulative three-year late grade 3 GU toxicity rate was 3.4\%. No late grade 3 GI toxicity occurred. Conclusions: Dose-escalated PSMA PET/CT-guided salvage radiotherapy for macroscopic prostatic fossa recurrence resulted in favorable survival and toxicity rates.}, language = {en} } @article{TamihardjaZehnerHartrampfetal.2022, author = {Tamihardja, J{\"o}rg and Zehner, Leonie and Hartrampf, Philipp and Lisowski, Dominik and Kneitz, Susanne and Cirsi, Sinan and Razinskas, Gary and Flentje, Michael and Polat, B{\"u}lent}, title = {Salvage nodal radiotherapy as metastasis-directed therapy for oligorecurrent prostate cancer detected by positron emission tomography shows favorable outcome in long-term follow-up}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {15}, issn = {2072-6694}, doi = {10.3390/cancers14153766}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286064}, year = {2022}, abstract = {Simple Summary Patients, who suffer from oligorecurrent prostate cancer with limited nodal involvement, may be offered positron emission tomography (PET)-directed salvage nodal radiotherapy to delay disease progression. This current analysis aimed to access salvage radiotherapy for nodal oligorecurrent prostate cancer with simultaneous integrated boost to PET-involved lymph nodes as metastasis-directed therapy. A long-term oncological outcome was favorable after salvage nodal radiotherapy and severe toxicity rates were low. Androgen deprivation therapy plays a major role in recurrent prostate cancer management and demonstrates a positive influence on the rate of biochemical progression in patients receiving salvage nodal radiotherapy. The present long-term analysis may help clinicians identify patients who would benefit from salvage nodal radiotherapy and androgen deprivation therapy, as a multimodal treatment strategy for oligorecurrent prostate cancer. Abstract Background: The study aimed to access the long-term outcome of salvage nodal radiotherapy (SNRT) in oligorecurrent prostate cancer. Methods: A total of 95 consecutive patients received SNRT for pelvic and/or extrapelvic nodal recurrence after prostate-specific membrane antigen (PSMA) or choline PET from 2010 to 2021. SNRT was applied as external beam radiotherapy with simultaneous integrated boost up to a median total dose of 62.9 Gy (EQD2\(_{1.5Gy}\)) to the recurrent lymph node metastases. The outcome was analyzed by cumulative incidence functions with death as the competing risk. Fine-Gray regression analyses were performed to estimate the relative hazards of the outcome parameters. Genitourinary (GU)/gastrointestinal (GI) toxicity evaluation utilized Common Toxicity Criteria for Adverse Events (v5.0). The results are as follows: the median follow-up was 47.1 months. The five-year biochemical progression rate (95\% CI) was 50.1\% (35.7-62.9\%). Concomitant androgen deprivation therapy (ADT) was adminstered in 60.0\% of the patients. The five-year biochemical progression rate was 75.0\% (42.0-90.9\%) without ADT versus 35.3\% (19.6-51.4\%) with ADT (p = 0.003). The cumulative five-year late grade 3 GU toxicity rate was 2.1\%. No late grade 3 GI toxicity occured. Conclusions: Metastasis-directed therapy through SNRT for PET-staged oligorecurrent prostate cancer demonstrated a favorable long-term oncologic outcome. Omittance of ADT led to an increased biochemical progression.}, language = {en} } @article{KosmalaSerflingDreheretal.2022, author = {Kosmala, Aleksander and Serfling, Sebastian E. and Dreher, Niklas and Lindner, Thomas and Schirbel, Andreas and Lapa, Constantin and Higuchi, Takahiro and Buck, Andreas K. and Weich, Alexander and Werner, Rudolf A.}, title = {Associations between normal organs and tumor burden in patients imaged with fibroblast activation protein inhibitor-directed positron emission tomography}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {11}, issn = {2072-6694}, doi = {10.3390/cancers14112609}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275154}, year = {2022}, abstract = {(1) Background: We aimed to quantitatively investigate [\(^{68}\)Ga]Ga-FAPI-04 uptake in normal organs and to assess a relationship with the extent of FAPI-avid tumor burden. (2) Methods: In this single-center retrospective analysis, thirty-four patients with solid cancers underwent a total of 40 [\(^{68}\)Ga]Ga-FAPI-04 PET/CT scans. Mean standardized uptake values (SUV\(_{mean}\)) for normal organs were established by placing volumes of interest (VOIs) in the heart, liver, spleen, pancreas, kidneys, and bone marrow. Total tumor burden was determined by manual segmentation of tumor lesions with increased uptake. For tumor burden, quantitative assessment included maximum SUV (SUV\(_{max}\)), tumor volume (TV), and fractional tumor activity (FTA = TV × SUV\(_{mean}\)). Associations between uptake in normal organs and tumor burden were investigated by applying Spearman's rank correlation coefficient. (3) Results: Median SUV\(_{mean}\) values were 2.15 in the pancreas (range, 1.05-9.91), 1.42 in the right (range, 0.57-3.06) and 1.41 in the left kidney (range, 0.73-2.97), 1.2 in the heart (range, 0.46-2.59), 0.86 in the spleen (range, 0.55-1.58), 0.65 in the liver (range, 0.31-2.11), and 0.57 in the bone marrow (range, 0.26-0.94). We observed a trend towards significance for uptake in the myocardium and tumor-derived SUV\(_{max}\) (ρ = 0.29, p = 0.07) and TV (ρ = -0.30, p = 0.06). No significant correlation was achieved for any of the other organs: SUV\(_{max}\) (ρ ≤ 0.1, p ≥ 0.42), TV (ρ ≤ 0.11, p ≥ 0.43), and FTA (ρ ≤ 0.14, p ≥ 0.38). In a sub-analysis exclusively investigating patients with high tumor burden, significant correlations of myocardial uptake with tumor SUV\(_{max}\) (ρ = 0.44; p = 0.03) and tumor-derived FTA with liver uptake (ρ = 0.47; p = 0.02) were recorded. (4) Conclusions: In this proof-of-concept study, quantification of [\(^{68}\)Ga]Ga-FAPI-04 PET showed no significant correlation between normal organs and tumor burden, except for a trend in the myocardium. Those preliminary findings may trigger future studies to determine possible implications for treatment with radioactive FAP-targeted drugs, as higher tumor load or uptake may not lead to decreased doses in the majority of normal organs.}, language = {en} } @article{TolstikAliGuoetal.2022, author = {Tolstik, Elen and Ali, Nairveen and Guo, Shuxia and Ebersbach, Paul and M{\"o}llmann, Dorothe and Arias-Loza, Paula and Dierks, Johann and Schuler, Irina and Freier, Erik and Debus, J{\"o}rg and Baba, Hideo A. and Nordbeck, Peter and Bocklitz, Thomas and Lorenz, Kristina}, title = {CARS imaging advances early diagnosis of cardiac manifestation of Fabry disease}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {10}, issn = {1422-0067}, doi = {10.3390/ijms23105345}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284427}, year = {2022}, abstract = {Vibrational spectroscopy can detect characteristic biomolecular signatures and thus has the potential to support diagnostics. Fabry disease (FD) is a lipid disorder disease that leads to accumulations of globotriaosylceramide in different organs, including the heart, which is particularly critical for the patient's prognosis. Effective treatment options are available if initiated at early disease stages, but many patients are late- or under-diagnosed. Since Coherent anti-Stokes Raman (CARS) imaging has a high sensitivity for lipid/protein shifts, we applied CARS as a diagnostic tool to assess cardiac FD manifestation in an FD mouse model. CARS measurements combined with multivariate data analysis, including image preprocessing followed by image clustering and data-driven modeling, allowed for differentiation between FD and control groups. Indeed, CARS identified shifts of lipid/protein content between the two groups in cardiac tissue visually and by subsequent automated bioinformatic discrimination with a mean sensitivity of 90-96\%. Of note, this genotype differentiation was successful at a very early time point during disease development when only kidneys are visibly affected by globotriaosylceramide depositions. Altogether, the sensitivity of CARS combined with multivariate analysis allows reliable diagnostic support of early FD organ manifestation and may thus improve diagnosis, prognosis, and possibly therapeutic monitoring of FD.}, language = {en} } @article{HartrampfKrebsPeteretal.2022, author = {Hartrampf, Philipp E. and Krebs, Markus and Peter, Lea and Heinrich, Marieke and Ruffing, Julia and Kalogirou, Charis and Weinke, Maximilian and Brumberg, Joachim and K{\"u}bler, Hubert and Buck, Andreas K. and Werner, Rudolf A. and Seitz, Anna Katharina}, title = {Reduced segmentation of lesions is comparable to whole-body segmentation for response assessment by PSMA PET/CT: initial experience with the keyhole approach}, series = {Biology}, volume = {11}, journal = {Biology}, number = {5}, issn = {2079-7737}, doi = {10.3390/biology11050660}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-271191}, year = {2022}, abstract = {Simple Summary The calculation of PSMA-positive tumor volume (PSMA-TV) of the whole body from PSMA PET scans for response evaluation remains a time-consuming procedure. We hypothesized that it may be possible to quantify changes in PSMA-TV by considering only a limited number of representative tumor lesions. Changes in the whole-body PSMA-TV of 65 patients were comparable to the changes in PSMA-TV after including only the ten largest lesions. Moreover, changes in PSMA-TV correlated well with changes in PSA levels, as did the changes in PSMA-TV with the reduced number of lesions. We conclude that a response assessment using PSMA-TV with a reduced number of lesions is feasible and could lead to a simplified process for evaluating PSMA PET/CT. Abstract (1) Background: Prostate-specific membrane antigen (PSMA) positron emission tomography (PET)-derived parameters, such as the commonly used standardized uptake value (SUV) and PSMA-positive tumor volume (PSMA-TV), have been proposed for response assessment in metastatic prostate cancer (PCa) patients. However, the calculation of whole-body PSMA-TV remains a time-consuming procedure. We hypothesized that it may be possible to quantify changes in PSMA-TV by considering only a limited number of representative lesions. (2) Methods: Sixty-five patients classified into different disease stages were assessed by PSMA PET/CT for staging and restaging after therapy. Whole-body PSMA-TV and whole-body SUV\(_{max}\) were calculated. We then repeated this calculation only including the five or ten hottest or largest lesions. The corresponding serum levels of prostate-specific antigen (PSA) were also determined. The derived delta between baseline and follow-up values provided the following parameters: ΔSUV\(_{maxall}\), ΔSUV\(_{max10}\), ΔSUV\(_{max5}\), ΔPSMA-TV\(_{all}\), ΔPSMA-TV\(_{10}\), ΔPSMA-TV\(_{5}\), ΔPSA. Finally, we compared the findings from our whole-body segmentation with the results from our keyhole approach (focusing on a limited number of lesions) and correlated all values with the biochemical response (ΔPSA). (3) Results: Among patients with metastatic hormone-sensitive PCa (mHSPC), none showed a relevant deviation for ΔSUV\(_{max10}\)/ΔSUV\(_{max5}\) or ΔPSMA-TV\(_{10}\)/ΔPSMA-TV\(_{5}\) compared to ΔSUV\(_{maxall}\) and ΔPSMA-TV\(_{all}\). For patients treated with taxanes, up to 6/21 (28.6\%) showed clinically relevant deviations between ΔSUV\(_{maxall}\) and ΔSUV\(_{max10}\) or ΔSUV\(_{max5}\), but only up to 2/21 (9.5\%) patients showed clinically relevant deviations between ΔPSMA-TV\(_{all}\) and ΔPSMA-TV\(_{10}\) or ΔPSMA-TV\(_{5}\). For patients treated with radioligand therapy (RLT), up to 5/28 (17.9\%) showed clinically relevant deviations between ΔSUV\(_{maxall}\) and ΔSUV\(_{max10}\) or ΔSUV\(_{max5}\), but only 1/28 (3.6\%) patients showed clinically relevant deviations between ΔPSMA-TV\(_{all}\) and ΔPSMA-TV\(_{10}\) or ΔPSMA-TV\(_{5}\). The highest correlations with ΔPSA were found for ΔPSMA-TV\(_{all}\) (r ≥ 0.59, p ≤ 0.01), followed by ΔPSMA-TV\(_{10}\) (r ≥ 0.57, p ≤ 0.01) and ΔPSMA-TV\(_{5}\) (r ≥ 0.53, p ≤ 0.02) in all cohorts. ΔPSA only correlated with ΔSUV\(_{maxall}\) (r = 0.60, p = 0.02) and with ΔSUV\(_{max10}\) (r = 0.53, p = 0.03) in the mHSPC cohort, as well as with ΔSUV\(_{maxall}\) (r = 0.51, p = 0.01) in the RLT cohort. (4) Conclusion: Response assessment using PSMA-TV with a reduced number of lesions is feasible, and may allow for a simplified evaluation process for PSMA PET/CT.}, language = {en} } @article{SchadtIsraelBeezetal.2023, author = {Schadt, Fabian and Israel, Ina and Beez, Alexandra and Alushi, Kastriot and Weiland, Judith and Ernestus, Ralf-Ingo and Westermaier, Thomas and Samnick, Samuel and Lilla, Nadine}, title = {Analysis of cerebral glucose metabolism following experimental subarachnoid hemorrhage over 7 days}, series = {Scientific Reports}, volume = {13}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-022-26183-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300725}, year = {2023}, abstract = {Little is known about changes in brain metabolism following SAH, possibly leading towards secondary brain damage. Despite sustained progress in the last decade, analysis of in vivo acquired data still remains challenging. The present interdisciplinary study uses a semi-automated data analysis tool analyzing imaging data independently from the administrated radiotracer. The uptake of 2-[18F]Fluoro-2-deoxy-glucose ([\(^{18}\)F]FDG) was evaluated in different brain regions in 14 male Sprague-Dawley rats, randomized into two groups: (1) SAH induced by the endovascular filament model and (2) sham operated controls. Serial [\(^{18}\)F]FDG-PET measurements were carried out. Quantitative image analysis was performed by uptake ratio using a self-developed MRI-template based data analysis tool. SAH animals showed significantly higher [\(^{18}\)F]FDG accumulation in gray matter, neocortex and olfactory system as compared to animals of the sham group, while white matter and basal forebrain region showed significant reduced tracer accumulation in SAH animals. All significant metabolic changes were visualized from 3 h, over 24 h (day 1), day 4 and day 7 following SAH/sham operation. This [\(^{18}\)F]FDG-PET study provides important insights into glucose metabolism alterations following SAH—for the first time in different brain regions and up to day 7 during course of disease.}, language = {en} } @phdthesis{Heider2023, author = {Heider, Melanie}, title = {Detektionsrate der \(^{68}\)Ga-PSMA-PET/CT bei Patienten mit Rezidiv eines Prostatakarzinoms und Androgendeprivationstherapie}, doi = {10.25972/OPUS-30612}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-306123}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Die Detektion des Prostataspezifischen Membranantigens (PSMA) mittels kombinierter Positronenemissions- und Computertomographie (PET/CT) ist ein etabliertes diagnostisches Verfahren bei Patienten mit Prostatakarzinom. Hierbei ist bislang unklar, ob und wie eine bereits eingeleitete Androgendeprivationstherapie (ADT) die diagnostische Genauigkeit der PSMA-PET/CT beeinflusst. Ziel dieser Arbeit war es, die Detektionsrate der PSMA-PET/CT mit 68Ga-PSMA I\&T unter ADT in Abh{\"a}ngigkeit des PSA-Wertes zu evaluieren und mit einer Kontrollgruppe ohne ADT zu vergleichen. In dieser retrospektiven Studie wurden Daten von Patienten mit biochemischem Rezidiv nach radikaler Prostatektomie analysiert, welche zwischen 2014 und 2018 eine PSMA-PET/CT am Universit{\"a}tsklinikum W{\"u}rzburg erhalten haben. Mittels Propensity Score Matching wurde f{\"u}r die Patienten mit ADT innerhalb der letzten 6 Monate vor Durchf{\"u}hrung der PSMA-PET/CT eine Kontrollgruppe ohne ADT erstellt. Die Patienten mit ADT (n=62) wiesen eine signifikant h{\"o}here Detektionsrate auf als die Patienten ohne ADT (n=62). Die Traceranreicherung unterschied sich nicht signifikant in beiden Gruppen. Dagegen wiesen die Patienten mit ADT jedoch eine signifikant h{\"o}here Tumorlast auf und hatten h{\"a}ufiger Knochen- und Organmetastasen, sodass als Ursache f{\"u}r die h{\"o}here Detektionsrate der PSMA-PET/CT bei Patienten mit ADT ein fortgeschritteneres Tumorstadium angenommen wurde. Die Detektionsrate war bei den Patienten mit ADT auch bei niedrigen PSA-Werten hoch. Es scheint daher nicht erforderlich zu sein, eine bestehende ADT vor Durchf{\"u}hrung der PSMA-PET/CT im biochemischen Rezidiv abzusetzen und damit das Risiko einer Krankheitsprogression einzugehen. Die Korrelation des PSA-Wertes mit der Tumorlast in der PSMA-PET/CT war bei Patienten mit ADT geringer ausgepr{\"a}gt als bei Patienten ohne ADT. Patienten unter ADT k{\"o}nnten daher von einer regelm{\"a}ßigen Durchf{\"u}hrung der PSMA-PET/CT zur {\"U}berwachung der Krankheitsprogression profitieren. Hier bleibt allerdings eine Kosten-Nutzen-Analyse abzuwarten, da dies deutlich aufwendiger und teurer ist als die Bestimmung des PSA-Wertes.}, subject = {Positronen-Emissions-Tomografie}, language = {de} } @article{MatsusakaWernerAriasLozaetal.2022, author = {Matsusaka, Yohji and Werner, Rudolf A. and Arias-Loza, Paula and Nose, Naoko and Sasaki, Takanori and Chen, Xinyu and Lapa, Constantin and Higuchi, Takahiro}, title = {Performance Evaluation of a Preclinical SPECT Scanner with a Collimator Designed for Medium-Sized Animals}, series = {Molecular Imaging}, volume = {2022}, journal = {Molecular Imaging}, doi = {10.1155/2022/9810097}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300713}, year = {2022}, abstract = {Background. Equipped with two stationary detectors, a large bore collimator for medium-sized animals has been recently introduced for dedicated preclinical single-photon emission computed tomography (SPECT) imaging. We aimed to evaluate the basic performance of the system using phantoms and healthy rabbits. Methods. A general-purpose medium-sized animal (GP-MSA) collimator with 135 mm bore diameter and thirty-three holes of 2.5 mm diameter was installed on an ultrahigh-resolution scanner equipped with two large stationary detectors (U-SPECT5-E/CT). The sensitivity and uniformity were investigated using a point source and a cylinder phantom containing 99mTc-pertechnetate, respectively. Uniformity (in \%) was derived using volumes of interest (VOIs) on images of the cylinder phantom and calculated as , with lower values of \% indicating superior performance. The spatial resolution and contrast-to-noise ratios (CNRs) were evaluated with images of a hot-rod Derenzo phantom using different activity concentrations. Feasibility of in vivo SPECT imaging was finally confirmed by rabbit imaging with the most commonly used clinical myocardial perfusion SPECT agent [99mTc]Tc-sestamibi (dynamic acquisition with a scan time of 5 min). Results. In the performance evaluation, a sensitivity of 790 cps/MBq, a spatial resolution with the hot-rod phantom of 2.5 mm, and a uniformity of 39.2\% were achieved. The CNRs of the rod size 2.5 mm were 1.37, 1.24, 1.20, and 0.85 for activity concentration of 29.2, 1.0, 0.5, and 0.1 MBq/mL, respectively. Dynamic SPECT imaging in rabbits allowed to visualize most of the thorax and to generate time-activity curves of the left myocardial wall and ventricular cavity. Conclusion. Preclinical U-SPECT5-E/CT equipped with a large bore collimator demonstrated adequate sensitivity and resolution for in vivo rabbit imaging. Along with its unique features of SPECT molecular functional imaging is a superior collimator technology that is applicable to medium-sized animal models and thus may promote translational research for diagnostic purposes and development of novel therapeutics.}, language = {en} } @article{MatsusakaChenAriasLozaetal.2022, author = {Matsusaka, Yohji and Chen, Xinyu and Arias-Loza, Paula and Werner, Rudolf A. and Nose, Naoko and Sasaki, Takanori and Rowe, Steven P. and Pomper, Martin G. and Lapa, Constantin and Higuchi, Takahiro}, title = {In Vivo Functional Assessment of Sodium-Glucose Cotransporters (SGLTs) Using [\(^{18}\)F]Me4FDG PET in Rats}, series = {Molecular Imaging}, volume = {2022}, journal = {Molecular Imaging}, doi = {10.1155/2022/4635171}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300708}, year = {2022}, abstract = {Background. Mediating glucose absorption in the small intestine and renal clearance, sodium glucose cotransporters (SGLTs) have emerged as an attractive therapeutic target in diabetic patients. A substantial fraction of patients, however, only achieve inadequate glycemic control. Thus, we aimed to assess the potential of the SGLT-targeting PET radiotracer alpha-methyl-4-deoxy-4-[\(^{18}\)F]fluoro-D-glucopyranoside ([\(^{18}\)F]Me4FDG) as a noninvasive intestinal and renal biomarker of SGLT-mediated glucose transport. Methods. We investigated healthy rats using a dedicated small animal PET system. Dynamic imaging was conducted after administration of the reference radiotracer 2-deoxy-2-[\(^{18}\)F]fluoro-D-glucose ([\(^{18}\)F]FDG), or the SGLT-targeting agent, [\(^{18}\)F]Me4FDG either directly into the digestive tract (for assessing intestinal absorption) or via the tail vein (for evaluating kidney excretion). To confirm the specificity of [18F]Me4FDG and responsiveness to treatment, a subset of animals was also pretreated with the SGLT inhibitor phlorizin. In this regard, an intraintestinal route of administration was used to assess tracer absorption in the digestive tract, while for renal assessment, phlorizin was injected intravenously (IV). Results. Serving as reference, intestinal administration of [\(^{18}\)F]FDG led to slow absorption with retention of \% of administered radioactivity at 15 min. [\(^{18}\)F]Me4FDG, however, was rapidly absorbed into the blood and cleared from the intestine within 15 min, leading to markedly lower tracer retention of \% (). Intraintestinal phlorizin led to marked increase of [\(^{18}\)F]Me4FDG uptake (15 min, \%; vs. untreated controls), supporting the notion that this PET agent can measure adequate SGLT inhibition in the digestive tract. In the kidneys, radiotracer was also sensitive to SGLT inhibition. After IV injection, [\(^{18}\)F]Me4FDG reabsorption in the renal cortex was significantly suppressed by phlorizin when compared to untreated animals (\%ID/g at 60 min, vs. untreated controls, ; ). Conclusion. As a noninvasive read-out of the concurrent SGLT expression in both the digestive tract and the renal cortex, [\(^{18}\)F]Me4FDG PET may serve as a surrogate marker for treatment response to SGLT inhibition. As such, [\(^{18}\)F]Me4FDG may enable improvement in glycemic control in diabetes by PET-based monitoring strategies.}, language = {en} } @article{GramGenslerAlbertovaetal.2022, author = {Gram, Maximilian and Gensler, Daniel and Albertova, Petra and Gutjahr, Fabian Tobias and Lau, Kolja and Arias-Loza, Paula-Anahi and Jakob, Peter Michael and Nordbeck, Peter}, title = {Quantification correction for free-breathing myocardial T1ρ mapping in mice using a recursively derived description of a T\(_{1p}\)\(^{*}\) relaxation pathway}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {24}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {1}, doi = {10.1186/s12968-022-00864-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300491}, year = {2022}, abstract = {Background Fast and accurate T1ρ mapping in myocardium is still a major challenge, particularly in small animal models. The complex sequence design owing to electrocardiogram and respiratory gating leads to quantification errors in in vivo experiments, due to variations of the T\(_{1p}\) relaxation pathway. In this study, we present an improved quantification method for T\(_{1p}\) using a newly derived formalism of a T\(_{1p}\)\(^{*}\) relaxation pathway. Methods The new signal equation was derived by solving a recursion problem for spin-lock prepared fast gradient echo readouts. Based on Bloch simulations, we compared quantification errors using the common monoexponential model and our corrected model. The method was validated in phantom experiments and tested in vivo for myocardial T\(_{1p}\) mapping in mice. Here, the impact of the breath dependent spin recovery time T\(_{rec}\) on the quantification results was examined in detail. Results Simulations indicate that a correction is necessary, since systematically underestimated values are measured under in vivo conditions. In the phantom study, the mean quantification error could be reduced from - 7.4\% to - 0.97\%. In vivo, a correlation of uncorrected T\(_{1p}\) with the respiratory cycle was observed. Using the newly derived correction method, this correlation was significantly reduced from r = 0.708 (p < 0.001) to r = 0.204 and the standard deviation of left ventricular T\(_{1p}\) values in different animals was reduced by at least 39\%. Conclusion The suggested quantification formalism enables fast and precise myocardial T\(_{1p}\) quantification for small animals during free breathing and can improve the comparability of study results. Our new technique offers a reasonable tool for assessing myocardial diseases, since pathologies that cause a change in heart or breathing rates do not lead to systematic misinterpretations. Besides, the derived signal equation can be used for sequence optimization or for subsequent correction of prior study results.}, language = {en} } @article{ChenWernerKoshinoetal.2022, author = {Chen, Xinyu and Werner, Rudolf A. and Koshino, Kazuhiro and Nose, Naoko and M{\"u}hlig, Saskia and Rowe, Steven P. and Pomper, Martin G. and Lapa, Constantin and Decker, Michael and Higuchi, Takahiro}, title = {Molecular Imaging-Derived Biomarker of Cardiac Nerve Integrity - Introducing High NET Affinity PET Probe \(^{18}\)F-AF78}, series = {Theranostics}, volume = {12}, journal = {Theranostics}, number = {9}, doi = {10.7150/thno.63205}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300685}, pages = {4446 -- 4458}, year = {2022}, abstract = {Background: Radiolabeled agents that are substrates for the norepinephrine transporter (NET) can be used to quantify cardiac sympathetic nervous conditions and have been demonstrated to identify high-risk congestive heart failure (HF) patients prone to arrhythmic events. We aimed to fully characterize the kinetic profile of the novel \(^{18}\)F-labeled NET probe AF78 for PET imaging of the cardiac sympathetic nervous system (SNS) among various species. Methods: \(^{18}\)F-AF78 was compared to norepinephrine (NE) and established SNS radiotracers by employing in vitro cell assays, followed by an in vivo PET imaging approach with healthy rats, rabbits and nonhuman primates (NHPs). Additionally, chase protocols were performed in NHPs with NET inhibitor desipramine (DMI) and the NE releasing stimulator tyramine (TYR) to investigate retention kinetics in cardiac SNS. Results: Relative to other SNS radiotracers, 18F-AF78 showed higher transport affinity via NET in a cell-based competitive uptake assay (IC\(^{50}\) 0.42 ± 0.14 µM), almost identical to that of NE (IC\(^{50}\), 0.50 ± 0.16 µM, n.s.). In rabbits and NHPs, initial cardiac uptake was significantly reduced by NET inhibition. Furthermore, cardiac tracer retention was not affected by a DMI chase protocol but was markedly reduced by intermittent TYR chase, thereby suggesting that \(^{18}\)F-AF78 is stored and can be released via the synaptic vesicular turnover process. Computational modeling hypothesized the formation of a T-shaped π-π stacking at the binding site, suggesting a rationale for the high affinity of \(^{18}\)F-AF78. Conclusion: \(^{18}\)F-AF78 demonstrated high in vitro NET affinity and advantageous in vivo radiotracer kinetics across various species, indicating that \(^{18}\)F-AF78 is an SNS imaging agent with strong potential to guide specific interventions in cardiovascular medicine.}, language = {en} } @article{AsterRomanosWalitzaetal.2022, author = {Aster, Hans-Christoph and Romanos, Marcel and Walitza, Susanne and Gerlach, Manfred and M{\"u}hlberger, Andreas and Rizzo, Albert and Andreatta, Marta and Hasenauer, Natalie and Hartrampf, Philipp E. and Nerlich, Kai and Reiners, Christoph and Lorenz, Reinhard and Buck, Andreas K. and Deserno, Lorenz}, title = {Responsivity of the striatal dopamine system to methylphenidate — A within-subject I-123-β-CIT-SPECT study in male children and adolescents with attention-deficit/hyperactivity disorder}, series = {Frontiers in Psychiatry}, volume = {13}, journal = {Frontiers in Psychiatry}, issn = {1664-0640}, doi = {10.3389/fpsyt.2022.804730}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270862}, year = {2022}, abstract = {Background: Methylphenidate (MPH) is the first-line pharmacological treatment of attention-deficit/hyperactivity disorder (ADHD). MPH binds to the dopamine (DA) transporter (DAT), which has high density in the striatum. Assessments of the striatal dopamine transporter by single positron emission computed tomography (SPECT) in childhood and adolescent patients are rare but can provide insight on how the effects of MPH affect DAT availability. The aim of our within-subject study was to investigate the effect of MPH on DAT availability and how responsivity to MPH in DAT availability is linked to clinical symptoms and cognitive functioning. Methods Thirteen adolescent male patients (9-16 years) with a diagnosis of ADHD according to the DSM-IV and long-term stimulant medication (for at least 6 months) with MPH were assessed twice within 7 days using SPECT after application of I-123-β-CIT to examine DAT binding potential (DAT BP). SPECT measures took place in an on- and off-MPH status balanced for order across participants. A virtual reality continuous performance test was performed at each time point. Further clinical symptoms were assessed for baseline off-MPH. Results On-MPH status was associated with a highly significant change (-29.9\%) of striatal DAT BP as compared to off-MPH (t = -4.12, p = 0.002). A more pronounced change in striatal DAT BP was associated with higher off-MPH attentional and externalizing symptom ratings (Pearson r = 0.68, p = 0.01). Striatal DAT BP off-MPH, but not on-MPH, was associated with higher symptom ratings (Pearson r = 0.56, p = 0.04). Conclusion Our findings corroborate previous reports from mainly adult samples that MPH changes striatal DAT BP availability and suggest higher off-MPH DAT BP, likely reflecting low baseline DA levels, as a marker of symptom severity.}, language = {en} } @phdthesis{Page2022, author = {Page, Lukas}, title = {Entwicklung und pr{\"a}klinische Evaluation immunologischer und nuklearmedizinischer diagnostischer Tests f{\"u}r Schimmelpilz-assoziierte Hypersensitivit{\"a}t und invasive Mykosen}, doi = {10.25972/OPUS-25245}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252459}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Schimmelpilze k{\"o}nnen in Abh{\"a}ngigkeit des Immunstatus und der Vorerkrankungen betroffener Patienten unterschiedliche Krankheitsbilder wie Hypersensitivit{\"a}ts-erkrankungen oder lebensbedrohliche invasive Infektionen hervorrufen. Da die Diagnosestellung dieser Erkrankungen mitunter komplex und insensitiv ist, sollten im Rahmen dieser Arbeit unterschiedliche Ans{\"a}tze neuer diagnostischer Assays untersucht werden. In den letzten Jahren wurden Assays entwickelt, die auf Basis durchflusszytometrisch quantifizierter Pilz-spezifischer T-Zellen aus peripherem Blut einen supportiven Biomarker zur Diagnostik invasiver Mykosen liefern k{\"o}nnten. Da die hierf{\"u}r isolierten T-Zellen anf{\"a}llig gegen{\"u}ber pr{\"a}analytischer Lagerzeiten und immunsuppressiver Medikation sind, wurden hier Protokolloptimierungen vorgenommen, um anhand eines Vollblut-basierten Assays mit zus{\"a}tzlicher CD49d-Kostimulation diesen Limitationen entgegen zu wirken. In einer Studie an gesunden Probanden konnte dabei gezeigt werden, dass die Kombination der Durchflusszytometrie mit ausgew{\"a}hlten Zytokin-Messungen (IL-5, IL-10 und IL-17) zu einer verbesserten Erkennung vermehrt Schimmelpilz-exponierter Personen beitragen k{\"o}nnte. Neben Infektionen k{\"o}nnten dabei im umwelt- und arbeitsmedizinischen Kontext Polarisationen der T-Zell-Populationen detektiert werden, welche mit Sensibilisierungen und Hypersensitivit{\"a}t assoziiert werden. Zus{\"a}tzlich wurde ein in vitro Transwell® Alveolarmodell zur Simulation pulmonaler Pilzinfektionen f{\"u}r Erreger der Ordnung Mucorales adaptiert, durch Reproduktion wichtiger Merkmale der Pathogenese von Mucormykosen validiert, und f{\"u}r Untersuchungen der Immunpathologie und Erreger-Invasion verwendet. Das Modell wurde anschließend zur in vitro Evaluation von radioaktiv markiertem Amphotericin B mit 99mTc oder 68Ga als nuklearmedizinischen Tracer verwendet. Die untersuchten Schimmelpilze zeigten dabei eine zeit- und dosis-abh{\"a}ngige Aufnahme der Tracer, w{\"a}hrend bakteriell infizierte Proben nicht detektiert wurden. Die erhobenen Daten dokumentieren ein vielversprechendes Potenzial von Amphotericin B-basierten Tracer, das in zuk{\"u}nftigen in vivo Studien weiter evaluiert werden sollte.}, subject = {Schimmelpilze}, language = {de} } @article{AngheloiuHaenscheidWenetal.2012, author = {Angheloiu, George O. and H{\"a}nscheid, Heribert and Wen, Xiaoyan and Capponi, Vincent and Anderson, William D. and Kellum, John A.}, title = {Experimental first-pass method for testing and comparing sorbent polymers used in the clearance of iodine contrast materials}, series = {Blood Purification}, volume = {34}, journal = {Blood Purification}, number = {1}, issn = {0253-5068}, doi = {10.1159/000339816}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199118}, pages = {34-39}, year = {2012}, abstract = {Background: Sorbents have been shown to adsorb iodinated radiocontrast media. Objective: In this study we describe a simple method to compare various sorbents in terms of capacity to adsorb radiocontrast media. Methods: Iodixanol solution was injected into columns filled with three types of sorbent at filtration velocities of increasing magnitude. Two variables of interest - contrast removal rate and matched iodine retention (MIR) - were calculated to measure the adsorption efficiency and the mass of contrast iodine adsorbed versus sorbent used, respectively. Results: The highest contrast removal and MIR for Porapak Q, CST 401 and Amberlite XAD4 were 41, 38 and 16\% (p = 0.22 and 0.0005 for comparisons between Porapak Q-CST 401 and CST 401-Amberlite XAD4) and 0.060, 0.055 and 0.024, respectively (p = 0.18 and 0.0008). Extrapolation to a clinical scenario may suggest that removal of 8 ml iodixanol could be achieved by masses of sorbents of 43, 47 and 107 g, respectively. Conclusion: In this study we set a benchmark for comparing the radiocontrast-adsorbing efficiency of polymer sorbents during first-pass experiments, using a readily available methodology.}, language = {en} } @article{MihatschBeissertPomperetal.2022, author = {Mihatsch, Patrick W. and Beissert, Matthias and Pomper, Martin G. and Bley, Thorsten A. and Seitz, Anna K. and K{\"u}bler, Hubert and Buck, Andreas K. and Rowe, Steven P. and Serfling, Sebastian E. and Hartrampf, Philipp E. and Werner, Rudolf A.}, title = {Changing threshold-based segmentation has no relevant impact on semi-quantification in the context of structured reporting for PSMA-PET/CT}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {2}, issn = {2072-6694}, doi = {10.3390/cancers14020270}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254782}, year = {2022}, abstract = {Prostate-specific membrane antigen (PSMA)-directed positron emission tomography/computed tomography (PET/CT) is increasingly utilized for staging of men with prostate cancer (PC). To increase interpretive certainty, the standardized PSMA reporting and data system (RADS) has been proposed. Using PSMA-RADS, we characterized lesions in 18 patients imaged with \(^{18}\)F-PSMA-1007 PET/CT for primary staging and determined the stability of semi-quantitative parameters. Six hundred twenty-three lesions were categorized according to PSMA-RADS and manually segmented. In this context, PSMA-RADS-3A (soft-tissue) or -3B (bone) lesions are defined as being indeterminate for the presence of PC. For PMSA-RADS-4 and -5 lesions; however, PC is highly likely or almost certainly present [with further distinction based on absence (PSMA-RADS-4) or presence (PSMA-RADS-5) of correlative findings on CT]. Standardized uptake values (SUV\(_{max}\), SUV\(_{peak}\), SUV\(_{mean}\)) were recorded, and volumetric parameters [PSMA-derived tumor volume (PSMA-TV); total lesion PSMA (TL-PSMA)] were determined using different maximum intensity thresholds (MIT) (40 vs. 45 vs. 50\%). SUV\(_{max}\) was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories (p ≤ 0.0322). In particular, the clinically challenging PSMA-RADS-3A lesions showed significantly lower SUV\(_{max}\) and SUV\(_{peak}\) compared to the entire PSMA-RADS-4 or -5 cohort (p < 0.0001), while for PSMA-RADS-3B this only applies when compared to the entire PSMA-RADS-5 cohort (p < 0.0001), but not to the PSMA-RADS-4 cohort (SUV\(_{max}\), p = 0.07; SUV\(_{peak}\), p = 0.08). SUV\(_{mean}\) (p = 0.30) and TL-PSMA (p = 0.16) in PSMA-RADS-5 lesions were not influenced by changing the MIT, while PSMA-TV showed significant differences when comparing 40 vs. 50\% MIT (p = 0.0066), which was driven by lymph nodes (p = 0.0239), but not bone lesions (p = 0.15). SUV\(_{max}\) was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories in \(^{18}\)F-PSMA-1007 PET/CT. As such, the latter parameter may assist the interpreting molecular imaging specialist in assigning the correct PSMA-RADS score to sites of disease, thereby increasing diagnostic certainty. In addition, changes of the MIT in PSMA-RADS-5 lesions had no significant impact on SUV\(_{mean}\) and TL-PSMA in contrast to PSMA-TV.}, language = {en} } @phdthesis{Schadt2022, author = {Schadt, Fabian}, title = {Entwicklung und erste Validierung eines innovativen Analysen-Tools f{\"u}r pr{\"a}klinische Bewertungen von PET-Radiopharmazeutika zur \(in\) \(vivo\) Untersuchungen neurologischer Erkrankungen}, doi = {10.25972/OPUS-24749}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-247499}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Die pr{\"a}klinische Forschung stellt den ersten wichtigen Meilenstein in der Kl{\"a}rung und Untersuchung klinisch-relevanter Erkrankungen dar. Dar{\"u}ber hinaus unterst{\"u}tzt die pr{\"a}klinische Forschung erheblich die Entwicklung von Therapien. Die Kleintier-Positronenemissionstomographie (µ-PET) spielt dabei eine wichtige Rolle, da sie in der Lage ist, funktionelle, physiologische und biochemische Prozesse in vivo darzustellen und zu quantifizieren. Trotz diverser etablierter PET-Datenauswertungs-Programme bleibt die Analyse von in vivo akquirierten Bilddaten aufgrund der Vielzahl an medizinischen Fragestellungen, der Komplexit{\"a}t der Krankheitsbilder, sowie der Etablierung neuer Radiotracer weiterhin eine große Herausforderung in der Medizin. Ziel dieser Doktorarbeit ist es daher, ein geeignetes, brauchbares Auswertungstool f{\"u}r eine einfache und effiziente Analyse von akquirierten µ-PET-Daten zu entwickeln und zu etablieren, welches das Spektrum bereits vorhandener Programme erweitert. Das entwickelte nuklearmedizinische Datenverarbeitungs-Analyseprogramm (engl. nuclear medicine data processing analysis tool, NU_DPA) wurde in Matlab implementiert und anhand dreier pr{\"a}klinischer Versuchs- bzw. Testreihen erprobt und etabliert. Bei den Datenreihen handelt es sich um µ-PET-Datens{\"a}tze verschiedener Schlaganfall-Rattenhirnmodelle unter Verwendung folgender Radiotracer. Zum einen die im Gehirn homogen akkumulierende 2-[18F]Fluor-2-desoxy-glukose ([18F]FDG) zum anderen das spezifisch an P-Selektin anreichernde [68Ga]Fucoidan. Das NU_DPA umfasst die automatische Selektion des Zielvolumens (volume-of-interest, VOI) aus dem vollst{\"a}ndigen PET-Bild und die anschließende Ausrichtung des VOI mit Hilfe eines PET-Templates (gemittelter PET-Datensatz). Dieses PET Template wird aus den eigenen akquirierten PET-Daten erstellt. Durch das Einbinden eines geeigneten anatomischen MRT-Atlas' (anpassbar) k{\"o}nnen die ausgerichteten PET-Daten einzelnen, Atlas-spezifischen Teilregionen zugeordnet werden. Eine solche Subklassifikation des VOI erlaubt eine genauere Betrachtung und Auswertung der Radiotracer-Akkumulation. Des Weiteren bietet NU_DPA die M{\"o}glichkeit einer semiquantitativen Auswertung der PET-Bilddaten anhand von drei unterschiedlichen Parametern, der normalisierten Aktivit{\"a}t, dem Standardized Uptake Value und der Uptake Ratio. Durch die Matlab-integrierten Statistik-Algorithmen ist zus{\"a}tzlich eine M{\"o}glichkeit der statistischen Auswertung der zuvor berechneten Parameter gegeben. Das NU_DPA-Programm stellt somit ein semi-automatisiertes Datenauswertungs-Programm dar, das sowohl die Registrierung als auch die semiquantitative Auswertung von PET-Bilddaten innerhalb einer Versuchsreihe erm{\"o}glicht und bereits erfolgreich f{\"u}r die Radiotracer [18F]FDG und [68Ga]Fucoidan in Tiermodellen getestet wurde. Nach derzeitigem Kenntnisstand ist kein Datenauswertungs-Programm bekannt, das PET-Bilddaten unter Verwendung des hinzugef{\"u}gten Atlas' semi-automatisiert analysieren kann und potenziell f{\"u}r homogene und Target-spezifisch akkumulierende Radiotracer geeignet ist.}, subject = {PET}, language = {de} } @article{HaenscheidHartrampfSchirbeletal.2021, author = {H{\"a}nscheid, Heribert and Hartrampf, Philipp E. and Schirbel, Andreas and Buck, Andreas K. and Lapa, Constantin}, title = {Intraindividual comparison of [\(^{177}\)Lu]Lu-DOTA-EB-TATE and [\(^{177}\)Lu]Lu-DOTA-TOC}, series = {European Journal of Nuclear Medicine and Molecular Imaging}, volume = {48}, journal = {European Journal of Nuclear Medicine and Molecular Imaging}, number = {8}, issn = {1619-7089}, doi = {10.1007/s00259-020-05177-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265470}, pages = {2566-2572}, year = {2021}, abstract = {Purpose The radiolabelled somatostatin analogue [\(^{177}\)Lu]Lu-DOTA-EB-TATE binds to albumin via Evans blue, thereby increasing the residence time in the blood and potentially allowing more therapeutic agent to be absorbed into the target tissue during peptide receptor radionuclide therapy. It was tested in selected patients whether the substance is superior to [\(^{177}\)Lu]Lu-DOTA-TOC. Methods Activity kinetics in organs and tumours after [\(^{177}\)Lu]Lu-DOTA-EB-TATE and [\(^{177}\)Lu]Lu-DOTA-TOC were compared intraindividually in five patients with progressive somatostatin receptor-positive disease scheduled for radionuclide therapy. Resuluts In comparison to [\(^{177}\)Lu]Lu-DOTA-TOC, tumour doses per administered activity were higher for [\(^{177}\)Lu]Lu-DOTA-EB-TATE in 4 of 5 patients (median ratio: 1.7; range: 0.9 to 3.9), kidney doses (median ratio: 3.2; range: 1.6 to 9.8) as well as spleen doses (median ratio: 4.7; range 1.2 to 6.2) in all patients, and liver doses in 3 of 4 evaluable patients (median ratio: 4.0; range: 0.7 to 4.9). The tumour to critical organs absorbed dose ratios were higher after [\(^{177}\)Lu]Lu-DOTA-TOC in 4 of 5 patients. Conclusions Prior to a treatment with [\(^{177}\)Lu]Lu-DOTA-EB-TATE, it should be assessed individually whether the compound is superior to established substances.}, language = {en} } @article{SchumannEberleinLapaetal.2021, author = {Schumann, S. and Eberlein, U. and Lapa, C. and M{\"u}ller, J. and Serfling, S. and Lassmann, M. and Scherthan, H.}, title = {α-Particle-induced DNA damage tracks in peripheral blood mononuclear cells of [\(^{223}\)Ra]RaCl\(_{2}\)-treated prostate cancer patients}, series = {European Journal of Nuclear Medicine and Molecular Imaging}, volume = {48}, journal = {European Journal of Nuclear Medicine and Molecular Imaging}, number = {9}, issn = {1619-7089}, doi = {10.1007/s00259-020-05170-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265462}, pages = {2761-2770}, year = {2021}, abstract = {Purpose One therapy option for prostate cancer patients with bone metastases is the use of [\(^{223}\)Ra]RaCl\(_{2}\). The α-emitter \(^{223}\)Ra creates DNA damage tracks along α-particle trajectories (α-tracks) in exposed cells that can be revealed by immunofluorescent staining of γ-H2AX+53BP1 DNA double-strand break markers. We investigated the time- and absorbed dose-dependency of the number of α-tracks in peripheral blood mononuclear cells (PBMCs) of patients undergoing their first therapy with [\(^{223}\)Ra]RaCl\(_{2}\). Methods Multiple blood samples from nine prostate cancer patients were collected before and after administration of [\(^{223}\)Ra]RaCl\(_{2}\), up to 4 weeks after treatment. γ-H2AX- and 53BP1-positive α-tracks were microscopically quantified in isolated and immuno-stained PBMCs. Results The absorbed doses to the blood were less than 6 mGy up to 4 h after administration and maximally 16 mGy in total. Up to 4 h after administration, the α-track frequency was significantly increased relative to baseline and correlated with the absorbed dose to the blood in the dose range < 3 mGy. In most of the late samples (24 h - 4 weeks after administration), the α-track frequency remained elevated. Conclusion The γ-H2AX+53BP1 assay is a potent method for detection of α-particle-induced DNA damages during treatment with or after accidental incorporation of radionuclides even at low absorbed doses. It may serve as a biomarker discriminating α- from β-emitters based on damage geometry.}, language = {en} } @phdthesis{Messerschmidt2022, author = {Messerschmidt, Konstantin Felix}, title = {Einfluss der PSMA-Expression auf die Docetaxel-Sensitivit{\"a}t sowie systemischer Medikamente auf die Expression von PSMA, CXCR4 und SSTR2}, doi = {10.25972/OPUS-28336}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-283364}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {F{\"u}r das klinische Management des Prostatakarzinoms werden nuklearmedizinische Verfahren zunehmend relevant. Bildgebung und Therapie, welche gegen das Prostataspezifische Membranantigen (PSMA) gerichtet sind, werden bereits im klinischen Alltag angewendet. Weitere potenzielle Biomarker des Prostatakarzinoms, wie beispielsweise der CXC-Motiv-Chemokinrezeptor 4 (CXCR4) und der Somatostatinrezeptor Typ 2 (SSTR2), werden zudem als nuklearmedizinische Zielstrukturen diskutiert. Vorangegangene Arbeiten legten einen Zusammenhang zwischen dem Ausmaß der PSMA-Expression und der Sensitivit{\"a}t gegen{\"u}ber Docetaxel in Prostatakarzinomzellen nahe. Ein Ziel der vorliegenden Arbeit war, diesen Mechanismus genauer zu untersuchen. Dabei wurden die Aktivit{\"a}t onkogener Signalwege, die Proliferation und die CXCR4- sowie die Androgenrezeptor (AR)- Expression in Prostatakarzinomzelllinien mit unterschiedlicher PSMA-Expression durchflusszytometrisch quantifiziert. Im zweiten Projektteil sollte der Einfluss von Metformin und verschiedener, bereits in der Prostatakarzinomtherapie angewandter Medikamente (Docetaxel, Dexamethason, Abirateron und Enzalutamid), auf die Expression von PSMA, CXCR4 und SSTR2 untersucht werden. Die Quantifizierung der Expression erfolgte mittels Durchflusszytometrie. Ein kausaler Mechanismus f{\"u}r den Zusammenhang zwischen PSMA-Expression und Docetaxel-Sensitivit{\"a}t konnte in dieser Arbeit schließlich nicht hergestellt werden. Es zeigten sich jedoch vor allem Expressionsmodulationen von PSMA und CXCR4. Mittels Docetaxel konnte z.B. bei C4-2 Zellen eine Verdopplung der PSMA-Expression und eine Verdreifachung der CXCR4-Expression erreicht werden. Dar{\"u}ber hinaus zeigte die Behandlung mit Abirateron eine deutliche Heraufregulation der PSMA- Expression bei LNCaP und C4-2 Zellen, sowie eine Zunahme der CXCR4- Expression bei allen untersuchten Zelllinien. Sollte sich der Einfluss der medikament{\"o}sen Behandlung auf die Expression von PSMA und CXCR4 best{\"a}tigen, kann dies zuk{\"u}nftig zur verbesserten und individualisierten Diagnostik und Therapie von Prostatakarzinompatienten beitragen.}, subject = {Prostatakrebs}, language = {de} } @article{WernerHiguchiPomperetal.2021, author = {Werner, Rudolf A. and Higuchi, Takahiro and Pomper, Martin G. and Rowe, Steven P.}, title = {Theranostics in oncology — thriving, now more than ever}, series = {Diagnostics}, volume = {11}, journal = {Diagnostics}, number = {5}, issn = {2075-4418}, doi = {10.3390/diagnostics11050805}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236662}, year = {2021}, abstract = {Tracing its roots back to the 1940s, theranostics in nuclear oncology has proved successful mainly due to the beneficial effects of image-guided therapeutic concepts for patients afflicted with a variety of different cancers. The majority of these treatments are not only characterized by substantial prolongation of progression-free and overall survival, but are also generally safe, rendering theranostic agents as an attractive treatment option in various clinical scenarios in oncology. In this Special Issue Novel Theranostic Agents, nine original articles from around the globe provide further evidence on the use of the theranostic concept for neuroendocrine neoplasm (NEN), prostate cancer (PC), meningioma, and neuroblastoma. The investigated diagnostic and therapeutic radiotracers target not only established structures, such as somatostatin receptor, prostate-specific membrane antigen or norepinephrine transporter, but also recently emerging targets such as the C-X-C motif chemokine receptor 4. Moreover, the presented original articles also combine the concept of theranostics with in-depth read-out techniques such as radiomics or novel reconstruction algorithms on pretherapeutic scans, e.g., for outcome prediction. Even 80 years after its initial clinical introduction, theranostics in oncology continues to thrive, now more than ever.}, language = {en} } @article{KhatriChungWerneretal.2021, author = {Khatri, Wajahat and Chung, Hyun Woo and Werner, Rudolf A. and Leal, Jeffrey P. and Pienta, Kenneth J. and Lodge, Martin A. and Gorin, Michael A. and Pomper, Martin G. and Rowe, Steven P.}, title = {Effect of point-spread function reconstruction for indeterminate PSMA-RADS-3A lesions on PSMA-targeted PET imaging of men with prostate cancer}, series = {Diagnostics}, volume = {11}, journal = {Diagnostics}, number = {4}, issn = {2075-4418}, doi = {10.3390/diagnostics11040665}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236528}, year = {2021}, abstract = {Purpose: Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is emerging as an important modality for imaging patients with prostate cancer (PCa). As with any imaging modality, indeterminate findings will arise. The PSMA reporting and data system (PSMA-RADS) version 1.0 codifies indeterminate soft tissue findings with the PSMA-RADS-3A moniker. We investigated the role of point-spread function (PSF) reconstructions on categorization of PSMA-RADS-3A lesions. Methods: This was a post hoc analysis of an institutional review board approved prospective trial. Around 60 min after the administration of 333 MBq (9 mCi) of PSMA-targeted \(^{18}\)F-DCFPyL, patients underwent PET/computed tomography (CT) acquisitions from the mid-thighs to the skull vertex. The PET data were reconstructed with and without PSF. Scans were categorized according to PSMA-RADS version 1.0, and all PSMA-RADS-3A lesions on non-PSF images were re-evaluated to determine if any could be re-categorized as PSMA-RADS-4. The maximum standardized uptake values (SUVs) of the lesions, mean SUVs of blood pool, and the ratios of those values were determined. Results: A total of 171 PSMA-RADS-3A lesions were identified in 30 patients for whom both PSF reconstructions and cross-sectional imaging follow-up were available. A total of 13/171 (7.6\%) were re-categorized as PSMA-RADS-4 lesions with PSF reconstructions. A total of 112/171 (65.5\%) were found on follow-up to be true positive for PCa, with all 13 of the re-categorized lesions being true positive on follow-up. The lesions that were re-categorized trended towards having higher SUV\(_{max}\)-lesion and SUV\(_{max}\)-lesion/SUV\(_{mean}\)-blood-pool metrics, although these relationships were not statistically significant. Conclusions: The use of PSF reconstructions for \(^{18}\)F-DCFPyL PET can allow the appropriate re-categorization of a small number of indeterminate PSMA-RADS-3A soft tissue lesions as more definitive PSMA-RADS-4 lesions. The routine use of PSF reconstructions for PSMA-targeted PET may be of value at those sites that utilize this technology.}, language = {en} } @article{WeichRogollGawlasetal.2021, author = {Weich, Alexander and Rogoll, Dorothee and Gawlas, Sophia and Mayer, Lars and Weich, Wolfgang and Pongracz, Judit and Kudlich, Theodor and Meining, Alexander and Scheurlen, Michael}, title = {Wnt/β-catenin signaling regulates CXCR4 expression and [\(^{68}\)Ga] Pentixafor internalization in neuroendocrine tumor cells}, series = {Diagnostics}, volume = {11}, journal = {Diagnostics}, number = {2}, issn = {2075-4418}, doi = {10.3390/diagnostics11020367}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228914}, year = {2021}, abstract = {Loss of Somatostatin Receptor 2 (SSTR2) expression and rising CXC Chemokine Receptor Type 4 (CXCR4) expression are associated with dedifferentiation in neuroendocrine tumors (NET). In NET, CXCR4 expression is associated with enhanced metastatic and invasive potential and worse prognosis but might be a theragnostic target. Likewise, activation of Wnt/β-catenin signaling may promote a more aggressive phenotype in NET. We hypothesized an interaction of the Wnt/β-catenin pathway with CXCR4 expression and function in NET. The NET cell lines BON-1, QGP-1, and MS-18 were exposed to Wnt inhibitors (5-aza-CdR, quercetin, and niclosamide) or the Wnt activator LiCl. The expressions of Wnt pathway genes and of CXCR4 were studied by qRT-PCR, Western blot, and immunohistochemistry. The effects of Wnt modulators on uptake of the CXCR4 ligand [\(^{68}\)Ga] Pentixafor were measured. The Wnt activator LiCl induced upregulation of CXCR4 and Wnt target gene expression. Treatment with the Wnt inhibitors had opposite effects. LiCl significantly increased [\(^{68}\)Ga] Pentixafor uptake, while treatment with Wnt inhibitors decreased radiopeptide uptake. Wnt pathway modulation influences CXCR4 expression and function in NET cell lines. Wnt modulation might be a tool to enhance the efficacy of CXCR4-directed therapies in NET or to inhibit CXCR4-dependent proliferative signaling. The underlying mechanisms for the interaction of the Wnt pathway with CXCR4 expression and function have yet to be clarified.}, language = {en} } @article{DicksonEberleinLassmann2022, author = {Dickson, John and Eberlein, Uta and Lassmann, Michael}, title = {The effect of modern PET technology and techniques on the EANM paediatric dosage card}, series = {European Journal of Nuclear Medicine and Molecular Imaging}, volume = {49}, journal = {European Journal of Nuclear Medicine and Molecular Imaging}, number = {6}, issn = {1619-7089}, doi = {10.1007/s00259-021-05635-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265624}, pages = {1964-1969}, year = {2022}, abstract = {Aim Recent advancements in PET technology have brought with it significant improvements in PET performance and image quality. In particular, the extension of the axial field of view of PET systems, and the introduction of semiconductor technology into the PET detector, initially for PET/MR, and more recently available long-field-of-view PET/CT systems (≥ 25 cm) have brought a step change improvement in the sensitivity of PET scanners. Given the requirement to limit paediatric doses, this increase in sensitivity is extremely welcome for the imaging of children and young people. This is even more relevant with PET/MR, where the lack of CT exposures brings further dose reduction benefits to this population. In this short article, we give some details around the benefits around new PET technology including PET/MR and its implications on the EANM paediatric dosage card. Material and methods Reflecting on EANM adult guidance on injected activities, and making reference to bed overlap and the concept of MBq.min bed\(^{-1}\) kg\(^{-1}\), we use published data on image quality from PET/MR systems to update the paediatric dosage card for PET/MR and extended axial field of view (≥ 25 cm) PET/CT systems. However, this communication does not cover the expansion of paediatric dosing for the half-body and total-body scanners that have recently come to market. Results In analogy to the existing EANM dosage card, new parameters for the EANM paediatric dosage card were developed (class B, baseline value: 10.7 MBq, minimum recommended activity 10 MBq). The recommended administered activities for the systems considered in this communication range from 11 MBq [\(^{18}\)F]FDG for a child with a weight of 3 kg to 149 MBq [\(^{18}\)F]FDG for a paediatric patient weight of 68 kg, assuming a scan of 3 min per bed position. The mean effective dose over all ages (1 year and older) is 2.85 mSv. Conclusion With this, recommendations for paediatric dosing are given for systems that have not been considered previously.}, language = {en} } @article{HeinzeSchirbelNannenetal.2021, author = {Heinze, Britta and Schirbel, Andreas and Nannen, Lukas and Michelmann, David and Hartrampf, Philipp E. and Bluemel, Christina and Schneider, Magdalena and Herrmann, Ken and Haenscheid, Heribert and Fassnacht, Martin and Buck, Andreas K. and Hahner, Stefanie}, title = {Novel CYP11B-ligand [\(^{123/131}\)I]IMAZA as promising theranostic tool for adrenocortical tumors: comprehensive preclinical characterization and first clinical experience}, series = {European Journal of Nuclear Medicine and Molecular Imaging}, volume = {49}, journal = {European Journal of Nuclear Medicine and Molecular Imaging}, number = {1}, issn = {1619-7089}, doi = {10.1007/s00259-021-05477-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265606}, pages = {301-310}, year = {2021}, abstract = {Purpose Adrenal tumors represent a diagnostic and therapeutic challenge. Promising results have been obtained through targeting the cytochrome P450 enzymes CYP11B1 and CYP11B2 for molecular imaging, and [\(^{123/131}\)I]iodometomidate ([\(^{123/131}\)I]IMTO) has even been successfully introduced as a theranostic agent. As this radiopharmaceutical shows rapid metabolic inactivation, we aimed at developing new improved tracers. Methods Several IMTO derivatives were newly designed by replacing the unstable methyl ester by different carboxylic esters or amides. The inhibition of aldosterone and cortisol synthesis was tested in different adrenocortical cell lines. The corresponding radiolabeled compounds were assessed regarding their stability, in vitro cell uptake, in vivo biodistribution in mice, and their binding specificity to cryosections of human adrenocortical and non-adrenocortical tissue. Furthermore, a first investigation was performed in patients with known metastatic adrenal cancer using both [\(^{123}\)I]IMTO and the most promising compound (R)-1-[1-(4-[\(^{123/}\)I]iodophenyl)ethyl]-1H-imidazole-5-carboxylic acid azetidinylamide ([\(^{123}\)I]IMAZA) for scintigraphy. Subsequently, a first endoradiotherapy with [\(^{131}\)I]IMAZA in one of these patients was performed. Results We identified three analogues to IMTO with high-affinity binding to the target enzymes and comparable or higher metabolic stability and very high and specific accumulation in adrenocortical cells in vitro and in vivo. Labeled IMAZA exhibited superior pharmacokinetic and imaging properties compared to IMTO in mice and 3 patients, too. An endoradiotherapy with [\(^{131}\)I]IMAZA induced a 21-month progression-free interval in a patient with rapidly progressing ACC prior this therapy. Conclusion We developed the new radiopharmaceutical [\(^{123/131}\)I]IMAZA with superior properties compared to the reference compound IMTO and promising first experiences in humans.}, language = {en} } @article{DrozdSaenkoBranovanetal.2021, author = {Drozd, Valentina and Saenko, Vladimir and Branovan, Daniel I. and Brown, Kate and Yamashita, Shunichi and Reiners, Christoph}, title = {A search for causes of rising incidence of differentiated thyroid cancer in children and adolescents after Chernobyl and Fukushima: comparison of the clinical features and their relevance for treatment and prognosis}, series = {International Journal of Environmental Research and Public Health}, volume = {18}, journal = {International Journal of Environmental Research and Public Health}, number = {7}, issn = {1660-4601}, doi = {10.3390/ijerph18073444}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234247}, year = {2021}, abstract = {The incidence of differentiated thyroid cancer (DTC) is steadily increasing globally. Epidemiologists usually explain this global upsurge as the result of new diagnostic modalities, screening and overdiagnosis as well as results of lifestyle changes including obesity and comorbidity. However, there is evidence that there is a real increase of DTC incidence worldwide in all age groups. Here, we review studies on pediatric DTC after nuclear accidents in Belarus after Chernobyl and Japan after Fukushima as compared to cohorts without radiation exposure of those two countries. According to the Chernobyl data, radiation-induced DTC may be characterized by a lag time of 4-5 years until detection, a higher incidence in boys, in children of youngest age, extrathyroidal extension and distant metastases. Radiation doses to the thyroid were considerably lower by appr. two orders of magnitude in children and adolescents exposed to Fukushima as compared to Chernobyl. In DTC patients detected after Fukushima by population-based screening, most of those characteristics were not reported, which can be taken as proof against the hypothesis, that radiation is the (main) cause of those tumors. However, roughly 80\% of the Fukushima cases presented with tumor stages higher than microcarcinomas pT1a and 80\% with lymph node metastases pN1. Mortality rates in pediatric DTC patients are generally very low, even at higher tumor stages. However, those cases considered to be clinically relevant should be followed-up carefully after treatment because of the risk of recurrencies which is expected to be not negligible. Considering that thyroid doses from the Fukushima accident were quite small, it makes sense to assess the role of other environmental and lifestyle-related factors in thyroid carcinogenesis. Well-designed studies with assessment of radiation doses from medical procedures and exposure to confounders/modifiers from the environment as e.g., nitrate are required to quantify their combined effect on thyroid cancer risk.}, language = {en} } @article{GentzschChenSpatzetal.2021, author = {Gentzsch, Christian and Chen, Xinyu and Spatz, Philipp and Košak, Urban and Knez, Damijan and Nose, Naoko and Gobec, Stanislav and Higuchi, Takahiro and Decker, Michael}, title = {Synthesis and Initial Characterization of a Reversible, Selective \(^{18}\)F-Labeled Radiotracer for Human Butyrylcholinesterase}, series = {Molecular Imaging and Biology}, volume = {23}, journal = {Molecular Imaging and Biology}, number = {4}, issn = {1860-2002}, doi = {10.1007/s11307-021-01584-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-269870}, pages = {505-515}, year = {2021}, abstract = {Purpose A neuropathological hallmark of Alzheimer's disease (AD) is the presence of amyloid-β (Aβ) plaques in the brain, which are observed in a significant number of cognitively normal, older adults as well. In AD, butyrylcholinesterase (BChE) becomes associated with A\(_{β}\) aggregates, making it a promising target for imaging probes to support diagnosis of AD. In this study, we present the synthesis, radiochemistry, in vitro and preliminary ex and in vivo investigations of a selective, reversible BChE inhibitor as PET-tracer for evaluation as an AD diagnostic. Procedures Radiolabeling of the inhibitor was achieved by fluorination of a respective tosylated precursor using K[\(^{18}\)F]. IC\(_{50}\) values of the fluorinated compound were obtained in a colorimetric assay using recombinant, human (h) BChE. Dissociation constants were determined by measuring hBChE activity in the presence of different concentrations of inhibitor. Results Radiofluorination of the tosylate precursor gave the desired radiotracer in an average radiochemical yield of 20 ± 3 \%. Identity and > 95.5 \% radiochemical purity were confirmed by HPLC and TLC autoradiography. The inhibitory potency determined in Ellman's assay gave an IC\(_{50}\) value of 118.3 ± 19.6 nM. Dissociation constants measured in kinetic experiments revealed lower affinity of the inhibitor for binding to the acylated enzyme (K2 = 68.0 nM) in comparison to the free enzyme (K\(_{1}\) = 32.9 nM). Conclusions The reversibly acting, selective radiotracer is synthetically easily accessible and retains promising activity and binding potential on hBChE. Radiosynthesis with \(^{18}\)F labeling of tosylates was feasible in a reasonable time frame and good radiochemical yield.}, language = {en} } @article{GramGenslerWinteretal.2022, author = {Gram, Maximilian and Gensler, Daniel and Winter, Patrick and Seethaler, Michael and Arias-Loza, Paula Anahi and Oberberger, Johannes and Jakob, Peter Michael and Nordbeck, Peter}, title = {Fast myocardial T\(_{1P}\) mapping in mice using k-space weighted image contrast and a Bloch simulation-optimized radial sampling pattern}, series = {Magnetic Resonance Materials in Physics, Biology and Medicine}, volume = {35}, journal = {Magnetic Resonance Materials in Physics, Biology and Medicine}, number = {2}, issn = {1352-8661}, doi = {10.1007/s10334-021-00951-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268903}, pages = {325-340}, year = {2022}, abstract = {Purpose T\(_{1P}\) dispersion quantification can potentially be used as a cardiac magnetic resonance index for sensitive detection of myocardial fibrosis without the need of contrast agents. However, dispersion quantification is still a major challenge, because T\(_{1P}\) mapping for different spin lock amplitudes is a very time consuming process. This study aims to develop a fast and accurate T\(_{1P}\) mapping sequence, which paves the way to cardiac T1ρ dispersion quantification within the limited measurement time of an in vivo study in small animals. Methods A radial spin lock sequence was developed using a Bloch simulation-optimized sampling pattern and a view-sharing method for image reconstruction. For validation, phantom measurements with a conventional sampling pattern and a gold standard sequence were compared to examine T\(_{1P}\) quantification accuracy. The in vivo validation of T\(_{1P}\) mapping was performed in N = 10 mice and in a reproduction study in a single animal, in which ten maps were acquired in direct succession. Finally, the feasibility of myocardial dispersion quantification was tested in one animal. Results The Bloch simulation-based sampling shows considerably higher image quality as well as improved T\(_{1P}\) quantification accuracy (+ 56\%) and precision (+ 49\%) compared to conventional sampling. Compared to the gold standard sequence, a mean deviation of - 0.46 ± 1.84\% was observed. The in vivo measurements proved high reproducibility of myocardial T\(_{1P}\) mapping. The mean T\(_{1P}\) in the left ventricle was 39.5 ± 1.2 ms for different animals and the maximum deviation was 2.1\% in the successive measurements. The myocardial T\(_{1P}\) dispersion slope, which was measured for the first time in one animal, could be determined to be 4.76 ± 0.23 ms/kHz. Conclusion This new and fast T\(_{1P}\) quantification technique enables high-resolution myocardial T\(_{1P}\) mapping and even dispersion quantification within the limited time of an in vivo study and could, therefore, be a reliable tool for improved tissue characterization.}, language = {en} } @article{HendricksLenschowKroissetal.2021, author = {Hendricks, Anne and Lenschow, Christina and Kroiss, Matthias and Buck, Andreas and Kickuth, Ralph and Germer, Christoph-Thomas and Schlegel, Nicolas}, title = {Evaluation of diagnostic efficacy for localization of parathyroid adenoma in patients with primary hyperparathyroidism undergoing repeat surgery}, series = {Langenbeck's Archives of Surgery}, volume = {406}, journal = {Langenbeck's Archives of Surgery}, number = {5}, issn = {1435-2451}, doi = {10.1007/s00423-021-02191-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267520}, pages = {1615-1624}, year = {2021}, abstract = {Purpose Repeat surgery in patients with primary hyperparathyroidism (pHPT) is associated with an increased risk of complications and failure. This stresses the need for optimized strategies to accurately localize a parathyroid adenoma before repeat surgery is performed. However, evidence on the extent of required diagnostics for a structured approach is sparse. Methods A retrospective single-center evaluation of 28 patients with an indication for surgery due to pHPT and previous thyroid or parathyroid surgery was performed. Diagnostic workup, surgical approach, and outcome in terms of complications and successful removement of parathyroid adenoma with biochemical cure were evaluated. Results Neck ultrasound, sestamibi scintigraphy, C11-methionine PET-CT, and selective parathyroid hormone venous sampling, but not MRI imaging, effectively detected the presence of a parathyroid adenoma with high positive predictive values. Biochemical cure was revealed by normalization of calcium and parathormone levels 24-48h after surgery and was achieved in 26/28 patients (92.9\%) with an overall low rate of complications. Concordant localization by at least two diagnostic modalities enabled focused surgery with success rates of 100\%, whereas inconclusive localization significantly increased the rate of bilateral explorations and significantly reduced the rate of biochemical cure to 80\%. Conclusion These findings suggest that two concordant diagnostic modalities are sufficient to accurately localize parathyroid adenoma before repeat surgery for pHPT. In cases of poor localization, extended diagnostic procedures are warranted to enhance surgical success rates. We suggest an algorithm for better orientation when repeat surgery is intended in patients with pHPT.}, language = {en} } @article{MoralesLozanoVieringSamnicketal.2020, author = {Morales-Lozano, Maria I. and Viering, Oliver and Samnick, Samuel and Rodriguez-Otero, Paula and Buck, Andreas K. and Marcos-Jubilar, Maria and Rasche, Leo and Prieto, Elena and Kort{\"u}m, K. Martin and San-Miguel, Jesus and Garcia-Velloso, Maria J. and Lapa, Constantin}, title = {\(^{18}\)F-FDG and \(^{11}\)C-methionine PET/CT in newly diagnosed multiple myeloma patients: comparison of volume-based PET biomarkers}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {4}, issn = {2072-6694}, doi = {10.3390/cancers12041042}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203686}, year = {2020}, abstract = {\(^{11}\)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-na{\"i}ve 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.}, language = {en} } @article{TranGiaDenisBacelarFerreiraetal.2021, author = {Tran-Gia, Johannes and Denis-Bacelar, Ana M. and Ferreira, Kelley M. and Robinson, Andrew P. and Calvert, Nicholas and Fenwick, Andrew J. and Finocchiaro, Domenico and Fioroni, Federica and Grassi, Elisa and Heetun, Warda and Jewitt, Stephanie J. and Kotzassarlidou, Maria and Ljungberg, Michael and McGowan, Daniel R. and Scott, Nathaniel and Scuffham, James and Gleisner, Katarina Sj{\"o}green and Tipping, Jill and Wevrett, Jill and Lassmann, Michael}, title = {A multicentre and multi-national evaluation of the accuracy of quantitative Lu-177 SPECT/CT imaging performed within the MRTDosimetry project}, series = {EJNMMI Physics}, volume = {8}, journal = {EJNMMI Physics}, doi = {10.1186/s40658-021-00397-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270380}, year = {2021}, abstract = {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.}, language = {en} } @article{EisslerWernerAriasLozaetal.2021, author = {Eissler, Cristoph and Werner, Rudolf A. and Arias-Loza, Paula and Nose, Naoko and Chen, Xinyu and Pomper, Martin G. and Rowe, Steven P. and Lapa, Constantin and Buck, Andreas K. and Higuchi, Takahiro}, title = {The number of frames on ECG-gated \(^{18}\)F-FDG small animal PET has a significant impact on LV systolic and diastolic functional parameters}, series = {Molecular Imaging}, volume = {2021}, journal = {Molecular Imaging}, doi = {10.1155/2021/4629459}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265778}, year = {2021}, abstract = {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.}, language = {en} } @article{ScherthanLeeMausetal.2019, author = {Scherthan, Harry and Lee, Jin-Ho and Maus, Emanuel and Schumann, Sarah and Muhtadi, Razan and Chojowski, Robert and Port, Matthias and Lassmann, Michael and Bestvater, Felix and Hausmann, Michael}, title = {Nanostructure of clustered DNA damage in leukocytes after in-solution irradiation with the alpha emitter Ra-223}, series = {Cancers}, volume = {11}, journal = {Cancers}, number = {12}, issn = {2072-6694}, doi = {10.3390/cancers11121877}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193038}, year = {2019}, abstract = {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.}, language = {en} } @article{AertsEberleinHolmetal.2021, author = {Aerts, An and Eberlein, Uta and Holm, S{\"o}ren and Hustinx, Roland and Konijnenberg, Mark and Strigari, Lidia and van Leeuwen, Fijs W. B. and Glatting, Gerhard and Lassmann, Michael}, title = {EANM position paper on the role of radiobiology in nuclear medicine}, series = {European Journal of Nuclear Medicine and Molecular Imaging}, volume = {48}, journal = {European Journal of Nuclear Medicine and Molecular Imaging}, number = {11}, doi = {10.1007/s00259-021-05345-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265595}, pages = {3365-3377}, year = {2021}, abstract = {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.}, language = {en} } @article{NoseNogamiKoshinoetal.2021, author = {Nose, Naoko and Nogami, Suguru and Koshino, Kazuhiro and Chen, Xinyu and Werner, Rudolf A. and Kashima, Soki and Rowe, Steven P. and Lapa, Constantin and Fukuchi, Kazuki and Higuchi, Takahiro}, title = {[18F]FDG-labelled stem cell PET imaging in different route of administrations and multiple animal species}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-90383-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260590}, year = {2021}, abstract = {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.}, language = {en} } @article{ToyamaWernerRuizBedoyaetal.2021, author = {Toyama, Yoshitaka and Werner, Rudolf A. and Ruiz-Bedoya, Camilo A. and Ordonez, Alvaro A. and Takase, Kei and Lapa, Constantin and Jain, Sanjay K. and Pomper, Martin G. and Rowe, Steven P. and Higuchi, Takahiro}, title = {Current and future perspectives on functional molecular imaging in nephro-urology: theranostics on the horizon}, series = {Theranostics}, volume = {11}, journal = {Theranostics}, number = {12}, doi = {10.7150/thno.58682}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260090}, pages = {6105-6119}, year = {2021}, abstract = {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.}, language = {en} } @article{BrumbergKuzkinaLapaetal.2021, author = {Brumberg, Joachim and Kuzkina, Anastasia and Lapa, Constantin and Mammadova, Sona and Buck, Andreas and Volkmann, Jens and Sommer, Claudia and Isaias, Ioannis U. and Doppler, Kathrin}, title = {Dermal and cardiac autonomic fiber involvement in Parkinson's disease and multiple system atrophy}, series = {Neurobiology of Disease}, volume = {153}, journal = {Neurobiology of Disease}, doi = {10.1016/j.nbd.2021.105332}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260061}, pages = {105332}, year = {2021}, abstract = {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.}, language = {en} } @article{SchumannScherthanPfestroffetal.2021, author = {Schumann, S. and Scherthan, H. and Pfestroff, K. and Schoof, S. and Pfestroff, A. and Hartrampf, P. and Hasenauer, N. and Buck, A. K. and Luster, M. and Port, M. and Lassmann, M. and Eberlein, U.}, title = {DNA damage and repair in peripheral blood mononuclear cells after internal ex vivo irradiation of patient blood with \(^{131}\)I}, series = {European Journal of Nuclear Medicine and Molecular Imaging}, journal = {European Journal of Nuclear Medicine and Molecular Imaging}, doi = {10.1007/s00259-021-05605-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258863}, year = {2021}, abstract = {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.}, language = {en} } @article{SchadtIsraelSamnick2021, author = {Schadt, Fabian and Israel, Ina and Samnick, Samuel}, title = {Development and Validation of a Semi-Automated, Preclinical, MRI-Template Based PET Image Data Analysis Tool for Rodents}, series = {Frontiers in Neuroinformatics}, volume = {15}, journal = {Frontiers in Neuroinformatics}, issn = {1662-5196}, doi = {10.3389/fninf.2021.639643}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-240289}, year = {2021}, abstract = {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.}, language = {en} }