TY - JOUR A1 - Wevrett, Jill A1 - Fenwick, Andrew A1 - Scuffham, James A1 - Johansson, Lena A1 - Gear, Jonathan A1 - Schlögl, Susanne A1 - Segbers, Marcel A1 - Sjögreen-Gleisner, Katarina A1 - Solný, Pavel A1 - Lassmann, Michael A1 - Tipping, Jill A1 - Nisbet, Andrew T1 - Inter-comparison of quantitative imaging of lutetium-177 (\(^{177}\)Lu) in European hospitals JF - EJNMMI Physics N2 - Background This inter-comparison exercise was performed to demonstrate the variability of quantitative SPECT/CT imaging for lutetium-177 (\(^{177}\)Lu) in current clinical practice. Our aim was to assess the feasibility of using international inter-comparison exercises as a means to ensure consistency between clinical sites whilst enabling the sites to use their own choice of quantitative imaging protocols, specific to their systems. Dual-compartment concentric spherical sources of accurately known activity concentrations were prepared and sent to seven European clinical sites. The site staff were not aware of the true volumes or activity within the sources—they performed SPECT/CT imaging of the source, positioned within a water-filled phantom, using their own choice of parameters and reported their estimate of the activities within the source. Results The volumes reported by the participants for the inner section of the source were all within 29% of the true value and within 60% of the true value for the outer section. The activities reported by the participants for the inner section of the source were all within 20% of the true value, whilst those reported for the outer section were up to 83% different to the true value. Conclusions A variety of calibration and segmentation methods were used by the participants for this exercise which demonstrated the variability of quantitative imaging across clinical sites. This paper presents a method to assess consistency between sites using different calibration and segmentation methods. KW - Lutetium KW - Lu-177 KW - SPECT/CT KW - quantitative imaging KW - PRRT KW - molecular radiotherapy Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233658 VL - 5 ER - TY - JOUR A1 - Wester, Hans Jürgen A1 - Keller, Ulrich A1 - Schottelius, Margret A1 - Beer, Ambros A1 - Philipp-Abbrederis, Kathrin A1 - Hoffmann, Frauke A1 - Šimeček, Jakub A1 - Gerngross, Carlos A1 - Lassmann, Michael A1 - Herrmann, Ken A1 - Pellegata, Natalia A1 - Rudelius, Martina A1 - Kessler, Horst A1 - Schwaiger, Markus T1 - Disclosing the CXCR4 expression in lymphoproliferative diseases by targeted molecular imaging JF - Theranostics N2 - Chemokine ligand-receptor interactions play a pivotal role in cell attraction and cellular trafficking, both in normal tissue homeostasis and in disease. In cancer, chemokine receptor-4 (CXCR4) expression is an adverse prognostic factor. Early clinical studies suggest that targeting CXCR4 with suitable high-affinity antagonists might be a novel means for therapy. In addition to the preclinical evaluation of [\(^{68}\)Ga]Pentixafor in mice bearing human lymphoma xenografts as an exemplary CXCR4-expressing tumor entity, we report on the first clinical applications of [\(^{68}\)Ga]Pentixafor-Positron Emission Tomography as a powerful method for CXCR4 imaging in cancer patients. [\(^{68}\)Ga]Pentixafor binds with high affinity and selectivity to human CXCR4 and exhibits a favorable dosimetry. [\(^{68}\)Ga]Pentixafor-PET provides images with excellent specificity and contrast. This non-invasive imaging technology for quantitative assessment of CXCR4 expression allows to further elucidate the role of CXCR4/CXCL12 ligand interaction in the pathogenesis and treatment of cancer, cardiovascular diseases and autoimmune and inflammatory disorders. KW - acute myeloid leukemia KW - prognostic value KW - therapeutic target KW - chemokine receptor KW - CXCR4 KW - lymphoma KW - in vivo imaging KW - positron emission tomography Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144537 VL - 5 IS - 6 ER - TY - CHAP A1 - Werner, Rudolf A1 - Lapa, Constantin A1 - Buck, Andreas A1 - Lassmann, Michael A1 - Hänscheid, Heribert T1 - Less is sometimes more – Accurate Dose Mapping after Endoradiotherapy with \(^{177}\)Lu-DOTATATE/-TOC by One-Single Measurement after 96 h T2 - Journal of Nuclear Medicine N2 - No abstract available. KW - Neuroendocrine Tumor KW - theranostics KW - 177Lu-DOTATATE KW - 177Lu-DOTATOC KW - PRRT Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161168 UR - http://jnm.snmjournals.org/content/58/supplement_1/247.abstract SN - 0161-5505 N1 - This research was originally published in JNM. Werner R.A., Lapa C., Buck A.K., Lassmann M., Hänscheid H.Less is sometimes more – Accurate Dose Mapping after Endoradiotherapy with 177Lu-DOTATATE/-TOC by One-Single Measurement after 96 h. J Nucl Med May 1, 2017 vol. 58 no. supplement 1:247. © SNMMI VL - 58 IS - No. Supplement 1 PB - Society of Nuclear Medicine and Molecular Imaging ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Weich, Alexander A1 - Higuchi, Takahiro A1 - Schmid, Jan S. A1 - Schirbel, Andreas A1 - Lassmann, Michael A1 - Wild, Vanessa A1 - Rudelius, Martina A1 - Kudlich, Theodor A1 - Herrmann, Ken A1 - Scheurlen, Michael A1 - Buck, Andreas K. A1 - Kropf, Saskia A1 - Wester, Hans-Jürgen A1 - Lapa, Constantin T1 - Imaging of Chemokine Receptor 4 Expression in Neuroendocrine Tumors - a Triple Tracer Comparative Approach JF - Theranostics N2 - C-X-C motif chemokine receptor 4 (CXCR4) and somatostatin receptors (SSTR) are overexpressed in gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). In this study, we aimed to elucidate the feasibility of non-invasive CXCR4 positron emission tomography/computed tomography (PET/CT) imaging in GEP-NET patients using [\(^{68}\)Ga]Pentixafor in comparison to \(^{68}\)Ga-DOTA-D-Phe-Tyr3-octreotide ([\(^{68}\)Ga]DOTATOC) and \(^{18}\)F-fluorodeoxyglucose ([\(^{18}\)F]FDG). Twelve patients with histologically proven GEP-NET (3xG1, 4xG2, 5xG3) underwent [\(^{68}\)Ga]DOTATOC, [\(^{18}\)F]FDG, and [\(^{68}\)Ga]Pentixafor PET/CT for staging and planning of the therapeutic management. Scans were analyzed on a patient as well as on a lesion basis and compared to immunohistochemical staining patterns of CXCR4 and somatostatin receptors SSTR2a and SSTR5. [\(^{68}\)Ga]Pentixafor visualized tumor lesions in 6/12 subjects, whereas [\(^{18}\)F]FDG revealed sites of disease in 10/12 and [\(^{68}\)Ga]DOTATOC in 11/12 patients, respectively. Regarding sensitivity, SSTR-directed PET was the superior imaging modality in all G1 and G2 NET. CXCR4-directed PET was negative in all G1 NET. In contrast, 50% of G2 and 80% of G3 patients exhibited [\(^{68}\)Ga]Pentixafor-positive tumor lesions. Whereas CXCR4 seems to play only a limited role in detecting well-differentiated NET, increasing receptor expression could be non-invasively observed with increasing tumor grade. Thus, [\(^{68}\)Ga]Pentixafor PET/CT might serve as non-invasive read-out for evaluating the possibility of CXCR4-directed endoradiotherapy in advanced dedifferentiated SSTR-negative tumors. KW - SSTR KW - peptide receptor radionuclide therapy KW - neuroendocrine tumor KW - [\(^{68}\)Ga]Pentixafor KW - CXCR4 KW - chemokine receptor KW - PET/CT KW - DOTATOC KW - PRRT KW - Positronen-Emissions-Tomografie Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158008 VL - 7 IS - 6 ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Beykan, Seval A1 - Higuchi, Takahiro A1 - Lückerath, Katharina A1 - Weich, Alexander A1 - Scheurlen, Michael A1 - Bluemel, Christina A1 - Herrmann, Ken A1 - Buck, Andreas K. A1 - Lassmann, Michael A1 - Lapa, Constantin A1 - Hänscheid, Heribert T1 - The impact of \(^{177}\)Lu-octreotide therapy on \(^{99m}\)Tc-MAG3 clearance is not predictive for late nephropathy JF - Oncotarget N2 - Peptide Receptor Radionuclide Therapy (PRRT) for the treatment of neuroendocrine tumors may lead to kidney deterioration. This study aimed to evaluate the suitability of \(^{99m}\)Tc-mercaptoacetyltriglycine (\(^{99m}\)Tc-MAG3) clearance for the early detection of PRRT-induced changes on tubular extraction (TE). TE rate (TER) was measured prior to 128 PRRT cycles (7.6±0.4 GBq \(^{177}\)Lu-octreotate/octreotide each) in 32 patients. TER reduction during PRRT was corrected for age-related decrease and analyzed for the potential to predict loss of glomerular filtration (GF). The GF rate (GFR) as measure for renal function was derived from serum creatinine. The mean TER was 234 ± 53 ml/min/1.73 m² before PRRT (baseline) and 221 ± 45 ml/min/1.73 m² after a median follow-up of 370 days. The age-corrected decrease (mean: -3%, range: -27% to +19%) did not reach significance (p=0.09) but significantly correlated with the baseline TER (Spearman p=-0.62, p<0.001). Patients with low baseline TER showed an improved TER after PRRT, high decreases were only observed in individuals with high baseline TER. Pre-therapeutic TER data were inferior to plasma creatinine-derived GFR estimates in predicting late nephropathy. TER assessed by \(^{99m}\)Tc-MAG3­clearance prior to and during PRRT is not suitable as early predictor of renal injury and an increased risk for late nephropathy. KW - renal scintigraphy KW - neuroendocrine tumor KW - 177Lu KW - MAG3 KW - PRRT Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177318 VL - 7 IS - 27 ER - TY - JOUR A1 - Tran-Gia, Johannes A1 - Denis-Bacelar, Ana M. A1 - Ferreira, Kelley M. A1 - Robinson, Andrew P. A1 - Calvert, Nicholas A1 - Fenwick, Andrew J. A1 - Finocchiaro, Domenico A1 - Fioroni, Federica A1 - Grassi, Elisa A1 - Heetun, Warda A1 - Jewitt, Stephanie J. A1 - Kotzassarlidou, Maria A1 - Ljungberg, Michael A1 - McGowan, Daniel R. A1 - Scott, Nathaniel A1 - Scuffham, James A1 - Gleisner, Katarina Sjögreen A1 - Tipping, Jill A1 - Wevrett, Jill A1 - Lassmann, Michael T1 - A multicentre and multi-national evaluation of the accuracy of quantitative Lu-177 SPECT/CT imaging performed within the MRTDosimetry project JF - EJNMMI Physics N2 - Purpose Patient-specific dosimetry is required to ensure the safety of molecular radiotherapy and to predict response. Dosimetry involves several steps, the first of which is the determination of the activity of the radiopharmaceutical taken up by an organ/lesion over time. As uncertainties propagate along each of the subsequent steps (integration of the time–activity curve, absorbed dose calculation), establishing a reliable activity quantification is essential. The MRTDosimetry project was a European initiative to bring together expertise in metrology and nuclear medicine research, with one main goal of standardizing quantitative \(^{177}\)Lu SPECT/CT imaging based on a calibration protocol developed and tested in a multicentre inter-comparison. This study presents the setup and results of this comparison exercise. Methods The inter-comparison included nine SPECT/CT systems. Each site performed a set of three measurements with the same setup (system, acquisition and reconstruction): (1) Determination of an image calibration for conversion from counts to activity concentration (large cylinder phantom), (2) determination of recovery coefficients for partial volume correction (IEC NEMA PET body phantom with sphere inserts), (3) validation of the established quantitative imaging setup using a 3D printed two-organ phantom (ICRP110-based kidney and spleen). In contrast to previous efforts, traceability of the activity measurement was required for each participant, and all participants were asked to calculate uncertainties for their SPECT-based activities. Results Similar combinations of imaging system and reconstruction lead to similar image calibration factors. The activity ratio results of the anthropomorphic phantom validation demonstrate significant harmonization of quantitative imaging performance between the sites with all sites falling within one standard deviation of the mean values for all inserts. Activity recovery was underestimated for total kidney, spleen, and kidney cortex, while it was overestimated for the medulla. Conclusion This international comparison exercise demonstrates that harmonization of quantitative SPECT/CT is feasible when following very specific instructions of a dedicated calibration protocol, as developed within the MRTDosimetry project. While quantitative imaging performance demonstrates significant harmonization, an over- and underestimation of the activity recovery highlights the limitations of any partial volume correction in the presence of spill-in and spill-out between two adjacent volumes of interests. KW - quantitative SPECT/CT KW - 177Lu SPECT/CT imaging KW - standardization of SPECT/CT imaging KW - harmonization of SPECT/CT imaging KW - international multicenter comparison exercise KW - traceability of SPECT/CT imaging KW - molecular radiotherapy (MRT) KW - 3D printing KW - phantom Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270380 VL - 8 ER - TY - JOUR A1 - Tran-Gia, Johannes A1 - Denis-Bacelar, Ana M. A1 - Ferreira, Kelley M. A1 - Robinson, Andrew P. A1 - Bobin, Christophe A1 - Bonney, Lara M. A1 - Calvert, Nicholas A1 - Collins, Sean M. A1 - Fenwick, Andrew J. A1 - Finocchiaro, Domenico A1 - Fioroni, Federica A1 - Giannopoulou, Katerina A1 - Grassi, Elisa A1 - Heetun, Warda A1 - Jewitt, Stephanie J. A1 - Kotzasarlidou, Maria A1 - Ljungberg, Michael A1 - Lourenço, Valérie A1 - McGowan, Daniel R. A1 - Mewburn-Crook, Jamie A1 - Sabot, Benoit A1 - Scuffham, James A1 - Sjögreen Gleisner, Katarina A1 - Solc, Jaroslav A1 - Thiam, Cheick A1 - Tipping, Jill A1 - Wevrett, Jill A1 - Lassmann, Michael T1 - On the use of solid 133Ba sources as surrogate for liquid 131I in SPECT/CT calibration: a European multi-centre evaluation JF - EJNMMI Physics N2 - Introduction Commissioning, calibration, and quality control procedures for nuclear medicine imaging systems are typically performed using hollow containers filled with radionuclide solutions. This leads to multiple sources of uncertainty, many of which can be overcome by using traceable, sealed, long-lived surrogate sources containing a radionuclide of comparable energies and emission probabilities. This study presents the results of a quantitative SPECT/CT imaging comparison exercise performed within the MRTDosimetry consortium to assess the feasibility of using 133Ba as a surrogate for 131I imaging. Materials and methods Two sets of four traceable 133Ba sources were produced at two National Metrology Institutes and encapsulated in 3D-printed cylinders (volume range 1.68–107.4 mL). Corresponding hollow cylinders to be filled with liquid 131I and a mounting baseplate for repeatable positioning within a Jaszczak phantom were also produced. A quantitative SPECT/CT imaging comparison exercise was conducted between seven members of the consortium (eight SPECT/CT systems from two major vendors) based on a standardised protocol. Each site had to perform three measurements with the two sets of 133Ba sources and liquid 131I. Results As anticipated, the 131I pseudo-image calibration factors (cps/MBq) were higher than those for 133Ba for all reconstructions and systems. A site-specific cross-calibration reduced the performance differences between both radionuclides with respect to a cross-calibration based on the ratio of emission probabilities from a median of 12–1.5%. The site-specific cross-calibration method also showed agreement between 133Ba and 131I for all cylinder volumes, which highlights the potential use of 133Ba sources to calculate recovery coefficients for partial volume correction. Conclusion This comparison exercise demonstrated that traceable solid 133Ba sources can be used as surrogate for liquid 131I imaging. The use of solid surrogate sources could solve the radiation protection problem inherent in the preparation of phantoms with 131I liquid activity solutions as well as reduce the measurement uncertainties in the activity. This is particularly relevant for stability measurements, which have to be carried out at regular intervals. KW - 133Ba KW - Barium-133 KW - 131I KW - radioiodine KW - solid surrogate source KW - quantitative SPECT/CT KW - comparison exercise KW - multi-centre KW - calibration Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357740 VL - 10 ER - TY - JOUR A1 - Schumann, Sarah A1 - Scherthan, Harry A1 - Frank, Torsten A1 - Lapa, Constantin A1 - Müller, Jessica A1 - Seifert, Simone A1 - Lassmann, Michael A1 - Eberlein, Uta T1 - DNA Damage in Blood Leukocytes of Prostate Cancer Patients Undergoing PET/CT Examinations with [\(^{68}\)Ga]Ga-PSMA I&T JF - Cancers N2 - The aim was to investigate the induction and repair of radiation-induced DNA double-strand breaks (DSBs) as a function of the absorbed dose to the blood of patients undergoing PET/CT examinations with [68Ga]Ga-PSMA. Blood samples were collected from 15 patients before and at four time points after [68Ga]Ga-PSMA administration, both before and after the PET/CT scan. Absorbed doses to the blood were calculated. In addition, blood samples with/without contrast agent from five volunteers were irradiated ex vivo by CT while measuring the absorbed dose. Leukocytes were isolated, fixed, and stained for co-localizing γ-H2AX+53BP1 DSB foci that were enumerated manually. In vivo, a significant increase in γ-H2AX+53BP1 foci compared to baseline was observed at all time points after administration, although the absorbed dose to the blood by 68Ga was below 4 mGy. Ex vivo, the increase in radiation-induced foci depended on the absorbed dose and the presence of contrast agent, which could have caused a dose enhancement. The CT-dose contribution for the patients was estimated at about 12 mGy using the ex vivo calibration. The additional number of DSB foci induced by CT, however, was comparable to the one induced by 68Ga. The significantly increased foci numbers after [68Ga]Ga-PSMA administration may suggest a possible low-dose hypersensitivity. KW - DNA double-strand breaks KW - γ-H2AX KW - 53BP1 KW - nuclear medicine KW - dosimetry KW - Ga-68 KW - PSMA KW - PET/CT KW - contrast agent KW - prostate cancer Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200585 SN - 2072-6694 VL - 12 IS - 2 ER - TY - JOUR A1 - Schumann, Sarah A1 - Eberlein, Uta A1 - Muhtadi, Razan A1 - Lassmann, Michael A1 - Scherthan, Harry T1 - DNA damage in leukocytes after internal ex-vivo irradiation of blood with the α-emitter Ra-223 JF - Scientific Reports N2 - Irradiation with high linear energy transfer α-emitters, like the clinically used Ra-223 dichloride, severely damages cells and induces complex DNA damage including closely spaced double-strand breaks (DSBs). As the hematopoietic system is an organ-at-risk for the treatment, knowledge about Ra-223-induced DNA damage in blood leukocytes is highly desirable. Therefore, 36 blood samples from six healthy volunteers were exposed ex-vivo (in solution) to different concentrations of Ra-223. Absorbed doses to the blood were calculated assuming local energy deposition of all α- and β-particles of the decay, ranging from 0 to 142 mGy. γ-H2AX + 53BP1 co-staining and analysis was performed in leukocytes isolated from the irradiated blood samples. For DNA damage quantification, leukocyte samples were screened for occurrence of α-induced DNA damage tracks and small γ-H2AX + 53BP1 DSB foci. This revealed a linear relationship between the frequency of α-induced γ-H2AX damage tracks and the absorbed dose to the blood, while the frequency of small γ-H2AX + 53BP1 DSB foci indicative of β-irradiation was similar to baseline values, being in agreement with a negligible β-contribution (3.7%) to the total absorbed dose to the blood. Our calibration curve will contribute to the biodosimetry of Ra-223-treated patients and early after incorporation of α-emitters. KW - alpha particles KW - blood KW - DNA Breaks KW - double-stranded KW - gamma rays KW - healthy volunteers KW - humans KW - leukocytes KW - radiation effects KW - radium Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175596 VL - 8 IS - 2286 ER - TY - JOUR A1 - Schuhmann, Sarah A1 - Eberlein, Uta A1 - Müller, Jessica A1 - Scherthan, Harry A1 - Lassmann, Michael T1 - Correlation of the absorbed dose to the blood and DNA damage in leukocytes after internal ex-vivo irradiation of blood samples with Ra-224 JF - EJNMMI Research N2 - Background: Irradiation with α-particles creates densely packed damage tracks along particle trajectories in exposed cells, including complex DNA damage and closely spaced double-strand breaks (DSBs) in hit nuclei. Here, we investigated the correlation of the absorbed dose to the blood and the number of α-induced DNA damage tracks elicited in human blood leukocytes after ex-vivo in-solution exposure with Ra-224. The aim was to compare the data to previously published data on Ra-223 and to investigate differences in DNA damage induction between the two radium isotopes. Results: Blood samples from three healthy volunteers were exposed ex-vivo to six different concentrations of Ra-224 dichloride. Absorbed doses to the blood were calculated assuming local energy deposition of all α- and β-particles of the Ra-224 decay chain, ranging from 0 to 127 mGy. γ-H2AX + 53BP1 DNA damage co-staining and analysis was performed on ethanol-fixed leukocytes isolated from the irradiated blood samples. For damage quantification, α-induced DNA damage tracks and small γ-H2AX + 53BP1 DSB foci were enumerated in the exposed leukocytes. This revealed a linear relationship between the frequency of α-induced γ-H2AX damage tracks and the absorbed dose to the blood, while the frequency of small γ-H2AX + 53BP1 DSB foci indicative of β-irradiation was similar to baseline values. Conclusions: Our data provide a first estimation of the DNA damage induced by Ra-224 in peripheral blood mononuclear cells. A comparison with our previously published Ra-223 data suggests that there is no difference in the induction of radiation-induced DNA damage between the two radium isotopes due to their similar decay properties. KW - 53BP1 KW - DNA damage KW - γ-H2AX KW - biological dosimetry KW - absorbed dose to the blood KW - α-emitter KW - Ra-224 Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176593 VL - 8 IS - 77 ER -