TY - JOUR A1 - Werner, Rudolf A1 - Hänscheid, Heribert A1 - Leal, Jeffrey P. A1 - Javadi, Mehrbod S. A1 - Higuchi, Takahiro A1 - Lodge, Martin A. A1 - Buck, Andreas K. A1 - Pomper, Martin G. A1 - Lapa, Constantin A1 - Rowe, Steven P. T1 - Impact of Tumor Burden on Quantitative [\(^{68}\)Ga]DOTATOC Biodistribution JF - Molecular Imaging and Biology N2 - Purpose: As has been previously reported, the somatostatin receptor (SSTR) imaging agent [\(^{68}\)Ga]-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotate ([\(^{68}\)Ga]DOTATATE) demonstrates lower uptake in normal organs in patients with a high neuroendocrine tumor (NET) burden. Given the higher SSTR affinity of [\(^{68}\)Ga]DOTATATE, we aimed to quantitatively investigate the biodistribution of [\(^{68}\)Ga]-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotide ([68Ga]DOTATOC) to determine a potential correlation between uptake in normal organs and NET burden. Procedures: Of the 44 included patients, 36/44 (82%) patients demonstrated suspicious radiotracer uptake on [\(^{68}\)Ga]DOTATOC positron emission tomography (PET)/x-ray computed tomography (CT). Volumes of Interest (VOIs) were defined for tumor lesions and normal organs (spleen, liver, kidneys, adrenals). Mean body weight corrected standardized uptake value (SUV\(_{mean}\)) for normal organs was assessed and was used to calculate the corresponding mean specific activity uptake (Upt: fraction of injected activity per kg of tissue). For the entire tumor burden, SUV\(_{mean}\), maximum standardized uptake value (SUV\(_{max}\)), and the total mass (TBM) was calculated and the decay corrected tumor fractional uptake (TBU) was assessed. A Spearman’s rank correlation coefficient was used to determine the correlations between normal organ uptake and tumor burden. Results: The median SUV\(_{mean}\) was 18.7 for the spleen (kidneys, 9.2; adrenals, 6.8; liver, 5.6). For tumor burden, the median values were SUV\(_{mean}\) 6.9, SUV\(_{max}\) 35.5, TBM 42.6g, and TBU 1.2%. With increasing volume of distribution, represented by lean body mass and body surface area (BSA), Upt decreased in kidneys, liver, and adrenal glands and SUV\(_{mean}\) increased in the spleen. Correlation improved only for both kidneys and adrenals when the influence of the tumor uptake on the activity available for organ uptake was taken into account by the factor 1/(1-TBU). TBU was neither predictive for SUV\(_{mean}\) nor for Upt in any of the organs. The distribution of organ Upt vs. BSA/(1-TBU) were not different for patients with minor TBU (<3%) vs. higher TBU (>7%), indicating that the correlations observed in the present study are explainable by the body size effect. High tumor mass and uptake mitigated against G1 NET. Conclusions: There is no significant impact on normal organ biodistribution with increasing tumor burden on [\(^{68}\)Ga]DOTATOC PET/CT. Potential implications include increased normal organ dose with [\(^{177}\)Lu-DOTA]\(^0\)-D-Phe\(^1\)-Tyr\(^3\)-Octreotide and decreased absolute lesion detection with [\(^{68}\)Ga]DOTATOC in high NET burden. KW - somatostatin receptor KW - Positronen-Emissions-Tomografie KW - quantification KW - [68Ga]DOTATOC KW - neuroendocrine tumor KW - SSTR-PET KW - theranostics Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170280 ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Habacha, Bilêl A1 - Lütje, Susanne A1 - Bundschuh, Lena A1 - Higuchi, Takahiro A1 - Hartrampf, Philipp A1 - Serfling, Sebastian E. A1 - Derlin, Thorsten A1 - Lapa, Constantin A1 - Buck, Andreas K. A1 - Essler, Markus A1 - Pienta, Kenneth J. A1 - Eisenberger, Mario A. A1 - Markowski, Mark C. A1 - Shinehouse, Laura A1 - AbdAllah, Rehab A1 - Salavati, Ali A1 - Lodge, Martin A. A1 - Pomper, Martin G. A1 - Gorin, Michael A. A1 - Bundschuh, Ralph A. A1 - Rowe, Steven P. T1 - High SUVs Have More Robust Repeatability in Patients with Metastatic Prostate Cancer: Results from a Prospective Test-Retest Cohort Imaged with \(^{18}\)F-DCFPyL JF - Molecular Imaging N2 - No abstract available. KW - SUV Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300748 VL - 2022 ER - TY - INPR A1 - Yin, Yafu A1 - Werner, Rudolf A. A1 - Higuchi, Takahiro A1 - Lapa, Constantin A1 - Pienta, Kenneth J. A1 - Pomper, Martin G. A1 - Gorin, Michael A. A1 - Rowe, Steven P. T1 - Follow-Up of Lesions with Equivocal Radiotracer Uptake on PSMA-Targeted PET in Patients with Prostate Cancer: Predictive Values of the PSMA-RADS-3A and PSMARADS- 3B Categories T2 - Journal of Nuclear Medicine N2 - Purpose: Prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging has become commonly utilized in patients with prostate cancer (PCa). The PSMA reporting and data system version 1.0 (PSMA-RADS version 1.0) categorizes lesions on the basis of the likelihood of PCa involvement, with PSMA-RADS-3A (soft tissue) and PSMA-RADS-3B (bone) lesions being indeterminate for the presence of disease. We retrospectively reviewed the imaging follow-up of such lesions to determine the rate at which they underwent changes suggestive of underlying PCa. Methods: PET/CT imaging with \(^{18}\)F-DCFPyL was carried out in 110 patients with PCa and lesions were categorized according to PSMA-RADS Version 1.0. 56/110 (50.9%) patients were determined to have indeterminate PSMA-RADS-3A or PSMA-RADS-3B lesions and 22/56 (39.3%) patients had adequate follow-up to be included in the analysis. The maximum standardized uptake values (SUV\(_{max}\)) of the lesions were obtained and the ratios of SUV\(_{max}\) of the lesions to SUV\(_{mean}\) of blood pool (SUV\(_{max}\)-lesion/SUV\(_{mean}\)-bloodpool) were calculated. Pre-determined criteria were used to evaluate the PSMA-RADS-3A and PSMA-RADS-3B lesions on follow-up imaging to determine if they demonstrated evidence of underlying malignancy. Results: A total of 46 lesions in 22 patients were considered indeterminate for PCa (i.e. PSMA-RADS-3A (32 lesions) or PSMA-RADS-3B (14 lesions)) and were evaluable on follow-up imaging. 27/46 (58.7%) lesions demonstrated changes on follow-up imaging consistent with the presence of underlying PCa at baseline. These lesions included 24/32 (75.0%) PSMA-RADS-3A lesions and 3/14 (21.4%) lesions categorized as PSMA-RADS-3B. The ranges of SUVmax and SUVmax-lesion/SUVmean-bloodpool overlapped between those lesions demonstrating changes consistent with malignancy on follow-up imaging and those lesions that remained unchanged on follow-up. Conclusion: PSMA-RADS-3A and PSMA-RADS-3B lesions are truly indeterminate in that proportions of findings in both categories demonstrate evidence of malignancy on follow-up imaging. Overall, PSMA-RADS-3A lesions are more likely than PSMA-RADS-3B lesions to represent sites of PCa and this information should be taken into when guiding patient therapy. KW - PSMA-RADS-3B KW - Positronen-Emissions-Tomografie KW - prostate-specific membrane antigen KW - prostate cancer KW - PSMA-targeted PET KW - PSMA-RADS-3A Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167594 SN - 0161-5505 N1 - This research was originally published in JNM. Yafu Yin, Rudolf A. Werner, Takahiro Higuchi, Constantin Lapa, Kenneth J. Pienta, Martin G. Pomper, Michael A. Gorin, Steven P. Rowe. Follow-Up of Lesions with Equivocal Radiotracer Uptake on PSMA-Targeted PET in Patients with Prostate Cancer: Predictive Values of the PSMA-RADS-3A and PSMA-RADS-3B Categories. J Nucl Med. 2019;60:511-516 © SNMMI. ER - TY - JOUR A1 - Weich, Alexander A1 - Werner, Rudolf A. A1 - Buck, Andreas K. A1 - Hartrampf, Philipp E. A1 - Serfling, Sebastian E. A1 - Scheurlen, Michael A1 - Wester, Hans-Jürgen A1 - Meining, Alexander A1 - Kircher, Stefan A1 - Higuchi, Takahiro A1 - Pomper, Martin G. A1 - Rowe, Steven P. A1 - Lapa, Constantin A1 - Kircher, Malte T1 - CXCR4-Directed PET/CT in Patients with Newly Diagnosed Neuroendocrine Carcinomas JF - Diagnostics N2 - We aimed to elucidate the diagnostic potential of the C-X-C motif chemokine receptor 4 (CXCR4)-directed positron emission tomography (PET) tracer \(^{68}\)Ga-Pentixafor in patients with poorly differentiated neuroendocrine carcinomas (NEC), relative to the established reference standard \(^{18}\)F-FDG PET/computed tomography (CT). In our database, we retrospectively identified 11 treatment-naïve patients with histologically proven NEC, who underwent \(^{18}\)F-FDG and CXCR4-directed PET/CT for staging and therapy planning. The images were analyzed on a per-patient and per-lesion basis and compared to immunohistochemical staining (IHC) of CXCR4 from PET-guided biopsies. \(^{68}\)Ga-Pentixafor visualized tumor lesions in 10/11 subjects, while \(^{18}\)F-FDG revealed sites of disease in all 11 patients. Although weak to moderate CXCR4 expression could be corroborated by IHC in 10/11 cases, \(^{18}\)F-FDG PET/CT detected significantly more tumor lesions (102 vs. 42; total lesions, n = 107; p < 0.001). Semi-quantitative analysis revealed markedly higher 18F-FDG uptake as compared to \(^{68}\)Ga-Pentixafor (maximum and mean standardized uptake values (SUV) and tumor-to-background ratios (TBR) of cancerous lesions, SUVmax: 12.8 ± 9.8 vs. 5.2 ± 3.7; SUVmean: 7.4 ± 5.4 vs. 3.1 ± 3.2, p < 0.001; and, TBR 7.2 ± 7.9 vs. 3.4 ± 3.0, p < 0.001). Non-invasive imaging of CXCR4 expression in NEC is inferior to the reference standard \(^{18}\)F-FDG PET/CT. KW - CXCR4 KW - NET KW - NEC KW - 68Ga-Pentixafor KW - 18F-FDG Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234231 SN - 2075-4418 VL - 11 IS - 4 ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Kircher, Stefan A1 - Higuchi, Takahiro A1 - Kircher, Malte A1 - Schirbel, Andreas A1 - Wester, Hans-Jürgen A1 - Buck, Andreas K. A1 - Pomper, Martin G. A1 - Rowe, Steven P. A1 - Lapa, Constantin T1 - CXCR4-directed imaging in solid tumors JF - Frontiers in Oncology N2 - Despite histological evidence in various solid tumor entities, available experience with CXCR4-directed diagnostics and endoradiotherapy mainly focuses on hematologic diseases. With the goal of expanding the application of CXCR4 theranostics to solid tumors, we aimed to elucidate the feasibility of CXCR4-targeted imaging in a variety of such neoplasms. Methods: Nineteen patients with newly diagnosed, treatment-naïve solid tumors including pancreatic adenocarcinoma or neuroendocrine tumor, cholangiocarcinoma, hepatocellular carcinoma, renal cell carcinoma, ovarian cancer, and prostate cancer underwent [\(^{68}\)Ga]Pentixafor PET/CT. CXCR4-mediated uptake was assessed both visually and semi-quantitatively by evaluation of maximum standardized uptake values (SUV\(_{max}\)) of both primary tumors and metastases. With physiologic liver uptake as reference, tumor-to-background ratios (TBR) were calculated. [\(^{68}\)Ga]Pentixafor findings were further compared to immunohistochemistry and [\(^{18}\)F]FDG PET/CT. Results: On [\(^{68}\)Ga]Pentixafor PET/CT, 10/19 (52.6%) primary tumors were visually detectable with a median SUVmax of 5.4 (range, 1.7–16.0) and a median TBR of 2.6 (range, 0.8–7.4), respectively. The highest level of radiotracer uptake was identified in a patient with cholangiocarcinoma (SUVmax, 16.0; TBR, 7.4). The relatively low uptake on [\(^{68}\)Ga]Pentixafor was also noted in metastases, exhibiting a median SUVmax of 4.5 (range, 2.3–8.8; TBR, 1.7; range, 1.0–4.1). A good correlation between uptake on [\(^{68}\)Ga]Pentixafor and histological derived CXCR4 expression was noted (R = 0.62, P < 0.05). In the 3 patients in whom [\(^{18}\)F]FDG PET/CT was available, [\(^{68}\)Ga]Pentixafor exhibited lower uptake in all lesions. Conclusions: In this cohort of newly diagnosed, treatment-naïve patients with solid malignancies, CXCR4 expression as detected by [\(^{68}\)Ga]Pentixafor-PET/CT and immunohistochemistry was rather moderate. Thus, CXCR4-directed imaging may not play a major role in the management of solid tumors in the majority of patients. KW - CXCR4 KW - [68Ga]Pentixafor KW - theranostics KW - solid tumors KW - chemokine receptor Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195678 SN - 2234-943X VL - 9 IS - 770 ER - TY - JOUR A1 - Toyama, Yoshitaka A1 - Werner, Rudolf A. A1 - Ruiz-Bedoya, Camilo A. A1 - Ordonez, Alvaro A. A1 - Takase, Kei A1 - Lapa, Constantin A1 - Jain, Sanjay K. A1 - Pomper, Martin G. A1 - Rowe, Steven P. A1 - Higuchi, Takahiro T1 - Current and future perspectives on functional molecular imaging in nephro-urology: theranostics on the horizon JF - Theranostics N2 - In recent years, a paradigm shift from single-photon-emitting radionuclide radiotracers toward positron-emission tomography (PET) radiotracers has occurred in nuclear oncology. Although PET-based molecular imaging of the kidneys is still in its infancy, such a trend has emerged in the field of functional renal radionuclide imaging. Potentially allowing for precise and thorough evaluation of renal radiotracer urodynamics, PET radionuclide imaging has numerous advantages including precise anatomical co-registration with CT images and dynamic three-dimensional imaging capability. In addition, relative to scintigraphic approaches, PET can allow for significantly reduced scan time enabling high-throughput in a busy PET practice and further reduces radiation exposure, which may have a clinical impact in pediatric populations. In recent years, multiple renal PET radiotracers labeled with C-11, Ga-68, and F-18 have been utilized in clinical studies. Beyond providing a precise non-invasive read-out of renal function, such radiotracers may also be used to assess renal inflammation. This manuscript will provide an overview of renal molecular PET imaging and will highlight the transformation of conventional scintigraphy of the kidneys toward novel, high-resolution PET imaging for assessing renal function. In addition, future applications will be introduced, e.g. by transferring the concept of molecular image-guided diagnostics and therapy (theranostics) to the field of nephrology. KW - glomerular filtration rate KW - renal KW - kidney KW - renal function KW - positron emission tomography KW - nephrology KW - urology KW - molecular imaging KW - theranostics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260090 VL - 11 IS - 12 ER - TY - INPR A1 - Werner, Rudolf A. A1 - Andree, Christian A1 - Javadi, Mehrbod S. A1 - Lapa, Constantin A1 - Buck, Andreas K. A1 - Higuchi, Takahiro A1 - Pomper, Martin G. A1 - Gorin, Michael A. A1 - Rowe, Steven P. A1 - Pienta, Kenneth J. T1 - A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging T2 - Urology - The Gold Journal N2 - No abstract available. KW - 18F-DCFPyL KW - Virchow Node KW - PSMA-PET KW - Virchow Node KW - Positron Emission Tomography KW - Prostate Cancer KW - PET Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161103 SN - 0090-4295 N1 - This is the accepted manuscript of Rudolf Werner, Christian Andree, Mehrbod S. Javadi, Constantin Lapa, Andreas K. Buck, Takahiro Higuchi, Martin G. Pomper, Michael A.Gorin, Steven P.Rowe, Kenneth J. Pienta: A Voice From the Past: Re-Discovering the Virchow Node with PSMA-Targeted 18F-DCFPyL PET Imaging. Published in Urology 117(2018), p. 18-21. https://doi.org/10.1016/j.urology.2018.03.030 N1 - Die finale Version dieses Artikels steht unter https://doi.org/10.1016/j.urology.2018.03.030 oder https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-164632 open access zur Verfügung. ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Andree, Christian A1 - Javadi, Mehrbod S. A1 - Lapa, Constantin A1 - Buck, Andreas K. A1 - Higuchi, Takahiro A1 - Pomper, Martin G. A1 - Gorin, Michael A. A1 - Rowe, Steven P. A1 - Pienta, Kenneth J. T1 - A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging JF - Urology - The Gold Journal N2 - No abstract available. KW - 18F-DCFPyL KW - PET KW - PSMA-PET KW - Positron Emission Tomography KW - Prostate Cancer KW - Virchow Node Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164632 SN - 0090-4295 VL - 117 ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Derlin, Thorsten A1 - Lapa, Constantin A1 - Sheikbahaei, Sara A1 - Higuchi, Takahiro A1 - Giesel, Frederik L. A1 - Behr, Spencer A1 - Drzezga, Alexander A1 - Kimura, Hiroyuki A1 - Buck, Andreas K. A1 - Bengel, Frank M. A1 - Pomper, Martin G. A1 - Gorin, Michael A. A1 - Rowe, Steven P. T1 - \(^{18}\)F-labeled, PSMA-targeted radiotracers: leveraging the advantages of radiofluorination for prostate cancer molecular imaging JF - Theranostics N2 - Prostate-specific membrane antigen (PSMA)-targeted PET imaging for prostate cancer with \(^{68}\)Ga-labeled compounds has rapidly become adopted as part of routine clinical care in many parts of the world. However, recent years have witnessed the start of a shift from \(^{68}\)Ga- to \(^{18}\)F-labeled PSMA-targeted compounds. The latter imaging agents have several key advantages, which may lay the groundwork for an even more widespread adoption into the clinic. First, facilitated delivery from distant suppliers expands the availability of PET radiopharmaceuticals in smaller hospitals operating a PET center but lacking the patient volume to justify an onsite \(^{68}\)Ge/\(^{68}\)Ga generator. Thus, such an approach meets the increasing demand for PSMA-targeted PET imaging in areas with lower population density and may even lead to cost-savings compared to in-house production. Moreover, \(^{18}\)F-labeled radiotracers have a higher positron yield and lower positron energy, which in turn decreases image noise, improves contrast resolution, and maximizes the likelihood of detecting subtle lesions. In addition, the longer half-life of 110 min allows for improved delayed imaging protocols and flexibility in study design, which may further increase diagnostic accuracy. Moreover, such compounds can be distributed to sites which are not allowed to produce radiotracers on-site due to regulatory issues or to centers without access to a cyclotron. In light of these advantageous characteristics, \(^{18}\)F-labeled PSMA-targeted PET radiotracers may play an important role in both optimizing this transformative imaging modality and making it widely available. We have aimed to provide a concise overview of emerging \(^{18}\)F-labeled PSMA-targeted radiotracers undergoing active clinical development. Given the wide array of available radiotracers, comparative studies are needed to firmly establish the role of the available \(^{18}\)F-labeled compounds in the field of molecular PCa imaging, preferably in different clinical scenarios. KW - Radiofluorine KW - prostate-specific membrane antigen KW - prostate cancer KW - \(^{18}\)F KW - PSMA KW - \(^{68}\)Ga KW - theranostics KW - radioligand therapy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202559 SN - 1838-7640 VL - 10 IS - 1 ER - TY - JOUR A1 - Breun, Maria A1 - Monoranu, Camelia M. A1 - Kessler, Almuth F. A1 - Matthies, Cordula A1 - Löhr, Mario A1 - Hagemann, Carsten A1 - Schirbel, Andreas A1 - Rowe, Steven P. A1 - Pomper, Martin G. A1 - Buck, Andreas K. A1 - Wester, Hans-Jürgen A1 - Ernestus, Ralf-Ingo A1 - Lapa, Constantin T1 - [\(^{68}\)Ga]-Pentixafor PET/CT for CXCR4-mediated imaging of vestibular schwannomas JF - Frontiers in Oncology N2 - We have recently demonstrated CXCR4 overexpression in vestibular schwannomas (VS). This study investigated the feasibility of CXCR4-directed positron emission tomography/computed tomography (PET/CT) imaging of VS using the radiolabeled chemokine ligand [\(^{68}\)Ga]Pentixafor. Methods: 4 patients with 6 primarily diagnosed or pre-treated/observed VS were enrolled. All subjects underwent [\(^{68}\)Ga]Pentixafor PET/CT prior to surgical resection. Images were analyzed visually and semi-quantitatively for CXCR4 expression including calculation of tumor-to-background ratios (TBR). Immunohistochemistry served as standard of reference in three patients. Results: [\(^{68}\)Ga]Pentixafor PET/CT was visually positive in all cases. SUV\(_{mean}\) and SUV\(_{max}\) were 3.0 ± 0.3 and 3.8 ± 0.4 and TBR\(_{mean}\) and TBR\(_{max}\) were 4.0 ± 1.4 and 5.0 ± 1.7, respectively. Histological analysis confirmed CXCR4 expression in tumors. Conclusion: Non-invasive imaging of CXCR4 expression using [\(^{68}\)Ga]Pentixafor PET/CT of VS is feasible and could prove useful for in vivo assessment of CXCR4 expression. KW - vestibular schwannoma KW - CXCR4 KW - PET/CT KW - molecular imaging KW - Pentixafor Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201863 VL - 9 IS - 503 ER -