@article{LapaHerrmannSchirbeletal.2017,
  author    = {Lapa, Constantin and Herrmann, Ken and Schirbel, Andreas and H{\"a}nscheid, Heribert and L{\"u}ckerath, Katharina and Schottelius, Margret and Kircher, Malte and Werner, Rudolf A. and Schreder, Martin and Samnick, Samuel and Kropf, Saskia and Knop, Stefan and Buck, Andreas K. and Einsele, Hermann and Wester, Hans-Juergen and Kort{\"u}m, K. Martin},
  title     = {CXCR4-directed endoradiotherapy induces high response rates in extramedullary relapsed multiple myeloma},
  series = {Theranostics},
  volume    = {7},
  journal   = {Theranostics},
  number    = {6},
  doi       = {10.7150/thno.19050},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172095},
  pages     = {1589-1597},
  year      = {2017},
  abstract  = {C-X-C-motif chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. We have recently reported promising first-in-man experience with CXCR4-directed endoradiotherapy (ERT) in multiple myeloma (MM). Eight heavily pretreated MM patients underwent a total of 10 ERT cycles (7 patients with 1 cycle and a single patient with 3 cycles). ERT was administered in combination with chemotherapy and autologous stem cell support. End points were occurrence and timing of adverse events, progression-free and overall survival. ERT was overall well tolerated without any unexpected acute adverse events or changes in vital signs. With absorbed tumor doses >30-70 Gy in intra- or extramedullary lesions, significant anti-myeloma activity was observed with 1 patient achieving complete remission and 5/8 partial remission. Directly after ERT major infectious complications were seen in one patient who died from sepsis 22 days after ERT, another patient with high tumor burden experienced lethal tumor lysis syndrome. Median progression-free survival was 54 days (range, 13-175), median overall survival was 223 days (range, 13-313). During follow-up (6 patients available), one patient died from infectious complications, 2/8 from disease progression, the remaining 3/8 patients are still alive. CXCR4-directed ERT was well-tolerated and exerted anti-myeloma activity even at very advanced stage MM with presence of extramedullary disease. Further assessment of this novel treatment option is highly warranted.},
  language  = {en}
}
@article{WernerKircherHiguchietal.2019,
  author    = {Werner, Rudolf A. and Kircher, Stefan and Higuchi, Takahiro and Kircher, Malte and Schirbel, Andreas and Wester, Hans-J{\"u}rgen and Buck, Andreas K. and Pomper, Martin G. and Rowe, Steven P. and Lapa, Constantin},
  title     = {CXCR4-directed imaging in solid tumors},
  series = {Frontiers in Oncology},
  volume    = {9},
  journal   = {Frontiers in Oncology},
  number    = {770},
  issn      = {2234-943X},
  doi       = {10.3389/fonc.2019.00770},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195678},
  year      = {2019},
  abstract  = {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-na{\"i}ve 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-na{\"i}ve 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.},
  language  = {en}
}
@article{WeichWernerBucketal.2021,
  author    = {Weich, Alexander and Werner, Rudolf A. and Buck, Andreas K. and Hartrampf, Philipp E. and Serfling, Sebastian E. and Scheurlen, Michael and Wester, Hans-J{\"u}rgen and Meining, Alexander and Kircher, Stefan and Higuchi, Takahiro and Pomper, Martin G. and Rowe, Steven P. and Lapa, Constantin and Kircher, Malte},
  title     = {CXCR4-Directed PET/CT in Patients with Newly Diagnosed Neuroendocrine Carcinomas},
  series = {Diagnostics},
  volume    = {11},
  journal   = {Diagnostics},
  number    = {4},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics11040605},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234231},
  year      = {2021},
  abstract  = {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-na{\"i}ve 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.},
  language  = {en}
}
@article{LambertiniHartrampfHiguchietal.2022,
  author    = {Lambertini, Alessandro and Hartrampf, Philipp E. and Higuchi, Takahiro and Serfling, Sebastian E. and Meybohm, Patrick and Schirbel, Andreas and Buck, Andreas K. and Werner, Rudolf A.},
  title     = {CXCR4-targeted molecular imaging after severe SARS-Cov-2 infection},
  series = {European Journal of Nuclear Medicine and Molecular Imaging},
  volume    = {50},
  journal   = {European Journal of Nuclear Medicine and Molecular Imaging},
  number    = {1},
  doi       = {10.1007/s00259-022-05932-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324619},
  pages     = {228-229},
  year      = {2022},
  abstract  = {No abstract available.},
  language  = {en}
}
@article{BuckSerflingLindneretal.2022,
  author    = {Buck, Andreas K. and Serfling, Sebastian E. and Lindner, Thomas and H{\"a}nscheid, Heribert and Schirbel, Andreas and Hahner, Stefanie and Fassnacht, Martin and Einsele, Hermann and Werner, Rudolf A.},
  title     = {CXCR4-targeted theranostics in oncology},
  series = {European Journal of Nuclear Medicine and Molecular Imaging},
  volume    = {49},
  journal   = {European Journal of Nuclear Medicine and Molecular Imaging},
  number    = {12},
  doi       = {10.1007/s00259-022-05849-y},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324545},
  pages     = {4133-4144},
  year      = {2022},
  abstract  = {A growing body of literature reports on the upregulation of C-X-C motif chemokine receptor 4 (CXCR4) in a variety of cancer entities, rendering this receptor as suitable target for molecular imaging and endoradiotherapy in a theranostic setting. For instance, the CXCR4-targeting positron emission tomography (PET) agent [\(^{68}\)Ga]PentixaFor has been proven useful for a comprehensive assessment of the current status quo of solid tumors, including adrenocortical carcinoma or small-cell lung cancer. In addition, [\(^{68}\)Ga]PentixaFor has also provided an excellent readout for hematological malignancies, such as multiple myeloma, marginal zone lymphoma, or mantle cell lymphoma. PET-based quantification of the CXCR4 capacities in vivo allows for selecting candidates that would be suitable for treatment using the theranostic equivalent [\(^{177}\)Lu]/[\(^{90}\)Y]PentixaTher. This CXCR4-directed theranostic concept has been used as a conditioning regimen prior to hematopoietic stem cell transplantation and to achieve sufficient anti-lymphoma/-tumor activity in particular for malignant tissues that are highly sensitive to radiation, such as the hematological system. Increasing the safety margin, pretherapeutic dosimetry is routinely performed to determine the optimal activity to enhance therapeutic efficacy and to reduce off-target adverse events. The present review will provide an overview of current applications for CXCR4-directed molecular imaging and will introduce the CXCR4-targeted theranostic concept for advanced hematological malignancies.},
  language  = {en}
}
@article{HartrampfLapaSerflingetal.2021,
  author    = {Hartrampf, Philipp E. and Lapa, Constantin and Serfling, Sebastian E. and Buck, Andreas K. and Seitz, Anna Katharina and Meyer, Philipp T. and Ruf, Juri and Michalski, Kerstin},
  title     = {Development of Discordant Hypermetabolic Prostate Cancer Lesions in the Course of [\(^{177}\)Lu]PSMA Radioligand Therapy and Their Possible Influence on Patient Outcome},
  series = {Cancers},
  volume    = {13},
  journal   = {Cancers},
  number    = {17},
  issn      = {2072-6694},
  doi       = {10.3390/cancers13174270},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245168},
  year      = {2021},
  abstract  = {Simple Summary Discordant FDG-positive but PSMA-negative (FDG+/PSMA-) metastases constitute a negative prognostic marker of overall survival in patients undergoing PSMA radioligand therapy (RLT). The aim of this analysis was to investigate the prognostic implications of new FDG+/PSMA- lesions, which occur during or after PSMA RLT. In a retrospective bicentric analysis of 32 patients undergoing PSMA RLT and follow-up dual tracer staging with PSMA and FDG PET/CT, FDG+/PSMA- lesions occurred in a limited number of patients. However, the presence of FDG+/PSMA- lesions appears not to have a significant impact on the OS, but further studies are needed to establish the clinical relevance of such lesions. Abstract Introduction: Positron emission tomography/computer tomography (PET/CT) targeting the prostate-specific membrane antigen (PSMA) is crucial for the assessment of adequate PSMA expression in patients with metastatic castration-resistant prostate cancer (mCRPC) prior to PSMA radioligand therapy (PSMA RLT). Moreover, initial dual tracer staging using combined PSMA and [\(^{18}\)F]fluorodeoxyglucose (FDG) PET/CT provides relevant information, since discordant FDG-positive but PSMA-negative (FDG+/PSMA-) lesions constitute a negative prognostic marker of overall survival (OS) after PSMA RLT. However, little is known about the prognostic implications of dual tracer imaging for restaging at follow-up. The aim of this analysis was to investigate the prognostic implications of new FDG+/PSMA- lesions during or after PSMA RLT. Methods: This bicentric analysis included 32 patients with mCRPC who underwent both FDG and PSMA PET/CT imaging after two or four cycles of PSMA RLT. Patients with FDG+/PSMA- lesions prior to PSMA RLT were not considered. The presence of FDG+/PSMA- lesions was assessed with follow-up dual tracer imaging of patients after two or four cycles of PSMA RLT. Patients with at least one new FDG+/PSMA- lesion were compared to patients without any FDG+/PSMA- lesions at the respective time points. A log-rank analysis was used to assess the difference in OS between subgroups. Results: After two cycles of PSMA RLT, four of 32 patients (13\%) had FDG+/PSMA- metastases. No significant difference in OS was observed (p = 0.807), as compared to patients without FDG+/PSMA- lesions. Follow-up dual tracer imaging after the 4th cycle of PSMA RLT was available in 18 patients. Of these, four patients presented with FDG+/PSMA- findings (n = 2 already after two cycles). After the fourth cycle of PSMA RLT, no significant difference in OS was observed between patients with and without FDG+/PSMA- lesions (p = 0.442). Conclusion: This study shows that FDG+/PSMA- lesions develop in a limited number of patients undergoing PSMA RLT. Further studies are needed to establish the clinical relevance of such lesions.},
  language  = {en}
}
@inproceedings{WernerMarcusSheikhbahaeietal.2018,
  author    = {Werner, Rudolf A. and Marcus, Charles and Sheikhbahaei, Sara and Higuchi, Takahiro and Solnes, Lilja B. and Rowe, Steven P. and Buck, Andreas K. and Lapa, Constantin and Javadi, Mehrbod S.},
  title     = {Diagnostic Accuracy of Visual Assessment of an Initial DaT-Scan in Comparison to a Fully Automatic Semiquantitative Method},
  series = {Journal of Nuclear Medicine},
  volume    = {59},
  booktitle = {Journal of Nuclear Medicine},
  number    = {Supplement No. 1},
  issn      = {0161-5505},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162208},
  pages     = {626},
  year      = {2018},
  abstract  = {No abstract available.},
  subject      = {Parkinson-Krankheit},
  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{IsraelRiehlButtetal.2023,
  author    = {Israel, Ina and Riehl, Gabriele and Butt, Elke and Buck, Andreas K. and Samnick, Samuel},
  title     = {Gallium-68-labeled KISS1-54 peptide for mapping KISS1 receptor via PET: initial evaluation in human tumor cell lines and in tumor-bearing mice},
  series = {Pharmaceuticals},
  volume    = {17},
  journal   = {Pharmaceuticals},
  number    = {1},
  issn      = {1424-8247},
  doi       = {10.3390/ph17010044},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-355898},
  year      = {2023},
  abstract  = {Kisspeptins (KPs, KISS1) and their receptor (KISS1R) play a pivotal role as metastasis suppressor for many cancers. Low or lost KP expression is associated with higher tumor grade, increased metastatic potential, and poor prognosis. Therefore, KP expression has prognostic relevance and correlates with invasiveness in cancers. Furthermore, KISS1R represents a very promising target for molecular imaging and therapy for KISS1R-expressing tumors. The goal of this study was to evaluate the developed KISS1-54 derivative, [\(^{68}\)Ga]KISS1-54, as a PET-imaging probe for KISS1R-expressing tumors. The NODAGA-KISS1-54 peptide was labeled by Gallium-68, and the stability of the resulting [\(^{68}\)Ga]KISS1-54 evaluated in injection solution and human serum, followed by an examination in different KISS1R-expressing tumor cell lines, including HepG2, HeLa, MDA-MB-231, MCF7, LNCap, SK-BR-3, and HCT116. Finally, [\(^{68}\)Ga]KISS1-54 was tested in LNCap- and MDA-MB-231-bearing mice, using µ-PET, assessing its potential as an imaging probe for PET. [\(^{68}\)Ga]KISS1-54 was obtained in a 77 ± 7\% radiochemical yield and at a >99\% purity. The [\(^{68}\)Ga]KISS1-54 cell uptake amounted to 0.6-4.4\% per 100,000 cells. Moreover, the accumulation of [\(^{68}\)Ga]KISS1-54 was effectively inhibited by nonradioactive KISS1-54. In [\(^{68}\)Ga]KISS1-54-PET, KISS1R-positive LNCap-tumors were clearly visualized as compared to MDA-MB-231-tumor implant with predominantly intracellular KISS1R expression. Our first results suggest that [\(^{68}\)Ga]KISS1-54 is a promising candidate for a radiotracer for targeting KISS1R-expressing tumors via PET.},
  language  = {en}
}
@article{HartrampfWeinzierlSerflingetal.2022,
  author    = {Hartrampf, Philipp E. and Weinzierl, Franz-Xaver and Serfling, Sebastian E. and Pomper, Martin G. and Rowe, Steven P. and Higuchi, Takahiro and Seitz, Anna Katharina and K{\"u}bler, Hubert and Buck, Andreas K. and Werner, Rudolf A.},
  title     = {Hematotoxicity and nephrotoxicity in prostate cancer patients undergoing radioligand therapy with [\(^{177}\)Lu]Lu-PSMA I\&T},
  series = {Cancers},
  volume    = {14},
  journal   = {Cancers},
  number    = {3},
  issn      = {2072-6694},
  doi       = {10.3390/cancers14030647},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254825},
  year      = {2022},
  abstract  = {(1) Background: Prostate-specific membrane antigen (PSMA)-directed radioligand therapy (RLT) has shown remarkable results in patients with advanced prostate cancer. We aimed to evaluate the toxicity profile of the PSMA ligand [\(^{177}\)Lu]Lu-PSMA I\&T. (2) Methods: 49 patients with metastatic, castration-resistant prostate cancer treated with at least three cycles of [\(^{177}\)Lu]Lu-PSMA I\&T were evaluated. Prior to and after RLT, we compared leukocytes, hemoglobin, platelet counts, and renal functional parameters (creatinine, eGFR, n = 49; [\(^{99m}\)Tc]-MAG3-derived tubular extraction rate (TER), n = 42). Adverse events were classified according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 and KDIGO Society. To identify predictive factors, we used Spearman's rank correlation coefficient. (3) Results: A substantial fraction of the patients already showed impaired renal function and reduced leukocyte counts at baseline. Under RLT, 11/49 (22\%) patients presented with nephrotoxicity CTCAE I or II according to creatinine, but 33/49 (67\%) according to eGFR. Only 5/42 (13\%) showed reduced TER, defined as <70\% of the age-adjusted mean normal values. Of all renal functional parameters, absolute changes of only 2\% were recorded. CTCAE-based re-categorization was infrequent, with creatinine worsening from I to II in 2/49 (4.1\%; GFR, 1/49 (2\%)). Similar results were recorded for KDIGO (G2 to G3a, 1/49 (2\%); G3a to G3b, 2/49 (4.1\%)). After three cycles, follow-up eGFR correlated negatively with age (r = -0.40, p = 0.005) and the eGFR change with Gleason score (r = -0.35, p < 0.05) at baseline. Leukocytopenia CTCAE II occurred only in 1/49 (2\%) (CTCAE I, 20/49 (41\%)) and CTCAE I thrombocytopenia in 7/49 (14\%), with an absolute decrease of 15.2\% and 16.6\% for leukocyte and platelet counts. Anemia CTCAE II occurred in 10/49 (20\%) (CTCAE I, 36/49 (73\%)) with a decrease in hemoglobin of 4.7\%. (4) Conclusions: After PSMA-targeted therapy using [\(^{177}\)Lu]Lu-PSMA I\&T, no severe (CTCAE III/IV) toxicities occurred, thereby demonstrating that serious adverse renal or hematological events are unlikely to be a frequent phenomenon with this agent.},
  language  = {en}
}