@article{WernerSayehliHaenscheidetal.2023,
  author    = {Werner, Rudolf A. and Sayehli, Cyrus and H{\"a}nscheid, Heribert and Higuchi, Takahiro and Serfling, Sebastian E. and Fassnacht, Martin and Goebeler, Maria-Elisabeth and Buck, Andreas K. and Kroiss, Matthias},
  title     = {Successful combination of selpercatinib and radioiodine after pretherapeutic dose estimation in RET-altered thyroid carcinoma},
  series = {European Journal of Nuclear Medicine and Molecular Imaging},
  volume    = {50},
  journal   = {European Journal of Nuclear Medicine and Molecular Imaging},
  number    = {6},
  doi       = {10.1007/s00259-022-06061-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324435},
  pages     = {1833-1834},
  year      = {2023},
  abstract  = {No abstract available.},
  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{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}
}
@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}
}
@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{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{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}
}
@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{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}
}
@article{SerflingLapaDreheretal.2022,
  author    = {Serfling, Sebastian E. and Lapa, Constantin and Dreher, Niklas and Hartrampf, Philipp E. and Rowe, Steven P. and Higuchi, Takahiro and Schirbel, Andreas and Weich, Alexander and Hahner, Stefanie and Fassnacht, Martin and Buck, Andreas K. and Werner, Rudolf A.},
  title     = {Impact of tumor burden on normal organ distribution in patients imaged with CXCR4-targeted [\(^{68}\)Ga]Ga-PentixaFor PET/CT},
  series = {Molecular Imaging and Biology},
  volume    = {24},
  journal   = {Molecular Imaging and Biology},
  number    = {4},
  doi       = {10.1007/s11307-022-01717-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324622},
  pages     = {659-665},
  year      = {2022},
  abstract  = {Background CXCR4-directed positron emission tomography/computed tomography (PET/CT) has been used as a diagnostic tool in patients with solid tumors. We aimed to determine a potential correlation between tumor burden and radiotracer accumulation in normal organs. Methods Ninety patients with histologically proven solid cancers underwent CXCR4-targeted [\(^{68}\)Ga]Ga-PentixaFor PET/CT. Volumes of interest (VOIs) were placed in normal organs (heart, liver, spleen, bone marrow, and kidneys) and tumor lesions. Mean standardized uptake values (SUV\(_{mean}\)) for normal organs were determined. For CXCR4-positive tumor burden, maximum SUV (SUV\(_{max}\)), tumor volume (TV), and fractional tumor activity (FTA, defined as SUV\(_{mean}\) x TV), were calculated. We used a Spearman's rank correlation coefficient (ρ) to derive correlative indices between normal organ uptake and tumor burden. Results Median SUV\(_{mean}\) in unaffected organs was 5.2 for the spleen (range, 2.44 - 10.55), 3.27 for the kidneys (range, 1.52 - 17.4), followed by bone marrow (1.76, range, 0.84 - 3.98), heart (1.66, range, 0.88 - 2.89), and liver (1.28, range, 0.73 - 2.45). No significant correlation between SUV\(_{max}\) in tumor lesions (ρ ≤ 0.189, P ≥ 0.07), TV (ρ ≥ -0.204, P ≥ 0.06) or FTA (ρ ≥ -0.142, P ≥ 0.18) with the investigated organs was found. Conclusions In patients with solid tumors imaged with [\(^{68}\)Ga]Ga-PentixaFor PET/CT, no relevant tumor sink effect was noted. This observation may be of relevance for therapies with radioactive and non-radioactive CXCR4-directed drugs, as with increasing tumor burden, the dose to normal organs may remain unchanged.},
  language  = {en}
}