@article{HartrampfHeinrichSeitzetal.2020, author = {Hartrampf, Philipp E. and Heinrich, Marieke and Seitz, Anna Katharina and Brumberg, Joachim and Sokolakis, Ioannis and Kalogirou, Charis and Schirbel, Andreas and K{\"u}bler, Hubert and Buck, Andreas K. and Lapa, Constantin and Krebs, Markus}, title = {Metabolic Tumour Volume from PSMA PET/CT Scans of Prostate Cancer Patients during Chemotherapy — Do Different Software Solutions Deliver Comparable Results?}, series = {Journal of Clinical Medicine}, volume = {9}, journal = {Journal of Clinical Medicine}, number = {5}, issn = {2077-0383}, doi = {10.3390/jcm9051390}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-205893}, year = {2020}, abstract = {(1) Background: Prostate-specific membrane antigen (PSMA)-derived tumour volume (PSMA-TV) and total lesion PSMA (TL-PSMA) from PSMA PET/CT scans are promising biomarkers for assessing treatment response in prostate cancer (PCa). Currently, it is unclear whether different software tools for assessing PSMA-TV and TL-PSMA produce comparable results. (2) Methods: \(^{68}\)Ga-PSMA PET/CT scans from n = 21 patients with castration-resistant PCa (CRPC) receiving chemotherapy were identified from our single-centre database. PSMA-TV and TL-PSMA were calculated with Syngo.via (Siemens) as well as the freely available Beth Israel plugin for FIJI (Fiji Is Just ImageJ) before and after chemotherapy. While statistical comparability was illustrated and quantified via Bland-Altman diagrams, the clinical agreement was estimated by matching PSMA-TV, TL-PSMA and relative changes of both variables during chemotherapy with changes in serum PSA (ΔPSA) and PERCIST (Positron Emission Response Criteria in Solid Tumors). (3) Results: Comparing absolute PSMA-TV and TL-PSMA as well as Bland-Altman plotting revealed a good statistical comparability of both software algorithms. For clinical agreement, classifying therapy response did not differ between PSMA-TV and TL-PSMA for both software solutions and showed highly positive correlations with BR. (4) Conclusions: due to the high levels of statistical and clinical agreement in our CRPC patient cohort undergoing taxane chemotherapy, comparing PSMA-TV and TL-PSMA determined by Syngo.via and FIJI appears feasible.}, language = {en} } @article{HartrampfBundschuhWeinzierletal.2022, author = {Hartrampf, Philipp E. and Bundschuh, Ralph A. and Weinzierl, Franz-Xaver and Serfling, Sebastian E. and Kosmala, Aleksander and Seitz, Anna Katharina and K{\"u}bler, Hubert and Buck, Andreas K. and Essler, Markus and Werner, Rudolf A.}, title = {mCRPC patients with PSA fluctuations under radioligand therapy have comparable survival benefits relative to patients with sustained PSA decrease}, series = {European Journal of Nuclear Medicine and Molecular Imaging}, volume = {49}, journal = {European Journal of Nuclear Medicine and Molecular Imaging}, number = {13}, doi = {10.1007/s00259-022-05910-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324562}, pages = {4727-4735}, year = {2022}, abstract = {Introduction In men with metastatic castration-resistant prostate cancer (mCRPC) scheduled for prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT), biochemical response is assessed based on repeated measurements of prostate-specific antigen (PSA) levels. We aimed to determine overall survival (OS) in patients experiencing sustained PSA increase, decrease, or fluctuations during therapy. Materials and methods In this bicentric study, we included 176 mCRPC patients treated with PSMA-directed RLT. PSA levels were determined using blood samples prior to the first RLT and on the admission days for the following cycles. We calculated relative changes in PSA levels compared to baseline. Kaplan-Meier curves as well as log-rank test were used to compare OS of different subgroups, including patients with sustained PSA increase, decrease, or fluctuations (defined as change after initial decrease or increase after the first cycle). Results Sixty-one out of one hundred seventy-six (34.7\%) patients showed a sustained increase and 86/176 (48.8\%) a sustained decrease in PSA levels. PSA fluctuations were observed in the remaining 29/176 (16.5\%). In this subgroup, 22/29 experienced initial PSA decrease followed by an increase (7/29, initial increase followed by a decrease). Median OS of patients with sustained decrease in PSA levels was significantly longer when compared to patients with sustained increase of PSA levels (19 vs. 8 months; HR 0.35, 95\% CI 0.22-0.56; P < 0.001). Patients with PSA fluctuations showed a significantly longer median OS compared to patients with sustained increase of PSA levels (18 vs. 8 months; HR 0.49, 95\% CI 0.30-0.80; P < 0.01), but no significant difference relative to men with sustained PSA decrease (18 vs. 19 months; HR 1.4, 95\% CI 0.78-2.49; P = 0.20). In addition, in men experiencing PSA fluctuations, median OS did not differ significantly between patients with initial decrease or initial increase of tumor marker levels (16 vs. 18 months; HR 1.2, 95\% CI 0.38-4.05; P = 0.68). Conclusion Initial increase or decrease of PSA levels is sustained in the majority of patients undergoing RLT. Sustained PSA decrease was linked to prolonged survival and men with PSA fluctuations under treatment experienced comparable survival benefits. As such, transient tumor marker oscillations under RLT should rather not lead to treatment discontinuation, especially in the absence of radiological progression.}, language = {en} } @article{GoeringSchumannMuelleretal.2022, author = {G{\"o}ring, Lukas and Schumann, Sarah and M{\"u}ller, Jessica and Buck, Andreas K. and Port, Matthias and Lassmann, Michael and Scherthan, Harry and Eberlein, Uta}, title = {Repair of a-particle-induced DNA damage in peripheral blood mononuclear cells after internal ex vivo irradiation with \(^{223}\)Ra}, 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/s00259-022-05860-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324557}, pages = {3981-3988}, year = {2022}, abstract = {Purpose As α-emitters for radiopharmaceutical therapies are administered systemically by intravenous injection, blood will be irradiated by α-particles that induce clustered DNA double-strand breaks (DSBs). Here, we investigated the induction and repair of DSB damage in peripheral blood mononuclear cells (PBMCs) as a function of the absorbed dose to the blood following internal ex vivo irradiation with [\(^{223}\)Ra]RaCl2. Methods Blood samples of ten volunteers were irradiated by adding [\(^{223}\)Ra]RaCl2 solution with different activity concentrations resulting in absorbed doses to the blood of 3 mGy, 25 mGy, 50 mGy and 100 mGy. PBMCs were isolated, divided in three parts and either fixed directly (d-samples) or after 4 h or 24 h culture. After immunostaining, the induced γ-H2AX α-tracks were counted. The time-dependent decrease in α-track frequency was described with a model assuming a repair rate R and a fraction of non-repairable damage Q. Results For 25 mGy, 50 mGy and 100 mGy, the numbers of α-tracks were significantly increased compared to baseline at all time points. Compared to the corresponding d-samples, the α-track frequency decreased significantly after 4 h and after 24 h. The repair rates R were (0.24 ± 0.05) h-1 for 25 mGy, (0.16 ± 0.04) h-1 for 50 mGy and (0.13 ± 0.02) h-1 for 100 mGy, suggesting faster repair at lower absorbed doses, while Q-values were similar. Conclusion The results obtained suggest that induction and repair of the DSB damage depend on the absorbed dose to the blood. Repair rates were similar to what has been observed for irradiation with low linear energy transfer.}, language = {en} } @article{GrafLiHerrmannetal.2014, author = {Graf, Nicolas and Li, Zhoulei and Herrmann, Ken and Weh, Daniel and Aichler, Michaela and Slawska, Jolanta and Walch, Axel and Peschel, Christian and Schwaiger, Markus and Buck, Andreas K. and Dechow, Tobias and Keller, Ulrich}, title = {Positron emission tomographic monitoring of dual phosphatidylinositol-3-kinase and mTOR inhibition in anaplastic large cell lymphoma}, series = {Oncotargets and Therapy}, volume = {7}, journal = {Oncotargets and Therapy}, doi = {10.2147/OTT.S59314}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117915}, pages = {789-798}, year = {2014}, abstract = {Background: Dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibition offers an attractive therapeutic strategy in anaplastic large cell lymphoma depending on oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) signaling. We tested the efficacy of a novel dual PI3K/mTOR inhibitor, NVP-BGT226 (BGT226), in two anaplastic large cell lymphoma cell lines in vitro and in vivo and performed an early response evaluation with positron emission tomography (PET) imaging using the standard tracer, 2-deoxy-2-[F-18] fluoro-D-glucose (FDG) and the thymidine analog, 3'-deoxy-3'-[F-18] fluorothymidine (FLT). Methods: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling. FDG-PET and FLT-PET were performed in immunodeficient mice bearing either SU-DHL-1 or Karpas299 xenografts at baseline and 7 days after initiation of treatment with BGT226. Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects. Results: SU-DHL-1 cells showed sensitivity to BGT226 in vitro, with cell cycle arrest in G0/G1 phase and an IC50 in the low nanomolar range, in contrast with Karpas299 cells, which were mainly resistant to BGT226. In vivo, both FDG-PET and FLT-PET discriminated sensitive from resistant lymphoma, as indicated by a significant reduction of tumor-to-background ratios on day 7 in treated SU-DHL-1 lymphoma-bearing animals compared with the control group, but not in animals with Karpas299 xenografts. Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue. Conclusion: Dual PI3K/mTOR inhibition using BGT226 is effective in ALK-positive anaplastic large cell lymphoma and can be monitored with both FDG-PET and FLT-PET early on in the course of therapy.}, language = {en} } @article{FroehlichSerflingHiguchietal.2021, author = {Fr{\"o}hlich, Matthias and Serfling, Sebastian and Higuchi, Takahiro and Pomper, Martin G. and Rowe, Steven P. and Schmalzing, Marc and Tony, Hans-Peter and Gernert, Michael and Strunz, Patrick-Pascal and Portegys, Jan and Schwaneck, Eva-Christina and Gadeholt, Ottar and Weich, Alexander and Buck, Andreas K. and Bley, Thorsten A. and Guggenberger, Konstanze V. and Werner, Rudolf A.}, title = {Whole-Body [\(^{18}\)F]FDG PET/CT Can Alter Diagnosis in Patients with Suspected Rheumatic Disease}, series = {Diagnostics}, volume = {11}, journal = {Diagnostics}, number = {11}, issn = {2075-4418}, doi = {10.3390/diagnostics11112073}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250227}, year = {2021}, abstract = {The 2-deoxy-d-[\(^{18}\)F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) is widely utilized to assess the vascular and articular inflammatory burden of patients with a suspected diagnosis of rheumatic disease. We aimed to elucidate the impact of [\(^{18}\)F]FDG PET/CT on change in initially suspected diagnosis in patients at the time of the scan. Thirty-four patients, who had undergone [\(^{18}\)F]FDG PET/CT, were enrolled and the initially suspected diagnosis prior to [18F]FDG PET/CT was compared to the final diagnosis. In addition, a semi-quantitative analysis including vessel wall-to-liver (VLR) and joint-to-liver (JLR) ratios was also conducted. Prior to [\(^{18}\)F]FDG PET/CT, 22/34 (64.7\%) of patients did not have an established diagnosis, whereas in 7/34 (20.6\%), polymyalgia rheumatica (PMR) was suspected, and in 5/34 (14.7\%), giant cell arteritis (GCA) was suspected by the referring rheumatologists. After [\(^{18}\)F]FDG PET/CT, the diagnosis was GCA in 19/34 (55.9\%), combined GCA and PMR (GCA + PMR) in 9/34 (26.5\%) and PMR in the remaining 6/34 (17.6\%). As such, [\(^{18}\)F]FDG PET/CT altered suspected diagnosis in 28/34 (82.4\%), including in all unclear cases. VLR of patients whose final diagnosis was GCA tended to be significantly higher when compared to VLR in PMR (GCA, 1.01 ± 0.08 (95\%CI, 0.95-1.1) vs. PMR, 0.92 ± 0.1 (95\%CI, 0.85-0.99), p = 0.07), but not when compared to PMR + GCA (1.04 ± 0.14 (95\%CI, 0.95-1.13), p = 1). JLR of individuals finally diagnosed with PMR (0.94 ± 0.16, (95\%CI, 0.83-1.06)), however, was significantly increased relative to JLR in GCA (0.58 ± 0.04 (95\%CI, 0.55-0.61)) and GCA + PMR (0.64 ± 0.09 (95\%CI, 0.57-0.71); p < 0.0001, respectively). In individuals with a suspected diagnosis of rheumatic disease, an inflammatory-directed [\(^{18}\)F]FDG PET/CT can alter diagnosis in the majority of the cases, particularly in subjects who were referred because of diagnostic uncertainty. Semi-quantitative assessment may be helpful in establishing a final diagnosis of PMR, supporting the notion that a quantitative whole-body read-out may be useful in unclear cases.}, 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{BuderLapaKreissletal.2014, author = {Buder, Kristina and Lapa, Constantin and Kreissl, Michael C. and Schirbel, Andreas and Herrmann, Ken and Schnack, Alexander and Br{\"o}cker, Eva-Bettina and Goebeler, Matthias and Buck, Andreas K. and Becker, J{\"u}rgen C.}, title = {"Somatostatin receptor expression in Merkel cell carcinoma as target for molecular imaging"}, doi = {10.1186/1471-2407-14-268}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110326}, year = {2014}, abstract = {Background Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment. Methods To non-invasively assess SSTR expression in MCC using PET and the radiotracers [68Ga]DOTA-D-Phe1-Tyr3-octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT). Results SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73\% for nodal metastases, 100\% for bone, and 67\% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17\%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13\%). Conclusion SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management.}, 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{BrumbergKuestersAlMomanietal.2017, author = {Brumberg, Joachim and K{\"u}sters, Sebastian and Al-Momani, Ehab and Marotta, Giorgio and Cosgrove, Kelly P. and van Dyck, Christopher H. and Herrmann, Ken and Homola, Gy{\"o}rgy A. and Pezzoli, Gianni and Buck, Andreas K. and Volkmann, Jens and Samnick, Samuel and Isaias, Ioannis U.}, title = {Cholinergic activity and levodopa-induced dyskinesia: a multitracer molecular imaging study}, series = {Annals of Clinical and Translational Neurology}, volume = {4}, journal = {Annals of Clinical and Translational Neurology}, number = {9}, doi = {10.1002/acn3.438}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170406}, pages = {632-639}, year = {2017}, abstract = {Objective: To investigate the association between levodopa-induced dyskinesias and striatal cholinergic activity in patients with Parkinson's disease. Methods: This study included 13 Parkinson's disease patients with peak-of-dose levodopa-induced dyskinesias, 12 nondyskinetic patients, and 12 healthy controls. Participants underwent 5-[\(^{123}\)I]iodo-3-[2(S)-2-azetidinylmethoxy]pyridine single-photon emission computed tomography, a marker of nicotinic acetylcholine receptors, [\(^{123}\)I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane single-photon emission computed tomography, to measure dopamine reuptake transporter density and 2-[\(^{18}\)F]fluoro-2-deoxyglucose positron emission tomography to assess regional cerebral metabolic activity. Striatal binding potentials, uptake values at basal ganglia structures, and correlations with clinical variables were analyzed. Results: Density of nicotinic acetylcholine receptors in the caudate nucleus of dyskinetic subjects was similar to that of healthy controls and significantly higher to that of nondyskinetic patients, in particular, contralaterally to the clinically most affected side. Interpretation: Our findings support the hypothesis that the expression of dyskinesia may be related to cholinergic neuronal excitability in a dopaminergic-depleted striatum. Cholinergic signaling would play a role in maintaining striatal dopaminergic responsiveness, possibly defining disease phenotype and progression.}, language = {en} } @article{BreunMonoranuKessleretal.2019, author = {Breun, Maria and Monoranu, Camelia M. and Kessler, Almuth F. and Matthies, Cordula and L{\"o}hr, Mario and Hagemann, Carsten and Schirbel, Andreas and Rowe, Steven P. and Pomper, Martin G. and Buck, Andreas K. and Wester, Hans-J{\"u}rgen and Ernestus, Ralf-Ingo and Lapa, Constantin}, title = {[\(^{68}\)Ga]-Pentixafor PET/CT for CXCR4-mediated imaging of vestibular schwannomas}, series = {Frontiers in Oncology}, volume = {9}, journal = {Frontiers in Oncology}, number = {503}, doi = {10.3389/fonc.2019.00503}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201863}, year = {2019}, abstract = {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.}, language = {en} }