@inproceedings{WernerHayakawaAriasLozaetal.2017, author = {Werner, Rudolf and Hayakawa, Nobuyuki and Arias-Loza, Paula-Anah and Wakabayashi, Hiroshi and Shinaji, Tetsuya and Lapa, Constantin and Pelzer, Theo and Higuchi, Takahiro}, title = {Bildgebung der fr{\"u}hen linksventrikul{\"a}ren Dysfunktion mit ECG-gated F-18-FDG PET in einem Diabetes-Ratten-Modell}, series = {Nuklearmedizin}, volume = {56}, booktitle = {Nuklearmedizin}, number = {2}, publisher = {Schattauer Verlag}, issn = {0029-5566}, doi = {10.3413/Nukmed-0880-17-02}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161396}, pages = {Abstract Nr.: V119}, year = {2017}, abstract = {Einleitung: Die linksventrikul{\"a}re diastolische Dysfunktion (LVDD) ist bei Diabetikern noch vor Entwicklung einer klinisch apparenten Herzinsuffizienz eines der ersten Anzeichen einer kardialen Beteiligung. Daher soll in dieser Studie untersucht werden, ob die LVDD mit ECG-gated F-18-FDG PET in einem Diabetes-Rattenmodell dargestellt werden kann. Methodik: Es wurden F-18-FDG PET Scans in einem Typ-2-Diabetes Rattenmodell (ZDF fa/fa, n=6) und in ZL Kontrollen (n=6) vorgenommen (Alter, jeweils 13 Wochen). Unter Hyperinsulinemic-Euglycemic Clamp-Technik wurden 37 MBq 18F-FDG {\"u}ber die Schwanzvene appliziert. 15-35 Minuten nach Tracergabe wurden mittels eines Kleintier-PET-Scanners sowie unter EKG-Ableitung PET Scans angefertigt (16 frames/cardiac cycle). Die linksventrikul{\"a}re Ejektionsfraktion (EF) und die Peak F{\"u}llrate (PFR) wurden mittels einer geeigneten Software (Heart Function View) gemessen, wobei die Software an die Gr{\"o}ße des Rattenherzes angepasst wurde. Ergebnisse: Im Alter von 13 Wochen entwickeln ZDF Diabetes-Ratten eine im Vergleich zu Kontrolltieren eine signifikante myokardiale Hypertrophie, best{\"a}tigt durch post-mortem Analyse des Herzgewichtes (994±78mg vs. 871±44mg in ZDF Diabetes-Ratten vs. ZL Kontrollen, p<0.01). ECG-gated PET zeigte eine signifikante Abnahme der LV diastolischen PFR (10.4±0.5 vs. 11.8±0.4 EDV/sec in ZDF Diabetes-Ratten vs. ZL Kontrollen, p<0.001), jedoch zeigte sich kein signifikanter Unterschied zwischen LVEF und der Herzfrequenz in den untersuchten ZDF Diabetes-Ratten und Kontrollen (LVEF: 60.0±4.5 vs. 63.7±4.1\%, n.s. und HR: 305±25 vs. 323±24 bpm, n.s.). Schlussfolgerung: Im Diabetes-Ratten-Modell kann unter Verwendung eines ECG-gated FDG-PET Protokolls die diastolische Dysfunktion als Parameter der fr{\"u}hen diabetischen Kardiomyopathie nachgewiesen werden.}, subject = {Positronen-Emissions-Tomografie}, language = {de} } @article{WernerSchmidHiguchietal.2018, author = {Werner, Rudolf and Schmid, Jan-Stefan and Higuchi, Takahiro and Javadi, Mehrbod S. and Rowe, Steven P. and M{\"a}rkl, Bruno and Aulmann, Christoph and Fassnacht, Martin and Kroiß, Matthias and Reiners, Christoph and Buck, Andreas and Kreissl, Michael and Lapa, Constantin}, title = {Predictive value of \(^{18}\)F-FDG PET in patients with advanced medullary thyroid carcinoma treated with vandetanib}, series = {Journal of Nuclear Medicine}, journal = {Journal of Nuclear Medicine}, issn = {0161-5505}, doi = {10.2967/jnumed.117.199778}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161256}, year = {2018}, abstract = {Introduction: Therapeutic options in advanced medullary thyroid carcinoma (MTC) have markedly improved since the introduction of tyrosine kinase inhibitors (TKI). We aimed to assess the role of metabolic imaging using 2-deoxy-2-(\(^{18}\)F)fluoro-D-glucose (\(^{18}\)F-FDG) positron emission tomography/computed tomography (PET/CT) shortly before and 3 months after initiation of TKI treatment. Methods: Eighteen patients with advanced and progressive MTC scheduled for vandetanib treatment underwent baseline \(^{18}\)F-FDG PET/CT prior to and 3 months after TKI treatment initiation. During follow-up, CT scans were performed every 3 months and analyzed according to Response Evaluation Criteria In Solid Tumors (RECIST). The predictive value for estimating progression-free (PFS) and overall survival (OS) was examined by investigating \(^{18}\)F-FDG mean/maximum standardized uptake values (SUVmean/max) of the metabolically most active lesion as well as by analyzing clinical parameters (tumor marker doubling times {calcitonin, carcinoembryonic antigen (CEA)}, prior therapies, RET (rearranged during transfection) mutational status, and disease type). Results: Within a median follow-up of 5.2 years, 9 patients experienced disease progression after a median time interval of 2.1y whereas the remainder had ongoing disease control (n=5 partial response and n=4 stable disease). Eight of the 9 patients with progressive disease died from MTC after a median of 3.5y after TKI initiation. Pre-therapeutic SUVmean >4.0 predicted a significantly shorter PFS (PFS: 1.9y vs. 5.2y; p=0.04). Furthermore, sustained high 18F-FDG uptake at 3 months with a SUVmean>2.8 tended to portend an unfavorable prognosis with a PFS of 1.9y (vs. 3.5y; p=0.3). Prolonged CEA doubling times were significantly correlated with longer PFS (r=0.7) and OS (r=0.76, p<0.01, respectively). None of the other clinical parameters had prognostic significance. Conclusions: Pre-therapeutic \(^{18}\)F-FDG PET/CT holds prognostic information in patients with advanced MTC scheduled for treatment with the TKI vandetanib. Low tumor metabolism of SUVmean < 4.0 prior to treatment predicts longer progression-free survival.}, subject = {Medull{\"a}rer Schilddr{\"u}senkrebs}, language = {en} } @article{WernerWakabyashiChenetal.2018, author = {Werner, Rudolf and Wakabyashi, Hiroshi and Chen, Xinyu and Hirano, Mitsuru and Shinaji, Tetsuya and Lapa, Constantin and Rowe, Steven and Javadi, Mehrbod and Higuchi, Takahiro}, title = {Functional renal imaging with \(^{18}\)F-FDS PET in rat models of renal disorders}, series = {Journal of Nuclear Medicine}, journal = {Journal of Nuclear Medicine}, issn = {0161-5505}, doi = {10.2967/jnumed.117.203828}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161279}, year = {2018}, abstract = {Background: Precise regional quantitative assessment of renal function is limited with conventional \(^{99m}\)Tc-labeled renal radiotracers. A recent study reported that the positron emission tomography (PET) radiotracer 2-deoxy-2-(\(^{18}\)F-fluorosorbitol (\(^{18}\)F-FDS) has ideal pharmacokinetics for functional renal imaging. Furthermore, (\(^{18}\)F-FDS is available via simple reduction from routinely used 2-deoxy-2-(\(^{18}\)F-fluoro-D-glucose ((\(^{18}\)F-FDG). We aimed to further investigate the potential of (\(^{18}\)F-FDS PET as a functional renal imaging agent using rat models of kidney diseases. Methods: Two different rat models of renal impairment were investigated: Glycerol induced acute renal failure (ARF) by intramuscular administration of glycerol in hind legs and unilateral ureteral obstruction (UUO) by ligation of the left ureter. 24h after these treatments, dynamic 30 min 18F-FDS PET data were acquired using a dedicated small animal PET system. Urine 18F-FDS radioactivity 30 min after radiotracer injection was measured together with co-injected \(^{99m}\)Tc-diethylenetriaminepentaacetic acid (\(^{99m}\)Tc-DTPA) urine activity. Results: Dynamic PET imaging demonstrated rapid (\(^{18}\)F-FDS accumulation in the renal cortex and rapid radiotracer excretion via kidneys in control healthy rats. On the other hand, significantly delayed renal radiotracer uptake (continuous slow uptake) was observed in ARF rats and UUO-treated kidneys. Measured urine radiotracer concentrations of (\(^{18}\)F-FDS and \(^{99m}\)Tc-DTPA were well correlated (R=0.84, P<0.05). Conclusions: (\(^{18}\)F-FDS PET demonstrated favorable kinetics for functional renal imaging in rat models of kidney diseases. Advantages of high spatiotemporal resolution of PET imaging and simple tracer production could potentially complement or replace conventional renal scintigraphy in select cases and significantly improve the diagnostic performance of renal functional imaging.}, subject = {Nierenfunktionsst{\"o}rung}, language = {en} } @article{WernerKobayashiJavadietal.2018, author = {Werner, Rudolf A. and Kobayashi, Ryohei and Javadi, Mehrbod Som and K{\"o}ck, Zoe and Wakabayashi, Hiroshi and Unterecker, Stefan and Nakajima, Kenichi and Lapa, Constantin and Menke, Andreas and Higuchi, Takahiro}, title = {Impact of Novel Antidepressants on Cardiac Metaiodobenzylguanidine (mIBG) Uptake: Experimental Studies in SK-N-SH Cells and Healthy Rabbits}, series = {Journal of Nuclear Medicine}, journal = {Journal of Nuclear Medicine}, issn = {0161-5505}, doi = {10.2967/jnumed.117.206045}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161280}, year = {2018}, abstract = {Background: \(^{123}\)I-metaiodobenzylguanidine (mIBG) provides independent prognostic value for risk stratification among heart failure patients, but the use of concomitant medication should not impact its quantitative information. We aimed to evaluate the four most-prescribed antidepressants currently used as a first‑line treatment for patients with major depressive disorder (MDD) and their potential on altering mIBG imaging results. Methods: The inhibition effect of four different types of antidepressants (desipramine, escitalopram, venlafaxine and bupropion) for MDD treatment on \(^{131}\)I-mIBG uptake was assessed by in-vitro cell uptake assays using human neuroblastoma SK-N-SH cells. The half maximal inhibitory concentration (IC50) of tracer uptake was determined from dose-response curves. To evaluate the effects of IV pretreatment with desipramine (1.5 mg/kg) and escitalopram (2.5, 15 mg/kg) on mIBG cardiac uptake, in-vivo planar 123I-mIBG scans in healthy New Zealand White Rabbits were conducted. Results: The IC50 values of desipramine, escitalopram, venlafaxine and bupropion on \(^{131}\)I-mIBG cellular uptake were 11.9 nM, 7.5 μM, 4.92 μM, and 12.9 μM, respectively. At the maximum serum concentration (Cmax, as derived by previous clinical trials), the inhibition rates of 131I-mIBG uptake were 90.6 \% for desipramine, 25.5 \% for venlafaxine, 11.7 \% for bupropion and 0.72 \% for escitalopram. A low inhibition rate for escitalopram in the cell uptake study triggered investigation of an in-vivo rabbit model: with dosage considerably higher than clinical practice, the non-inhibitory effect of escitalopram was confirmed. Furthermore, pretreatment with desipramine led to a marked reduction of cardiac 123I-mIBG uptake. Conclusions: In the present in-vitro binding assay and in-vivo rabbit study, the selective-serotonin reuptake inhibitor escitalopram had no major impact on neuronal cardiac mIBG uptake within therapeutic dose ranges, while other types of first-line antidepressants for MDD treatment led to a significant decrease. These preliminary results warrant further confirmatory clinical trials regarding the reliability of cardiac mIBG imaging, in particular, if the patient's neuropsychiatric status would not tolerate withdrawal of a potentially norepinephrine interfering antidepressant.}, subject = {Antidepressants}, language = {en} } @article{WernerSolnesJavadietal.2018, author = {Werner, Rudolf and Solnes, Lilja and Javadi, Mehrbod and Weich, Alexander and Gorin, Michael and Pienta, Kenneth and Higuchi, Takahiro and Buck, Andreas and Pomper, Martin and Rowe, Steven and Lapa, Constantin}, title = {SSTR-RADS Version 1.0 as a Reporting System for SSTR-PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework}, series = {Journal of Nuclear Medicine}, journal = {Journal of Nuclear Medicine}, issn = {0161-5505}, doi = {10.2967/jnumed.117.206631}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161298}, year = {2018}, abstract = {Reliable standards and criteria for somatostatin receptor (SSTR) positron emission tomography (PET) are still lacking. We herein propose a structured reporting system on a 5-point scale for SSTR-PET imaging, titled SSTR-RADS version 1.0, which might serve as a standardized assessment for both diagnosis and treatment planning in neuroendocrine tumors (NET). SSTR-RADS could guide the imaging specialist in interpreting SSTR-PET scans, facilitate communication with the referring clinician so that appropriate work-up for equivocal findings is pursued, and serve as a reliable tool for patient selection for planned Peptide Receptor Radionuclide Therapy.}, subject = {Standardisierung}, 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} } @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 = {The Impact of Ageing on Dopamine Transporter Imaging}, 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-162213}, pages = {1646}, year = {2018}, abstract = {No abstract available.}, subject = {Parkinson-Krankheit}, language = {en} } @inproceedings{WernerChenHiranoetal.2018, author = {Werner, Rudolf A. and Chen, Xinyu and Hirano, Mitsuru and Nose, Naoko and Lapa, Constantin and Javadi, Mehrbod S. and Higuchi, Takahiro}, title = {The Impact of Ageing on [\(^{11}\)C]meta-Hydroxyephedrine Uptake in the Rat Heart}, 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-162228}, pages = {100}, year = {2018}, abstract = {No abstract available.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{LapaAriasLozaHayakawaetal.2017, author = {Lapa, Constantin and Arias-Loza, Paula and Hayakawa, Nobuyuki and Wakabayashi, Hiroshi and Werner, Rudolf A. and Chen, Xinyu and Shinaji, Tetsuya and Herrmann, Ken and Pelzer, Theo and Higuchi, Takahiro}, title = {Whitening and impaired glucose utilization of brown adipose tissue in a rat model of type 2 diabetes mellitus}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, doi = {10.1038/s41598-017-17148-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159066}, pages = {16795}, year = {2017}, abstract = {Brown adipose tissue (BAT) is an attractive therapeutic target to combat diabetes and obesity due to its ability to increase glucose expenditure. In a genetic rat model (ZDF fa/fa) of type-2 diabetes and obesity, we aimed to investigate glucose utilization of BAT by \(^{18}\)F-FDG PET imaging. Male Zucker diabetic fatty (ZDF) and Male Zucker lean (ZL) control rats were studied at 13 weeks. Three weeks prior to imaging, ZDF rats were randomized into a no-restriction (ZDF-ND) and a mild calorie restriction (ZDF-CR) group. Dynamic \(^{18}\)F-FDG PET using a dedicated small animal PET system was performed under hyperinsulinemic-euglycemic clamp. \(^{18}\)F-FDG PET identified intense inter-scapular BAT glucose uptake in all ZL control rats, while no focally increased \(^{18}\)F-FDG uptake was detected in all ZDF-ND rats. Mild but significant improved BAT tracer uptake was identified after calorie restriction in diabetic rats (ZDF-CR). The weight of BAT tissue and fat deposits were significantly increased in ZDF-CR and ZDF-ND rats as compared to ZL controls, while UCP-1 and mitochondrial concentrations were significantly decreased. Whitening and severely impaired insulin-stimulated glucose uptake in BAT was confirmed in a rat model of type-2 diabetes. Additionally, calorie restriction partially restored the impaired BAT glucose uptake.}, language = {en} } @unpublished{WernerIlhanLehneretal.2018, author = {Werner, Rudolf A. and Ilhan, Harun and Lehner, Sebastian and Papp, L{\´a}szl{\´o} and Zs{\´o}t{\´e}r, Norbert and Schatka, Imke and Muegge, Dirk O. and Javadi, Mehrbod S. and Higuchi, Takahiro and Buck, Andreas K. and Bartenstein, Peter and Bengel, Frank and Essler, Markus and Lapa, Constantin and Bundschuh, Ralph A.}, title = {Pre-therapy Somatostatin-Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy}, series = {Molecular Imaging and Biology}, journal = {Molecular Imaging and Biology}, issn = {1536-1632}, doi = {https://doi.org/10.1007/s11307-018-1252-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164624}, year = {2018}, abstract = {Purpose: Early identification of aggressive disease could improve decision-support in pancreatic neuroendocrine tumor (pNET) patients prior to peptide receptor radionuclide therapy (PRRT). The prognostic value of intratumoral textural features (TF) determined by baseline somatostatin receptor (SSTR)-PET before PRRT was analyzed. Procedures: 31 patients with G1/G2 pNET were enrolled (G2, n=23/31). Prior to PRRT with [\(^{177}\)Lu]DOTATATE (mean, 3.6 cycles), baseline SSTR-PET/CT was performed. By segmentation of 162 (median per patient, 5) metastases, intratumoral TF were computed. The impact of conventional PET parameters (SUV\(_{mean/max}\)), imaging-based TF as well as clinical parameters (Ki67, CgA) for prediction of both progression-free (PFS) and overall survival (OS) after PRRT was evaluated. Results: Within a median follow-up of 3.7y, tumor progression was detected in 21 patients (median, 1.5y) and 13/31 deceased (median, 1.9y). In ROC analysis, the TF Entropy, reflecting derangement on a voxel-by-voxel level, demonstrated predictive capability for OS (cutoff=6.7, AUC=0.71, p=0.02). Of note, increasing Entropy could predict a longer survival (>6.7, OS=2.5y, 17/31), whereas less voxel-based derangement portended inferior outcome (<6.7, OS=1.9y, 14/31). These findings were supported in a G2 subanalysis (>6.9, OS=2.8y, 9/23 vs. <6.9, OS=1.9y, 14/23). Kaplan-Meier analysis revealed a significant distinction between high- and low-risk groups using Entropy (n=31, p<0.05). For those patients below the ROC-derived threshold, the relative risk of death after PRRT was 2.73 (n=31, p=0.04). Ki67 was negatively associated with PFS (p=0.002); however, SUVmean/max failed in prognostication (n.s.). Conclusions: In contrast to conventional PET parameters, assessment of intratumoral heterogeneity demonstrated superior prognostic performance in pNET patients undergoing PRRT. This novel PET-based strategy of outcome prediction prior to PRRT might be useful for patient risk stratification.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @inproceedings{WernerKobayashiWakabayashietal.2017, author = {Werner, Rudolf and Kobayashi, Ryohei and Wakabayashi, Hiroshi and Lapa, Constantin and Menke, Andreas and Higuchi, Takahiro}, title = {Effect of Antidepressants on Radiolabeled Metaiodobenzylguanidine (MIBG) Uptake}, series = {European Heart Journal - Cardiovascular Imaging}, volume = {18}, booktitle = {European Heart Journal - Cardiovascular Imaging}, number = {Supplement}, publisher = {Oxford University Press}, issn = {2047-2404}, doi = {10.1093/ehjci/jex080}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161116}, pages = {i52-53}, year = {2017}, abstract = {No abstract available.}, subject = {MIBG}, language = {en} } @inproceedings{WernerChenLapaetal.2017, author = {Werner, Rudolf and Chen, Xinyu and Lapa, Constantin and Robinson, Simon and Higuchi, Takahiro}, title = {Intracellular behavior of the novel sympathetic nerve agent \(^{18}\)F-LMI1195}, series = {Journal of Nuclear Cardiology}, volume = {24}, booktitle = {Journal of Nuclear Cardiology}, number = {4 Supplement (2017) Aug}, issn = {1071-3581}, doi = {10.1007/s12350-017-0984-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161137}, pages = {1461-1496}, year = {2017}, abstract = {No abstract available.}, subject = {Herz}, language = {en} } @inproceedings{WernerHiguchiMueggeetal.2017, author = {Werner, Rudolf and Higuchi, Takahiro and Muegge, Dirk and Javadi, Mehrbod S. and M{\"a}rkl, Bruno and Aulmann, Christoph and Buck, Andreas K. and Fassnacht, Martin and Lapa, Constantin and Kreissl, Michael C.}, title = {Predictive value of FDG-PET in patients with advanced medullary thyroid cancer undergoing vandetanib treatment}, series = {Journal of Nuclear Medicine}, volume = {58}, booktitle = {Journal of Nuclear Medicine}, number = {no. supplement 1}, issn = {0161-5505}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161147}, pages = {169}, year = {2017}, abstract = {Introduction: The prognosis of medullary thyroid carcinoma (MTC) is poor using common chemotherapeutic approaches. However, during the last years encouraging results of recently introduced tyrosine kinase inhibitors (TKI) such as vandetanib have been published. In this study we aimed to correlate the results of \(^{18}\)F-fluorodeoxyglucose ([\(^{18}\)F]FDG) positron emission tomography (PET) imaging with treatment outcome. Methods: Eighteen patients after thyroidectomy with recurrent/advanced MTC lesions receiving vandetanib (300 mg orally/day) could be analysed. A baseline \(^{18}\)F-FDG PET prior to and a follow-up \(^{18}\)F-FDG PET 3 months after TKI initiation were performed. During follow-up, tumor progression was assessed every 3 months including computed tomography according to RECIST. Progression-free survival (PFS) was correlated with the maximum standardized uptake value of \(^{18}\)F-FDG in lymph nodes (SUV(LN)max) or visceral metastases (SUV(MTS)max) as well as with clinical parameters using ROC analysis. Results: Within median 3.6 years of follow-up, 9 patients showed disease progression at median 8.5 months after TKI initiation. An elevated glucose consumption assessed by baseline \(^{18}\)F-FDG PET (SUV(LN)max > 7.25) could predict a shorter PFS (2 y) with an accuracy of 76.5\% (SUV(LN)max <7.25, 4.3 y; p=0.03). Accordingly, preserved tumor metabolism in the follow-up PET (SUV(MTS)max >2.7) also demonstrated an unfavorable prognosis (accuracy, 85.7\%). On the other hand, none of the clinical parameters reached significance in response prediction. Conclusions: In patients with advanced and progressive MTC, tumors with higher metabolic activity at baseline are more aggressive and more prone to progression as reflected by a shorter PFS; they should be monitored more closely. Preserved glucose consumption 3 months after treatment initiation was also related to poorer prognosis.}, language = {en} } @inproceedings{WernerLapaBucketal.2017, author = {Werner, Rudolf and Lapa, Constantin and Buck, Andreas and Lassmann, Michael and H{\"a}nscheid, Heribert}, title = {Less is sometimes more - Accurate Dose Mapping after Endoradiotherapy with \(^{177}\)Lu-DOTATATE/-TOC by One-Single Measurement after 96 h}, series = {Journal of Nuclear Medicine}, volume = {58}, booktitle = {Journal of Nuclear Medicine}, number = {No. Supplement 1}, publisher = {Society of Nuclear Medicine and Molecular Imaging}, issn = {0161-5505}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161168}, pages = {247}, year = {2017}, abstract = {No abstract available.}, language = {en} } @unpublished{WernerBundschuhBundschuhetal.2019, author = {Werner, Rudolf A. and Bundschuh, Ralph A. and Bundschuh, Lena and Fanti, Stefano and Javadi, Mehrbod S. and Higuchi, Takahiro and Weich, A. and Pienta, Kenneth J. and Buck, Andreas K. and Pomper, Martin G. and Gorin, Michael A. and Herrmann, Ken and Lapa, Constantin and Rowe, Steven P.}, title = {Novel Structured Reporting Systems for Theranostic Radiotracers}, series = {Journal of Nuclear Medicine}, journal = {Journal of Nuclear Medicine}, issn = {0161-5505}, doi = {10.2967/jnumed.118.223537}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-174629}, year = {2019}, abstract = {Standardized reporting is more and more routinely implemented in clinical practice and such structured reports have a major impact on a large variety of medical fields, e.g. laboratory medicine, pathology, and, recently, radiology. Notably, the field of nuclear medicine is constantly evolving, as novel radiotracers for numerous clinical applications are developed. Thus, framework systems for standardized reporting in this field may a) increase clinical acceptance of new radiotracers, b) allow for inter- and intra-center comparisons for quality assurance, and c) may be used in (global) multi-center studies to ensure comparable results and enable efficient data abstraction. In the last two years, several standardized framework systems for positron emission tomography (PET) radiotracers with potential theranostic applications have been proposed. These include systems for prostate-specific membrane antigen (PSMA)-targeted PET agents for the diagnosis and treatment of prostate cancer (PCa) and somatostatin receptor (SSTR)-targeted PET agents for the diagnosis and treatment of neuroendocrine neoplasias. In the present review, those standardized framework systems for PSMA- and SSTR-targeted PET will be briefly introduced followed by an overview of their advantages and limitations. In addition, potential applications will be defined, approaches to validate such concepts will be proposed, and future perspectives will be discussed.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{LueckerathLapaAlbertetal.2015, author = {L{\"u}ckerath, Katharina and Lapa, Constantin and Albert, Christa and Herrmann, Ken and J{\"o}rg, Gerhard and Samnick, Samuel and Einsele, Herrmann and Knop, Stefan and Buck, Andreas K.}, title = {\(^{11}\)C-Methionine-PET: a novel and sensitive tool for monitoring of early response to treatment in multiple myeloma}, series = {Oncotarget}, volume = {6}, journal = {Oncotarget}, number = {10}, doi = {10.18632/oncotarget.3053}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148688}, pages = {8418-8429}, year = {2015}, abstract = {Multiple myeloma (MM) remains an essentially incurable hematologic malignancy. However, new treatment modalities and novel drugs have been introduced and thus additional tools for therapy monitoring are increasingly needed. Therefore, we evaluated the radiotracers \(^{11}\)C-Methionine (paraprotein-biosynthesis) and \(^{18}\)F-FDG (glucose-utilization) for monitoring response to anti-myeloma-therapy and outcome prediction. Influence of proteasome-inhibition on radiotracer-uptake of different MM cell-lines and patient-derived CD138\(^{+}\) plasma cells was analyzed and related to tumor-biology. Mice xenotransplanted with MM. 1S tumors underwent MET- and FDG-\(\mu\)PET. Tumor-to-background ratios before and after 24 h, 8 and 15 days treatment with bortezomib were correlated to survival. Treatment reduced both MET and FDG uptake; changes in tracer-retention correlated with a switch from high to low CD138-expression. In xenotransplanted mice, MET-uptake significantly decreased by 30-79\% as early as 24 h after bortezomib injection. No significant differences were detected thus early with FDG. This finding was confirmed in patient-derived MM cells. Importantly, early reduction of MET-but not FDG-uptake correlated with improved survival and reduced tumor burden in mice. Our results suggest that MET is superior to FDG in very early assessment of response to anti-myeloma-therapy. Early changes in MET-uptake have predictive potential regarding response and survival. MET-PET holds promise to individualize therapies in MM in future.}, language = {en} } @unpublished{WernerBundschuhBundschuhetal.2018, author = {Werner, Rudolf A. and Bundschuh, Ralph A. and Bundschuh, Lena and Javadi, Mehrbod S. and Leal, Jeffrey P. and Higuchi, Takahiro and Pienta, Kenneth J. and Buck, Andreas K. and Pomper, Martin G. and Gorin, Michael A. and Lapa, Constantin and Rowe, Steven P.}, title = {Interobserver Agreement for the Standardized Reporting System PSMA-RADS 1.0 on \(^{18}\)F-DCFPyL PET/CT Imaging}, series = {Journal of Nuclear Medicine}, journal = {Journal of Nuclear Medicine}, issn = {0161-5505}, doi = {10.2967/jnumed.118.217588}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167788}, year = {2018}, abstract = {Objectives: Recently, the standardized reporting and data system for prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging studies, termed PSMA-RADS version 1.0, was introduced. We aimed to determine the interobserver agreement for applying PSMA-RADS to imaging interpretation of 18F-DCFPyL PET examinations in a prospective setting mimicking the typical clinical work-flow at a prostate cancer referral center. Methods: Four readers (two experienced readers (ER, > 3 years of PSMA-targeted PET interpretation experience) and two inexperienced readers (IR, < 1 year of experience)), who had all read the initial publication on PSMA-RADS 1.0, assessed 50 18F-DCFPyL PET/computed tomography (CT) studies independently. Per scan, a maximum of 5 target lesions were selected by the observers and a PSMA-RADS score for every target lesion was recorded. No specific pre-existing conditions were placed on the selection of the target lesions, although PSMA-RADS 1.0 suggests that readers focus on the most highly avid or largest lesions. An overall scan impression based on PSMA-RADS was indicated and interobserver agreement rates on a target lesion-based, on an organ-based, and on an overall PSMA-RADS score-based level were computed. Results: The number of target lesions identified by each observer were as follows: ER 1, 123; ER 2, 134; IR 1, 123; and IR 2, 120. Among those selected target lesions, 125 were chosen by at least two individual observers (all four readers selected the same target lesion in 58/125 (46.4\%) instances, three readers in 40/125 (32\%) and two observers in 27/125 (21.6\%) instances). The interobserver agreement for PSMA-RADS scoring among identical target lesions was good (intraclass correlation coefficient (ICC) for four, three and two identical target lesions, ≥0.60, respectively). For lymph nodes, an excellent interobserver agreement was derived (ICC=0.79). The interobserver agreement for an overall scan impression based on PSMA-RADS was also excellent (ICC=0.84), with a significant difference for ER (ICC=0.97) vs. IR (ICC=0.74, P=0.005). Conclusions: PSMA-RADS demonstrates a high concordance rate in this study, even among readers with different levels of experience. This suggests that PSMA-RADS can be effectively used for communication with clinicians and can be implemented in the collection of data for large prospective trials.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @unpublished{YinWernerHiguchietal.2018, author = {Yin, Yafu and Werner, Rudolf A. and Higuchi, Takahiro and Lapa, Constantin and Pienta, Kenneth J. and Pomper, Martin G. and Gorin, Michael A. and Rowe, Steven P.}, title = {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}, series = {Journal of Nuclear Medicine}, journal = {Journal of Nuclear Medicine}, issn = {0161-5505}, doi = {10.2967/jnumed.118.217653}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167594}, year = {2018}, abstract = {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.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{LapaKircherSchirbeletal.2017, author = {Lapa, Constantin and Kircher, Stefan and Schirbel, Andreas and Rosenwald, Andreas and Kropf, Saskia and Pelzer, Theo and Walles, Thorsten and Buck, Andreas K. and Weber, Wolfgang A. and Wester, Hans-Juergen and Herrmann, Ken and L{\"u}ckerath, Katharina}, title = {Targeting CXCR4 with [\(^{68}\)Ga]Pentixafor: a suitable theranostic approach in pleural mesothelioma?}, series = {Oncotarget}, volume = {8}, journal = {Oncotarget}, number = {57}, doi = {10.18632/oncotarget.18235}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169989}, pages = {96732-96737}, 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. This study investigated the feasibility of CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using [\(^{68}\)Ga]Pentixafor in malignant pleural mesothelioma. Six patients with pleural mesothelioma underwent [\(^{68}\)Ga]Pentixafor-PET/CT. 2′-[\(^{18}\)F]fluoro-2′-deoxy-D-glucose ([\(^{18}\)F]FDG)-PET/CT (4/6 patients) and immunohistochemistry obtained from biopsy or surgery (all) served as standards of reference. Additionally, 9 surgical mesothelioma samples were available for histological work-up. Whereas [\(^{18}\)F]FDG-PET depicted active lesions in all patients, [\(^{68}\)Ga]Pentixafor-PET/CT recorded physiologic tracer distribution and none of the 6 patients presented [\(^{68}\)Ga]Pentixafor-positive lesions. This finding paralleled results of immunohistochemistry which also could not identify relevant CXCR4 surface expression in the samples analyzed. In contrast to past reports, our data suggest widely absence of CXCR4 expression in pleural mesothelioma. Hence, robust cell surface expression should be confirmed prior to targeting this chemokine receptor for diagnosis and/or therapy.}, language = {en} } @article{WernerWeichHiguchietal.2017, author = {Werner, Rudolf A. and Weich, Alexander and Higuchi, Takahiro and Schmid, Jan S. and Schirbel, Andreas and Lassmann, Michael and Wild, Vanessa and Rudelius, Martina and Kudlich, Theodor and Herrmann, Ken and Scheurlen, Michael and Buck, Andreas K. and Kropf, Saskia and Wester, Hans-J{\"u}rgen and Lapa, Constantin}, title = {Imaging of Chemokine Receptor 4 Expression in Neuroendocrine Tumors - a Triple Tracer Comparative Approach}, series = {Theranostics}, volume = {7}, journal = {Theranostics}, number = {6}, doi = {10.7150/thno.18754}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158008}, pages = {1489-1498}, year = {2017}, abstract = {C-X-C motif chemokine receptor 4 (CXCR4) and somatostatin receptors (SSTR) are overexpressed in gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). In this study, we aimed to elucidate the feasibility of non-invasive CXCR4 positron emission tomography/computed tomography (PET/CT) imaging in GEP-NET patients using [\(^{68}\)Ga]Pentixafor in comparison to \(^{68}\)Ga-DOTA-D-Phe-Tyr3-octreotide ([\(^{68}\)Ga]DOTATOC) and \(^{18}\)F-fluorodeoxyglucose ([\(^{18}\)F]FDG). Twelve patients with histologically proven GEP-NET (3xG1, 4xG2, 5xG3) underwent [\(^{68}\)Ga]DOTATOC, [\(^{18}\)F]FDG, and [\(^{68}\)Ga]Pentixafor PET/CT for staging and planning of the therapeutic management. Scans were analyzed on a patient as well as on a lesion basis and compared to immunohistochemical staining patterns of CXCR4 and somatostatin receptors SSTR2a and SSTR5. [\(^{68}\)Ga]Pentixafor visualized tumor lesions in 6/12 subjects, whereas [\(^{18}\)F]FDG revealed sites of disease in 10/12 and [\(^{68}\)Ga]DOTATOC in 11/12 patients, respectively. Regarding sensitivity, SSTR-directed PET was the superior imaging modality in all G1 and G2 NET. CXCR4-directed PET was negative in all G1 NET. In contrast, 50\% of G2 and 80\% of G3 patients exhibited [\(^{68}\)Ga]Pentixafor-positive tumor lesions. Whereas CXCR4 seems to play only a limited role in detecting well-differentiated NET, increasing receptor expression could be non-invasively observed with increasing tumor grade. Thus, [\(^{68}\)Ga]Pentixafor PET/CT might serve as non-invasive read-out for evaluating the possibility of CXCR4-directed endoradiotherapy in advanced dedifferentiated SSTR-negative tumors.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{WernerBeykanHiguchietal.2016, author = {Werner, Rudolf A. and Beykan, Seval and Higuchi, Takahiro and L{\"u}ckerath, Katharina and Weich, Alexander and Scheurlen, Michael and Bluemel, Christina and Herrmann, Ken and Buck, Andreas K. and Lassmann, Michael and Lapa, Constantin and H{\"a}nscheid, Heribert}, title = {The impact of \(^{177}\)Lu-octreotide therapy on \(^{99m}\)Tc-MAG3 clearance is not predictive for late nephropathy}, series = {Oncotarget}, volume = {7}, journal = {Oncotarget}, number = {27}, doi = {10.18632/oncotarget.9775}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177318}, pages = {41233-41241}, year = {2016}, abstract = {Peptide Receptor Radionuclide Therapy (PRRT) for the treatment of neuroendocrine tumors may lead to kidney deterioration. This study aimed to evaluate the suitability of \(^{99m}\)Tc-mercaptoacetyltriglycine (\(^{99m}\)Tc-MAG3) clearance for the early detection of PRRT-induced changes on tubular extraction (TE). TE rate (TER) was measured prior to 128 PRRT cycles (7.6±0.4 GBq \(^{177}\)Lu-octreotate/octreotide each) in 32 patients. TER reduction during PRRT was corrected for age-related decrease and analyzed for the potential to predict loss of glomerular filtration (GF). The GF rate (GFR) as measure for renal function was derived from serum creatinine. The mean TER was 234 ± 53 ml/min/1.73 m² before PRRT (baseline) and 221 ± 45 ml/min/1.73 m² after a median follow-up of 370 days. The age-corrected decrease (mean: -3\%, range: -27\% to +19\%) did not reach significance (p=0.09) but significantly correlated with the baseline TER (Spearman p=-0.62, p<0.001). Patients with low baseline TER showed an improved TER after PRRT, high decreases were only observed in individuals with high baseline TER. Pre-therapeutic TER data were inferior to plasma creatinine-derived GFR estimates in predicting late nephropathy. TER assessed by \(^{99m}\)Tc-MAG3­clearance prior to and during PRRT is not suitable as early predictor of renal injury and an increased risk for late nephropathy.}, language = {en} } @article{LapaReiterKircheretal.2016, author = {Lapa, Constantin and Reiter, Theresa and Kircher, Malte and Schirbel, Andreas and Werner, Rudolf A. and Pelzer, Theo and Pizarro, Carmen and Skowasch, Dirk and Thomas, Lena and Schlesinger-Irsch, Ulrike and Thomas, Daniel and Bundschuh, Ralph A. and Bauer, Wolfgang R. and Gartner, Florian C.}, title = {Somatostatin receptor based PET/CT in patients with the suspicion of cardiac sarcoidosis: an initial comparison to cardiac MRI}, series = {Oncotarget}, volume = {7}, journal = {Oncotarget}, number = {47}, doi = {10.18632/oncotarget.12799}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175423}, pages = {77807-77814}, year = {2016}, abstract = {Diagnosis of cardiac sarcoidosis is often challenging. Whereas cardiac magnetic resonance imaging (CMR) and positron emission tomography/computed tomography (PET/CT) with \(^{18}\)F-fluorodeoxyglucose (FDG) are most commonly used to evaluate patients, PET/CT using radiolabeled somatostatin receptor (SSTR) ligands for visualization of inflammation might represent a more specific alternative. This study aimed to investigate the feasibility of SSTR-PET/CT for detecting cardiac sarcoidosis in comparison to CMR. 15 patients (6 males, 9 females) with sarcoidosis and suspicion on cardiac involvement underwent SSTR-PET/CT imaging and CMR. Images were visually scored. The AHA 17-segment model of the left myocardium was used for localization and comparison of inflamed myocardium for both imaging modalities. In semi-quantitative analysis, mean (SUV\(_{mean}\)) and maximum standardized uptake values (SUV\(_{max}\)) of affected myocardium were calculated and compared with both remote myocardium and left ventricular (LV) cavity. SSTR-PET was positive in 7/15, CMR in 10/15 patients. Of the 3 CMR+/PET- subjects, one patient with minor involvement (<25\% of wall thickness in CMR) was missed by PET. The remaining two CMR+/PET- patients displayed no adverse cardiac events during follow-up. In the 17-segment model, PET/CT yielded 27 and CMR 29 positive segments. Overall concordance of the 2 modalities was 96.1\% (245/255 segments analyzed). SUV\(_{mean}\) and SUV\(_{max}\) in inflamed areas were 2.0±1.2 and 2.6±1.2, respectively. The lesion-to-remote myocardium and lesion-to-LV cavity ratios were 1.8±0.2 and 1.9±0.2 for SUV\(_{mean}\) and 2.0±0.3 and 1.7±0.3 for SUV\(_{max}\), respectively. Detection of cardiac sarcoidosis by SSTR-PET/CT is feasible. Our data warrant further analysis in larger prospective series.}, language = {en} } @article{LapaWernerBluemeletal.2014, author = {Lapa, Constantin and Werner, Rudolf A. and Bluemel, Christina and Lueckerath, Katharina and Muegge, Dirk O. and Strate, Alexander and Haenscheid, Heribert and Schirbel, Andreas and Allen-Auerbach, Martin S. and Bundschuh, Ralph A. and Buck, Andreas K. and Herrmann, Ken}, title = {Prediction of clinically relevant hyperkalemia in patients treated with peptide receptor radionuclide therapy}, series = {EJNMMI Research}, volume = {4}, journal = {EJNMMI Research}, number = {74}, doi = {10.1186/s13550-014-0074-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124963}, year = {2014}, abstract = {Background Peptide receptor radionuclide therapy (PRRT) is applied in patients with advanced neuroendocrine tumors. Co-infused amino acids (AA) should prevent nephrotoxicity. The aims of this study were to correlate the incidence of AA-induced hyperkalemia (HK) (≥5.0 mmol/l) and to identify predictors of AA-induced severe HK (>6.0). Methods In 38 patients, standard activity of \(^{177}Lu\)-labelled somatostatin analogs was administered. Pre-therapeutic kidney function was assessed by renal scintigraphy and laboratory tests. For kidney protection, AA was co-infused. Biochemical parameters (potassium, glomerular filtration rate, creatinine, blood urea nitrogen (BUN), sodium, phosphate, chloride, and lactate dehydrogenase (LDH)) were obtained prior to 4 and 24 h after the AA infusion. Incidence of HK (≥5.0) was correlated with pre-therapeutic kidney function and serum parameters. Formulas for the prediction of severe hyperkalemia (>6.0) were computed and prospectively validated. Results At 4 h, HK (≥5.0) was present in 94.7\% with severe HK (>6.0) in 36.1\%. Values normalized after 24 h in 84.2\%. Pre-therapeutic kidney function did not correlate with the incidence of severe HK. Increases in K+ were significantly correlated with decreases in phosphate (r = -0.444, p < 0.005) and increases in BUN (r = 0.313, p = 0.056). A baseline BUN of >28 mg/dl had a sensitivity of 84.6\% and a specificity of 60.0\% (AUC = 0.75) in predicting severe HK of >6.0 (phosphate, AUC = 0.37). Computing of five standard serum parameters (potassium, BUN, sodium, phosphate, LDH) resulted in a sensitivity of 88.9\% and a specificity of 79.3\% for the prediction of severe HK >6.0 (accuracy = 81.6\%). Conclusions A combination of serum parameters predicted prospectively the occurrence of relevant HK with an accuracy of 81.6\% underlining its potential utility for identifying 'high-risk' patients prone to PRRT.}, language = {en} } @article{LapaLinsenmannLueckerathetal.2015, author = {Lapa, Constantin and Linsenmann, Thomas and L{\"u}ckerath, Katharina and Samnick, Samuel and Herrmann, Ken and Stoffer, Carolin and Ernestus, Ralf-Ingo and Buck, Andreas K. and L{\"o}hr, Mario and Monoranu, Camelia-Maria}, title = {Tumor-Associated Macrophages in Glioblastoma Multiforme—A Suitable Target for Somatostatin Receptor-Based Imaging and Therapy?}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {3}, doi = {10.1371/journal.pone.0122269}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125498}, pages = {e0122269}, year = {2015}, abstract = {Background Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Tumor-associated macrophages (TAM) have been shown to promote malignant growth and to correlate with poor prognosis. [1,4,7,10-tetraazacyclododecane-NN′,N″,N′″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) labeled with Gallium-68 selectively binds to somatostatin receptor 2A (SSTR2A) which is specifically expressed and up-regulated in activated macrophages. On the other hand, the role of SSTR2A expression on the cell surface of glioma cells has not been fully elucidated yet. The aim of this study was to non-invasively assess SSTR2A expression of both glioma cells as well as macrophages in GBM. Methods 15 samples of patient-derived GBM were stained immunohistochemically for macrophage infiltration (CD68), proliferative activity (Ki67) as well as expression of SSTR2A. Anti-CD45 staining was performed to distinguish between resident microglia and tumor-infiltrating macrophages. In a subcohort, positron emission tomography (PET) imaging using \(^{68}Ga-DOTATATE\) was performed and the semiquantitatively evaluated tracer uptake was compared to the results of immunohistochemistry. Results The amount of microglia/macrophages ranged from <10\% to >50\% in the tumor samples with the vast majority being resident microglial cells. A strong SSTR2A immunostaining was observed in endothelial cells of proliferating vessels, in neurons and neuropile. Only faint immunostaining was identified on isolated microglial and tumor cells. Somatostatin receptor imaging revealed areas of increased tracer accumulation in every patient. However, retention of the tracer did not correlate with immunohistochemical staining patterns. Conclusion SSTR2A seems not to be overexpressed in GBM samples tested, neither on the cell surface of resident microglia or infiltrating macrophages, nor on the surface of tumor cells. These data suggest that somatostatin receptor directed imaging and treatment strategies are less promising in GBM.}, language = {en} } @article{BrumbergBecklDierksetal.2020, author = {Brumberg, Joachim and Beckl, Melanie and Dierks, Alexander and Schirbel, Andreas and Krebs, Markus and Buck, Andreas and K{\"u}bler, Hubert and Lapa, Constantin and Seitz, Anna Katharina}, title = {Detection Rate of \(^{68}\)Ga-PSMA Ligand PET/CT in Patients with Recurrent Prostate Cancer and Androgen Deprivation Therapy}, series = {Biomedicines}, volume = {8}, journal = {Biomedicines}, number = {11}, issn = {2227-9059}, doi = {10.3390/biomedicines8110511}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219301}, year = {2020}, abstract = {Prostate-specific membrane antigen (PSMA) ligand PET/CT enables the localization of tumor lesions in patients with recurrent prostate cancer, but it is unclear whether androgen deprivation therapy (ADT) influences diagnostic accuracy. The aim of this study was to evaluate the effect of ADT on the detection rate of \(^{68}\)Ga-PSMA ligand PET/CT. Thus, 399 patients with initial radical prostatectomy and 68Ga-PSMA ligand PET/CT during PSA relapse were retrospectively evaluated. Propensity score matching was used to create two balanced groups of 62 subjects who either did or did not receive ADT within six months before imaging. All \(^{68}\)Ga-PSMA ligand PET/CT were evaluated visually and with semiquantitative measures. The detection rate of tumor recurrence was significantly higher in the group with ADT (88.7\% vs. 72.6\%, p = 0.02) and improved with increasing PSA-levels in both groups. In subjects with pathological PET/CT and ADT, whole-body total lesion PSMA (p < 0.01) and PSMA-derived tumor volume (p < 0.01) were significantly higher than in those without ADT. More PSMA-positive lesions and higher PSMA-derived volumetric parameters in patients with ADT suggest that a better detection rate is related to a (biologically) more advanced disease stage. Due to high detection rates in patients with PSA-levels < 2 ng/mL, the withdrawal of ADT before PSMA ligand PET/CT cannot be recommended.}, language = {en} } @article{KlaesnerBuchmannGemptetal.2015, author = {Kl{\"a}sner, Benjamin and Buchmann, Niels and Gempt, Jens and Ringel, Florian and Lapa, Constantin and Krause, Bernd Joachim}, title = {Early [\(^{18}\)F]FET-PET in Gliomas after Surgical Resection: Comparison with MRI and Histopathology}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0141153}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-139549}, pages = {e0141153}, year = {2015}, abstract = {Background The precise definition of the post-operative resection status in high-grade gliomas (HGG) is crucial for further management. We aimed to assess the feasibility of assessment of the resection status with early post-operative positron emission tomography (PET) using [\(^{18}\)F]O-(2-[\(^{18}\)F]-fluoroethyl)-L-tyrosine ([\(^{18}\)F]FET). Methods 25 patients with the suspicion of primary HGG were enrolled. All patients underwent preoperative [\(^{18}\)F]FET-PET and magnetic resonance imaging (MRI). Intra-operatively, resection status was assessed using 5-aminolevulinic acid (5-ALA). Imaging was repeated within 72h after neurosurgery. Post-operative [\(^{18}\)F]FET-PET was compared with MRI, intra-operative assessment and clinical follow-up. Results [\(^{18}\)F]FET-PET, MRI and intra-operative assessment consistently revealed complete resection in 12/25 (48\%) patients and incomplete resection in 6/25 cases (24\%). In 7 patients, PET revealed discordant findings. One patient was re-resected. 3/7 experienced tumor recurrence, 3/7 died shortly after brain surgery. Conclusion Early assessment of the resection status in HGG with [\(^{18}\)F]FET-PET seems to be feasible.}, language = {en} } @article{LueckerathLapaMalzahnetal.2014, author = {L{\"u}ckerath, Katharina and Lapa, Constantin and Malzahn, Uwe and Samnick, Samuel and Einsele, Herrmann and Buck, Andreas K. and Herrmann, Ken and Knop, Stefan}, title = {18FDG-PET/CT for prognostic stratification of patients with multiple myeloma relapse after stem cell transplantation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-113107}, year = {2014}, abstract = {The aim of this study was to investigate the prognostic value of 18F-fluoro-deoxyglucose positron emission tomography-computed tomography (18F-FDG-PET/CT) in 37 patients with a history of multiple myeloma (MM) and suspected or confirmed recurrence after stem cell transplantation (SCT). All patients had been heavily pre-treated. Time to progression (TTP) and overall survival (OS) were correlated to a number of different PET-derived as well as clinical parameters. Impact on patient management was assessed. Absence of FDG-avid MM foci was a positive prognostic factor for both TTP and OS (p<0.01). Presence of >10 focal lesions correlated with both TTP (p<0.01) and OS (p<0.05). Interestingly, presence of >10 lesions in the appendicular skeleton proved to have the strongest association with disease progression. Intensity of glucose uptake and presence of extramedullary disease were associated with shorter TTP (p=0.037 and p=0.049, respectively). Manifestations in soft tissue structures turned out to be a strong negative predictor for both, TTP and OS (p<0.01, respectively). PET resulted in a change of management in 30\% of patients. Our data underline the prognostic value of 18F-FDG-PET/CT in MM patients also in the setting of post-SCT relapse. PET/CT has a significant impact on patient management.}, language = {en} } @article{LueckerathLapaSpahmannetal.2013, author = {L{\"u}ckerath, Katharina and Lapa, Constantin and Spahmann, Annika and J{\"o}rg, Gerhard and Samnick, Samuel and Rosenwald, Andreas and Einsele, Herrmann and Knop, Stefan and Buck, Andreas}, title = {Targeting Paraprotein Biosynthesis for Non-Invasive Characterization of Myeloma Biology}, doi = {10.1371/journal.pone.0084840}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111319}, year = {2013}, abstract = {Purpose Multiple myeloma is a hematologic malignancy originating from clonal plasma cells. Despite effective therapies, outcomes are highly variable suggesting marked disease heterogeneity. The role of functional imaging for therapeutic management of myeloma, such as positron emission tomography with 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG-PET), remains to be determined. Although some studies already suggested a prognostic value of 18F-FDG-PET, more specific tracers addressing hallmarks of myeloma biology, e.g. paraprotein biosynthesis, are needed. This study evaluated the amino acid tracers L-methyl-[11C]-methionine (11C-MET) and [18F]-fluoroethyl-L-tyrosine (18F-Fet) for their potential to image myeloma and to characterize tumor heterogeneity. Experimental Design To study the utility of 11C-MET, 18F-Fet and 18F-FDG for myeloma imaging, time activity curves were compared in various human myeloma cell lines (INA-6, MM1.S, OPM-2) and correlated to cell-biological characteristics, such as marker gene expression and immunoglobulin levels. Likewise, patient-derived CD138+ plasma cells were characterized regarding uptake and biomedical features. Results Using myeloma cell lines and patient-derived CD138+ plasma cells, we found that the relative uptake of 11C-MET exceeds that of 18F-FDG 1.5- to 5-fold and that of 18F-Fet 7- to 20-fold. Importantly, 11C-MET uptake significantly differed between cell types associated with worse prognosis (e.g. t(4;14) in OPM-2 cells) and indolent ones and correlated with intracellular immunoglobulin light chain and cell surface CD138 and CXCR4 levels. Direct comparison of radiotracer uptake in primary samples further validated the superiority of 11C-MET. Conclusion These data suggest that 11C-MET might be a versatile biomarker for myeloma superior to routine functional imaging with 18F-FDG regarding diagnosis, risk stratification, prognosis and discrimination of tumor subtypes.}, 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{WernerLapaBluemeletal.2014, author = {Werner, Rudolf A. and Lapa, Constantin and Bluemel, Christina and L{\"u}ckerath, Katharina and Schirbel, Andreas and Strate, Alexander and Buck, Andreas K. and Herrmann, Ken}, title = {Influence of the amount of co-infused amino acids on post-therapeutic potassium levels in peptide receptor radionuclide therapy}, doi = {10.1186/s13550-014-0046-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110617}, year = {2014}, abstract = {Background Peptide receptor radionuclide therapy (PRRT) is routinely used for advanced or metastasized neuroendocrine tumours (NET). To prevent nephrotoxicity, positively charged amino acids (AA) are co-infused. The aim of this study was to correlate the risk for therapy-related hyperkalaemia with the total amount of AA infused. Methods Twenty-two patients undergoing PRRT with standard activities of 177Lu-DOTATATE/-TOC were monitored during two following treatment cycles with co-infusion of 75 and 50 g of AA (L-arginine and L-lysine), respectively. Mean serum levels of potassium and other parameters (glomerular filtration rate [GFR], creatinine, blood urea nitrogen [BUN], phosphate, chloride, lactate dehydrogenase) prior to, 4 h and 24 h after AA infusion were compared. Results Self-limiting hyperkalaemia (>5.0 mmol/l) resolving after 24 h occurred in 91\% (20/22) of patients in both protocols. Potassium levels, BUN, creatinine, GFR, phosphate, chloride and LDH showed a similar range at 4 h after co-infusion of 75 or 50 g of AA, respectively (p > 0.05). Only GFR and creatinine levels at 24 h varied significantly between the two co-infusion protocols (p < 0.05). Conclusions Hyperkalaemia is a frequent side effect of AA infusion in PRRT. Varying the dose of co-infused amino acids did not impact on the incidence and severity of hyperkalaemia.}, 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{LiSamnickLapaetal.2012, author = {Li, Xiang and Samnick, Samuel and Lapa, Constantin and Israel, Ina and Buck, Andreas K. and Kreissl, Michael C. and Bauer, Wolfgang}, title = {68Ga-DOTATATE PET/CT for the detection of inflammation of large arteries: correlation with18F-FDG, calcium burden and risk factors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76231}, year = {2012}, abstract = {Background: Ga-[1,4,7,10-tetraazacyclododecane-N,N0,N00,N000-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) positron emission tomography (PET) is commonly used for the visualization of somatostatin receptor (SSTR)-positive neuroendocrine tumors. SSTR is also known to be expressed on macrophages, which play a major role in inflammatory processes in the walls of coronary arteries and large vessels. Therefore, imaging SSTR expression has the potential to visualize vulnerable plaques. We assessed 68Ga-DOTATATE accumulation in large vessels in comparison to 18F-2-fluorodeoxyglucose (FDG) uptake, calcified plaques (CPs), and cardiovascular risk factors. Methods: Sixteen consecutive patients with neuroendocrine tumors or thyroid cancer underwent both 68Ga-DOTATATE and 18F-FDG PET/CT for staging or restaging purposes. Detailed clinical data, including common cardiovascular risk factors, were recorded. For a separate assessment, they were divided into a high-risk and a low-risk group. In each patient, we calculated the maximum target-to-background ratio (TBR) of eight arterial segments. The correlation of the TBRmean of both tracers with risk factors including plaque burden was assessed. Results: The mean TBR of 68Ga-DOTATATE in all large arteries correlated significantly with the presence of CPs (r = 0.52; p < 0.05), hypertension (r = 0.60; p < 0.05), age (r = 0.56; p < 0.05), and uptake of 18F-FDG (r = 0.64; p < 0.01). There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05). Out of the 37 sites with the highest focal 68Ga-DOTATATE uptake, 16 (43.2\%) also had focal 18F-FDG uptake. Of 39 sites with the highest 18F-FDG uptake, only 11 (28.2\%) had a colocalized 68Ga-DOTATATE accumulation. Conclusions: In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries. Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.}, subject = {Medizin}, language = {en} } @article{RascheKumarGershneretal.2019, author = {Rasche, Leo and Kumar, Manoj and Gershner, Grant and Samant, Rohan and Van Hemert, Rudy and Heidemeier, Anke and Lapa, Constantin and Bley, Thorsten and Buck, Andreas and McDonald, James and Hillengass, Jens and Epstein, Joshua and Thanendrarajan, Sharmilan and Schinke, Carolina and van Rhee, Frits and Zangari, Maurizio and Barlogie, Bart and Davies, Faith E. and Morgan, Gareth J. and Weinhold, Niels}, title = {Lack of Spleen Signal on Diffusion Weighted MRI is associated with High Tumor Burden and Poor Prognosis in Multiple Myeloma: A Link to Extramedullary Hematopoiesis?}, series = {Theranostics}, volume = {9}, journal = {Theranostics}, number = {16}, doi = {10.7150/thno.33289}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224982}, pages = {4756-4763}, year = {2019}, abstract = {Due to the low frequency of abnormalities affecting the spleen, this organ is often overlooked during radiological examinations. Here, we report on the unexpected finding, that the spleen signal on diffusion-weighted MRI (DW-MRI) is associated with clinical parameters in patients with plasma cell dyscrasias. Methods: We investigated the spleen signal on DW-MRI together with clinical and molecular parameters in 295 transplant-eligible newly diagnosed Multiple Myeloma (NDMM) patients and in 72 cases with monoclonal gammopathy of undetermined significance (MGUS). Results: Usually, the spleen is the abdominal organ with the highest intensities on DW-MRI. Yet, significant signal loss on DW-MRI images was seen in 71 of 295 (24\%) NDMM patients. This phenomenon was associated with the level of bone marrow plasmacytosis (P=1x10(-10)) and International Staging System 3 (P=0.0001) but not with gain(1q), and del(17p) or plasma cell gene signatures. The signal was preserved in 72 individuals with monoclonal gammopathy of undetermined significance and generally re-appeared in MM patients responding to treatment, suggesting that lack of signal reflects increased tumor burden. While absence of spleen signal in MM patients with high risk disease defined a subgroup with very poor outcome, re-appearance of the spleen signal after autologous stem cell transplantation was seen in patients with improved outcome. Our preliminary observation suggests that extramedullary hematopoiesis in the spleen is a factor that modifies the DW-MRI signal of this organ. Conclusions: The DW-MRI spleen signal is a promising marker for tumor load and provides prognostic information in MM.}, language = {en} } @article{MatsusakaChenAriasLozaetal.2022, author = {Matsusaka, Yohji and Chen, Xinyu and Arias-Loza, Paula and Werner, Rudolf A. and Nose, Naoko and Sasaki, Takanori and Rowe, Steven P. and Pomper, Martin G. and Lapa, Constantin and Higuchi, Takahiro}, title = {In Vivo Functional Assessment of Sodium-Glucose Cotransporters (SGLTs) Using [\(^{18}\)F]Me4FDG PET in Rats}, series = {Molecular Imaging}, volume = {2022}, journal = {Molecular Imaging}, doi = {10.1155/2022/4635171}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300708}, year = {2022}, abstract = {Background. Mediating glucose absorption in the small intestine and renal clearance, sodium glucose cotransporters (SGLTs) have emerged as an attractive therapeutic target in diabetic patients. A substantial fraction of patients, however, only achieve inadequate glycemic control. Thus, we aimed to assess the potential of the SGLT-targeting PET radiotracer alpha-methyl-4-deoxy-4-[\(^{18}\)F]fluoro-D-glucopyranoside ([\(^{18}\)F]Me4FDG) as a noninvasive intestinal and renal biomarker of SGLT-mediated glucose transport. Methods. We investigated healthy rats using a dedicated small animal PET system. Dynamic imaging was conducted after administration of the reference radiotracer 2-deoxy-2-[\(^{18}\)F]fluoro-D-glucose ([\(^{18}\)F]FDG), or the SGLT-targeting agent, [\(^{18}\)F]Me4FDG either directly into the digestive tract (for assessing intestinal absorption) or via the tail vein (for evaluating kidney excretion). To confirm the specificity of [18F]Me4FDG and responsiveness to treatment, a subset of animals was also pretreated with the SGLT inhibitor phlorizin. In this regard, an intraintestinal route of administration was used to assess tracer absorption in the digestive tract, while for renal assessment, phlorizin was injected intravenously (IV). Results. Serving as reference, intestinal administration of [\(^{18}\)F]FDG led to slow absorption with retention of \% of administered radioactivity at 15 min. [\(^{18}\)F]Me4FDG, however, was rapidly absorbed into the blood and cleared from the intestine within 15 min, leading to markedly lower tracer retention of \% (). Intraintestinal phlorizin led to marked increase of [\(^{18}\)F]Me4FDG uptake (15 min, \%; vs. untreated controls), supporting the notion that this PET agent can measure adequate SGLT inhibition in the digestive tract. In the kidneys, radiotracer was also sensitive to SGLT inhibition. After IV injection, [\(^{18}\)F]Me4FDG reabsorption in the renal cortex was significantly suppressed by phlorizin when compared to untreated animals (\%ID/g at 60 min, vs. untreated controls, ; ). Conclusion. As a noninvasive read-out of the concurrent SGLT expression in both the digestive tract and the renal cortex, [\(^{18}\)F]Me4FDG PET may serve as a surrogate marker for treatment response to SGLT inhibition. As such, [\(^{18}\)F]Me4FDG may enable improvement in glycemic control in diabetes by PET-based monitoring strategies.}, 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{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{LapaSchrederSchirbeletal.2017, author = {Lapa, Constantin and Schreder, Martin and Schirbel, Andreas and Samnick, Samuel and Kort{\"u}m, Klaus Martin and Herrmann, Ken and Kropf, Saskia and Einsele, Herrmann and Buck, Andreas K. and Wester, Hans-J{\"u}rgen and Knop, Stefan and L{\"u}ckerath, Katharina}, title = {[\(^{68}\)Ga]Pentixafor-PET/CT for imaging of chemokine receptor CXCR4 expression in multiple myeloma - comparison to [\(^{18}\)F]FDG and laboratory values}, series = {Theranostics}, volume = {7}, journal = {Theranostics}, number = {1}, doi = {10.7150/thno.16576}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172106}, pages = {205-212}, year = {2017}, abstract = {Chemokine (C-X-C motif) receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer including multiple myeloma (MM). Proof-of-concept of CXCR4-directed radionuclide therapy in MM has recently been reported. This study assessed the diagnostic performance of the CXCR4-directed radiotracer [\(^{68}\)Ga]Pentixafor in MM and a potential role for stratifying patients to CXCR4-directed therapies. Thirty-five patients with MM underwent [\(^{68}\)Ga]Pentixafor-PET/CT for evaluation of eligibility for endoradiotherapy. In 19/35 cases, [\(^{18}\)F]FDG-PET/CT for correlation was available. Scans were compared on a patient and on a lesion basis. Tracer uptake was correlated with standard clinical parameters of disease activity. [\(^{68}\)Ga]Pentixafor-PET detected CXCR4-positive disease in 23/35 subjects (66\%). CXCR4-positivity at PET was independent from myeloma subtypes, cytogenetics or any serological parameters and turned out as a negative prognostic factor. In the 19 patients in whom a comparison to [\(^{18}\)F]FDG was available, [\(^{68}\)Ga]Pentixafor-PET detected more lesions in 4/19 (21\%) subjects, [\(^{18}\)F]FDG proved superior in 7/19 (37\%). In the remaining 8/19 (42\%) patients, both tracers detected an equal number of lesions. [\(^{18}\)F]FDG-PET positivity correlated with [\(^{68}\)Ga]Pentixafor-PET positivity (p=0.018). [\(^{68}\)Ga]Pentixafor-PET provides further evidence that CXCR4 expression frequently occurs in advanced multiple myeloma, representing a negative prognostic factor and a potential target for myeloma specific treatment. However, selecting patients for CXCR4 directed therapies and prognostic stratification seem to be more relevant clinical applications for this novel imaging modality, rather than diagnostic imaging of myeloma.}, language = {en} } @article{WernerWakabayashiBaueretal.2018, author = {Werner, Rudolf and Wakabayashi, Hiroshi and Bauer, Jochen and Sch{\"u}tz, Claudia and Zechmeister, Christina and Hayakawa, Nobuyuki and Javadi, Mehrbod S. and Lapa, Constantin and Jahns, Roland and Erg{\"u}n, S{\"u}leyman and Jahns, Valerie and Higuchi, Takahiro}, title = {Longitudinal \(^{18}\)F-FDG PET imaging in a Rat Model of Autoimmune Myocarditis}, series = {European Heart Journal Cardiovascular Imaging}, journal = {European Heart Journal Cardiovascular Imaging}, issn = {2047-2404}, doi = {10.1093/ehjci/jey119}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165601}, pages = {1-8}, year = {2018}, abstract = {Aims: Although mortality rate is very high, diagnosis of acute myocarditis remains challenging with conventional tests. We aimed to elucidate the potential role of longitudinal 2-Deoxy-2-\(^{18}\)F-fluoro-D-glucose (\(^{18}\)F-FDG) positron emission tomography (PET) inflammation monitoring in a rat model of experimental autoimmune myocarditis. Methods and results: Autoimmune myocarditis was induced in Lewis rats by immunizing with porcine cardiac myosin emulsified in complete Freund's adjuvant. Time course of disease was assessed by longitudinal \(^{18}\)F-FDG PET imaging. A correlative analysis between in- and ex vivo \(^{18}\)F-FDG signalling and macrophage infiltration using CD68 staining was conducted. Finally, immunohistochemistry analysis of the cell-adhesion markers CD34 and CD44 was performed at different disease stages determined by longitudinal \(^{18}\)F-FDG PET imaging. After immunization, myocarditis rats revealed a temporal increase in 18F-FDG uptake (peaked at week 3), which was followed by a rapid decline thereafter. Localization of CD68 positive cells was well correlated with in vivo \(^{18}\)F-FDG PET signalling (R\(^2\) = 0.92) as well as with ex vivo 18F-FDG autoradiography (R\(^2\) = 0.9, P < 0.001, respectively). CD44 positivity was primarily observed at tissue samples obtained at acute phase (i.e. at peak 18F-FDG uptake), while CD34-positive staining areas were predominantly identified in samples harvested at both sub-acute and chronic phases (i.e. at \(^{18}\)F-FDG decrease). Conclusion: \(^{18}\)F-FDG PET imaging can provide non-invasive serial monitoring of cardiac inflammation in a rat model of acute myocarditis.}, subject = {Myokarditis}, language = {en} } @article{WernerChenMayaetal.2018, author = {Werner, Rudolf A. and Chen, Xinyu and Maya, Yoshifumi and Eissler, Christoph and Hirano, Mitsuru and Nose, Naoko and Wakabayashi, Hiroshi and Lapa, Constantin and Javadi, Mehrbod S. and Higuchi, Takahiro}, title = {The Impact of Ageing on 11C-Hydroxyephedrine Uptake in the Rat Heart}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, number = {11120}, issn = {2281-5872}, doi = {10.1038/s41598-018-29509-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164826}, year = {2018}, abstract = {We aimed to explore the impact of ageing on 11C-Hydroxyephedrine (11C-HED) uptake in the healthy rat heart in a longitudinal setting. To investigate a potential cold mass effect, the influence of specific activity on cardiac 11C-HED uptake was evaluated: 11C-HED was synthesized by N-methylation of (-)-metaraminol as the free base (radiochemical purity >95\%) and a wide range of specific activities (0.2-141.9 GBq/μmol) were prepared. \(^{11}\)C-HED (48.7±9.7MBq, ranged 0.2-60.4μg/kg cold mass) was injected in healthy Wistar Rats. Dynamic 23-frame PET images were obtained over 30 min. Time activity curves were generated for the blood input function and myocardial tissue. Cardiac 11C-HED retention index (\%/min) was calculated as myocardial tissue activity at 20-30 min divided by the integral of the blood activity curves. Additionally, the impact of ageing on myocardial 11CHED uptake was investigated longitudinally by PET studies at different ages of healthy Wistar Rats. A dose-dependent reduction of cardiac 11C-HED uptake was observed: The estimated retention index as a marker of norepinephrine function decreased at a lower specific activity (higher amount of cold mass). This observed high affinity of 11C-HED to the neural norepinephrine transporter triggered a subsequent study: In a longitudinal setting, the 11C-HED retention index decreased with increasing age. An age-related decline of cardiac sympathetic innervation could be demonstrated. The herein observed cold mass effect might increase in succeeding scans and therefore, 11C-HED microPET studies should be planned with extreme caution if one single radiosynthesis is scheduled for multiple animals.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{WernerSheikhbahaeiJonesetal.2017, author = {Werner, Rudolf A. and Sheikhbahaei, Sara and Jones, Krystyna M. and Javadi, Mehrbod S. and Solnes, Lilja B. and Ross, Ashley E. and Allaf, Mohamad E. and Pienta, Kenneth J. and Lapa, Constantin and Buck, Andreas K. and Higuchi, Takahiro and Pomper, Martin G. and Gorin, Micheal A. and Rowe, Steven P.}, title = {Patterns of uptake of prostate-specific membrane antigen (PSMA)-targeted \(^{18}\)F-DCFPyL in peripheral ganglia}, series = {Annals of Nuclear Medicine}, volume = {31}, journal = {Annals of Nuclear Medicine}, number = {9}, issn = {0914-7187}, doi = {10.1007/s12149-017-1201-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166971}, pages = {696-702}, year = {2017}, abstract = {Objective: Radiotracers targeting prostate-specific membrane antigen (PSMA) have increasingly been recognized as showing uptake in a number of normal structures, anatomic variants, and non-prostate-cancer pathologies. We aimed to explore the frequency and degree of uptake in peripheral ganglia in patients undergoing PET with the PSMA-targeted agent \(^{18}\)F-DCFPyL. Methods: A total of 98 patients who underwent \(^{18}\)F-DCFPyL PET/CT imaging were retrospectively analyzed. This included 76 men with prostate cancer (PCa) and 22 patients with renal cell carcinoma (RCC; 13 men, 9 women). Scans were evaluated for uptake in the cervical, stellate, celiac, lumbar and sacral ganglia. Maximum standardized uptake value corrected to body weight (SUV\(_{max}\)), and maximum standardized uptake value corrected to lean body mass (SUL\(_{max}\)) were recorded for all ganglia with visible uptake above background. Ganglia-to-background ratios were calculated by dividing the SUV\(_{max}\) and SUL\(_{max}\) values by the mean uptake in the ascending aorta (Aortamean) and the right gluteus muscle (Gluteusmean). Results: Overall, 95 of 98 (96.9\%) patients demonstrated uptake in at least one of the evaluated peripheral ganglia. With regard to the PCa cohort, the most frequent sites of radiotracer accumulation were lumbar ganglia (55/76, 72.4\%), followed by the cervical ganglia (51/76, 67.1\%). Bilateral uptake was found in the majority of cases [lumbar 44/55 (80\%) and cervical 30/51 (58.8\%)]. Additionally, discernible radiotracer uptake was recorded in 50/76 (65.8\%) of the analyzed stellate ganglia and in 45/76 (59.2\%) of the celiac ganglia, whereas only 5/76 (6.6\%) of the sacral ganglia demonstrated \(^{18}\)F-DCFPyL accumulation. Similar findings were observed for patients with RCC, with the most frequent locations of radiotracer uptake in both the lumbar (20/22, 90.9\%) and cervical ganglia (19/ 22, 86.4\%). No laterality preference was found in mean PSMA-ligand uptake for either the PCa or RCC cohorts. Conclusion: As PSMA-targeted agents become more widely disseminated, the patterns of uptake in structures that are not directly relevant to patients' cancers must be understood. This is the first systematic evaluation of the uptake of \(^{18}\)F-DCFPyL in ganglia demonstrating a general trend with a descending frequency of radiotracer accumulation in lumbar, cervical, stellate, celiac, and sacral ganglia. The underlying biology that leads to variability of PSMA-targeted radiotracers in peripheral ganglia is not currently understood, but may provide opportunities for future research.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @unpublished{WernerAndreeJavadietal.2018, author = {Werner, Rudolf A. and Andree, Christian and Javadi, Mehrbod S. and Lapa, Constantin and Buck, Andreas K. and Higuchi, Takahiro and Pomper, Martin G. and Gorin, Michael A. and Rowe, Steven P. and Pienta, Kenneth J.}, title = {A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging}, series = {Urology - The Gold Journal}, journal = {Urology - The Gold Journal}, issn = {0090-4295}, doi = {10.1016/j.urology.2018.03.030}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161103}, year = {2018}, abstract = {No abstract available.}, subject = {Virchow Node}, language = {en} } @article{WernerAndreeJavadietal.2018, author = {Werner, Rudolf A. and Andree, Christian and Javadi, Mehrbod S. and Lapa, Constantin and Buck, Andreas K. and Higuchi, Takahiro and Pomper, Martin G. and Gorin, Michael A. and Rowe, Steven P. and Pienta, Kenneth J.}, title = {A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging}, series = {Urology - The Gold Journal}, volume = {117}, journal = {Urology - The Gold Journal}, issn = {0090-4295}, doi = {10.1016/j.urology.2018.03.030}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164632}, pages = {18-21}, year = {2018}, abstract = {No abstract available.}, 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{ChenWernerJavadietal.2015, author = {Chen, Xinyu and Werner, Rudolf A. and Javadi, Mehrbod S. and Maya, Yoshifumi and Decker, Michael and Lapa, Constantin and Herrmann, Ken and Higuchi, Takahiro}, title = {Radionuclide imaging of neurohormonal system of the heart}, series = {Theranostics}, volume = {5}, journal = {Theranostics}, number = {6}, doi = {10.7150/thno.10900}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149205}, pages = {545-558}, year = {2015}, abstract = {Heart failure is one of the growing causes of death especially in developed countries due to longer life expectancy. Although many pharmacological and instrumental therapeutic approaches have been introduced for prevention and treatment of heart failure, there are still limitations and challenges. Nuclear cardiology has experienced rapid growth in the last few decades, in particular the application of single photon emission computed tomography (SPECT) and positron emission tomography (PET), which allow non-invasive functional assessment of cardiac condition including neurohormonal systems involved in heart failure; its application has dramatically improved the capacity for fundamental research and clinical diagnosis. In this article, we review the current status of applying radionuclide technology in non-invasive imaging of neurohormonal system in the heart, especially focusing on the tracers that are currently available. A short discussion about disadvantages and perspectives is also included.}, language = {en} } @article{WernerChenRoweetal.2018, author = {Werner, Rudolf A. and Chen, Xinyu and Rowe, Steven P. and Lapa, Constantin and Javadi, Mehrbod S. and Higuchi, Takahiro}, title = {Moving into the Next Era of PET Myocardial Perfusion Imaging - Introduction of Novel \(^{18}\)F-labeled Tracers}, series = {The International Journal of Cardiovascular Imaging}, journal = {The International Journal of Cardiovascular Imaging}, issn = {1569-5794}, doi = {10.1007/s10554-018-1469-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169134}, year = {2018}, abstract = {The heart failure (HF) epidemic continues to rise with coronary artery disease (CAD) as one of its main causes. Novel concepts for risk stratification to guide the referring cardiologist towards revascularization procedures are of significant value. Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) agents has demonstrated high accuracy for the detection of clinically relevant stenoses. With positron emission tomography (PET) becoming more widely available, mainly due to its diagnostic performance in oncology, perfusion imaging with that modality is more practical than in the past and overcomes existing limitations of SPECT MPI. Advantages of PET include more reliable quantification of absolute myocardial blood flow, the routine use of computed tomography for attenuation correction, a higher spatiotemporal resolution and a higher count sensitivity. Current PET radiotracers such as rubidium-82 (half-life, 76 sec), oxygen-15 water (2 min) or nitrogen-13 ammonia (10 min) are labeled with radionuclides with very short half-lives, necessitating that stress imaging is performed under pharmacological vasodilator stress instead of exercise testing. However, with the introduction of novel 18F-labeled MPI PET radiotracers (half-life, 110 min), the intrinsic advantages of PET can be combined with exercise testing. Additional advantages of those radiotracers include, but are not limited to: potentially improved cost-effectiveness due to the use of pre-existing delivery systems and superior imaging qualities, mainly due to the shortest positron range among available PET MPI probes. In the present review, widely used PET MPI radiotracers will be reviewed and potential novel 18F-labeled perfusion radiotracers will be discussed.}, subject = {Positronenemissionstomografie}, language = {en} } @article{WernerIlhanLehneretal.2018, author = {Werner, Rudolf A. and Ilhan, Harun and Lehner, Sebastian and Papp, L{\´a}szl{\´o} and Zs{\´o}t{\´e}r, Norbert and Schatka, Imke and Muegge, Dirk O. and Javadi, Mehrbod S. and Higuchi, Takahiro and Buck, Andreas K. and Bartenstein, Peter and Bengel, Frank and Essler, Markus and Lapa, Constantin and Bundschuh, Ralph A.}, title = {Pre-therapy Somatostatin-Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy}, series = {Molecular Imaging and Biology}, journal = {Molecular Imaging and Biology}, issn = {1536-1632}, doi = {10.1007/s11307-018-1252-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167168}, year = {2018}, abstract = {Purpose: Early identification of aggressive disease could improve decision-support in pancreatic neuroendocrine tumor (pNET) patients prior to peptide receptor radionuclide therapy (PRRT). The prognostic value of intratumoral textural features (TF) determined by baseline somatostatin receptor (SSTR)-PET before PRRT was analyzed. Procedures: 31 patients with G1/G2 pNET were enrolled (G2, n=23/31). Prior to PRRT with [\(^{177}\)Lu]DOTATATE (mean, 3.6 cycles), baseline SSTR-PET/CT was performed. By segmentation of 162 (median per patient, 5) metastases, intratumoral TF were computed. The impact of conventional PET parameters (SUV\(_{mean/max}\)), imaging-based TF as well as clinical parameters (Ki67, CgA) for prediction of both progression-free (PFS) and overall survival (OS) after PRRT was evaluated. Results: Within a median follow-up of 3.7y, tumor progression was detected in 21 patients (median, 1.5y) and 13/31 deceased (median, 1.9y). In ROC analysis, the TF Entropy, reflecting derangement on a voxel-by-voxel level, demonstrated predictive capability for OS (cutoff=6.7, AUC=0.71, p=0.02). Of note, increasing Entropy could predict a longer survival (>6.7, OS=2.5y, 17/31), whereas less voxel-based derangement portended inferior outcome (<6.7, OS=1.9y, 14/31). These findings were supported in a G2 subanalysis (>6.9, OS=2.8y, 9/23 vs. <6.9, OS=1.9y, 14/23). Kaplan-Meier analysis revealed a significant distinction between high- and low-risk groups using Entropy (n=31, p<0.05). For those patients below the ROC-derived threshold, the relative risk of death after PRRT was 2.73 (n=31, p=0.04). Ki67 was negatively associated with PFS (p=0.002); however, SUVmean/max failed in prognostication (n.s.). Conclusions: In contrast to conventional PET parameters, assessment of intratumoral heterogeneity demonstrated superior prognostic performance in pNET patients undergoing PRRT. This novel PET-based strategy of outcome prediction prior to PRRT might be useful for patient risk stratification.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{WernerBundschuhBundschuhetal.2018, author = {Werner, Rudolf A. and Bundschuh, Ralph A. and Bundschuh, Lena and Javadi, Mehrbod S. and Higuchi, Takahiro and Weich, Alexander and Sheikhbahaei, Sara and Pienta, Kenneth J. and Buck, Andreas K. and Pomper, Martin G. and Gorin, Michael A. and Lapa, Constantin and Rowe, Steven P.}, title = {MI-RADS: Molecular Imaging Reporting and Data Systems - A Generalizable Framework for Targeted Radiotracers with Theranostic Implications}, series = {Annals of Nuclear Medicine}, journal = {Annals of Nuclear Medicine}, issn = {0914-7187}, doi = {10.1007/s12149-018-1291-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166995}, year = {2018}, abstract = {Both prostate-specific membrane antigen (PSMA)- and somatostatin receptor (SSTR)-targeted positron emission tomography (PET) imaging agents for staging and restaging of prostate carcinoma or neuroendocrine tumors, respectively, are seeing rapidly expanding use. In addition to diagnostic applications, both classes of radiotracers can be used to triage patients for theranostic endoradiotherapy. While interpreting PSMA- or SSTR-targeted PET/computed tomography (CT) scans, the reader has to be aware of certain pitfalls. Adding to the complexity of the interpretation of those imaging agents, both normal biodistribution, and also false-positive and -negative findings differ between PSMA- and SSTR-targeted PET radiotracers. Herein summarized under the umbrella term molecular imaging reporting and data systems (MI-RADS), two novel RADS classifications for PSMA- and SSTR-targeted PET imaging are described (PSMA- and SSTR-RADS). Both framework systems may contribute to increase the level of a reader's confidence and to navigate the imaging interpreter through indeterminate lesions, so that appropriate workup for equivocal findings can be pursued. Notably, PSMA- and SSTR-RADS are structured in a reciprocal fashion, i.e. if the reader is familiar with one system, the other system can readily be applied as well. In the present review we will discuss the most common pitfalls on PSMA- and SSTR-targeted PET/CT, briefly introduce PSMA- and SSTR-RADS, and define a future role of the umbrella framework MI-RADS compared to other harmonization systems.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{WernerBundschuhHiguchietal.2018, author = {Werner, Rudolf A. and Bundschuh, Ralph A. and Higuchi, Takahiro and Javadi, Mehrbod S. and Rowe, Steven P. and Zs{\´o}t{\´e}r, Norbert and Kroiss, Matthias and Fassnacht, Martin and Buck, Andreas K. and Kreissl, Michael C. and Lapa, Constantin}, title = {Volumetric and Texture Analysis of Pretherapeutic \(^{18}\)F-FDG PET can Predict Overall Survival in Medullary Thyroid Cancer Patients Treated with Vandetanib}, series = {Endocrine}, journal = {Endocrine}, issn = {1355-008X}, doi = {10.1007/s12020-018-1749-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167910}, year = {2018}, abstract = {Purpose: The metabolically most active lesion in 2-deoxy-2-(\(^{18}\)F)fluoro-D-glucose (\(^{18}\)F-FDG) PET/CT can predict progression-free survival (PFS) in patients with medullary thyroid carcinoma (MTC) starting treatment with the tyrosine kinase inhibitor (TKI) vandetanib. However, this metric failed in overall survival (OS) prediction. In the present proof of concept study, we aimed to explore the prognostic value of intratumoral textural features (TF) as well as volumetric parameters (total lesion glycolysis, TLG) derived by pre-therapeutic \(^{18}\)F-FDG PET. Methods: Eighteen patients with progressive MTC underwent baseline \(^{18}\)F-FDG PET/CT prior to and 3 months after vandetanib initiation. By manual segmentation of the tumor burden at baseline and follow-up PET, intratumoral TF and TLG were computed. The ability of TLG, imaging-based TF, and clinical parameters (including age, tumor marker doubling times, prior therapies and RET (rearranged during transfection) mutational status) for prediction of both PFS and OS were evaluated. Results: The TF Complexity and the volumetric parameter TLG obtained at baseline prior to TKI initiation successfully differentiated between low- and high-risk patients. Complexity allocated 10/18 patients to the high-risk group with an OS of 3.3y (vs. low-risk group, OS=5.3y, 8/18, AUC=0.78, P=0.03). Baseline TLG designated 11/18 patients to the high-risk group (OS=3.5y vs. low-risk group, OS=5y, 7/18, AUC=0.83, P=0.005). The Hazard Ratio for cancer-related death was 6.1 for Complexity (TLG, 9.5). Among investigated clinical parameters, the age at initiation of TKI treatment reached significance for PFS prediction (P=0.02, OS, n.s.). Conclusions: The TF Complexity and the volumetric parameter TLG are both independent parameters for OS prediction.}, subject = {Positronen-Emissions-Tomografie}, language = {en} } @article{WernerEisslerHayakawaetal.2018, author = {Werner, Rudolf A. and Eissler, Christoph and Hayakawa, Nobuyuki and Arias-Loza, Paula and Wakabayashi, Hiroshi and Javadi, Mehrbod S. and Chen, Xinyu and Shinaji, Tetsuya and Lapa, Constantin and Pelzer, Theo and Higuchi, Takahiro}, title = {Left Ventricular Diastolic Dysfunction in a Rat Model of Diabetic Cardiomyopathy using ECG-gated \(^{18}\)F-FDG PET}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, number = {17631}, doi = {10.1038/s41598-018-35986-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171765}, year = {2018}, abstract = {In diabetic cardiomyopathy, left ventricular (LV) diastolic dysfunction is one of the earliest signs of cardiac involvement prior to the definitive development of heart failure (HF). We aimed to explore the LV diastolic function using electrocardiography (ECG)-gated \(^{18}\)F-fluorodeoxyglucose positron emission tomography (\(^{18}\)F-FDG PET) imaging beyond the assessment of cardiac glucose utilization in a diabetic rat model. ECG-gated \(^{18}\)F-FDG PET imaging was performed in a rat model of type 2 diabetes (ZDF fa/fa) and ZL control rats at age of 13 weeks (n=6, respectively). Under hyperinsulinemic-euglycemic clamp to enhance cardiac activity, \(^{18}\)F-FDG was administered and subsequently, list-mode imaging using a dedicated small animal PET system with ECG signal recording was performed. List-mode data were sorted and reconstructed into tomographic images of 16 frames per cardiac cycle. Left ventricular functional parameters (systolic: LV ejection fraction (EF), heart rate (HR) vs. diastolic: peak filling rate (PFR)) were obtained using an automatic ventricular edge detection software. No significant difference in systolic function could be obtained (ZL controls vs. ZDF rats: LVEF, 62.5±4.2 vs. 59.4±4.5\%; HR: 331±35 vs. 309±24 bpm; n.s., respectively). On the contrary, ECG-gated PET imaging showed a mild but significant decrease of PFR in the diabetic rats (ZL controls vs. ZDF rats: 12.1±0.8 vs. 10.2±1 Enddiastolic Volume/sec, P<0.01). Investigating a diabetic rat model, ECG-gated \(^{18}\)F-FDG PET imaging detected LV diastolic dysfunction while systolic function was still preserved. This might open avenues for an early detection of HF onset in high-risk type 2 diabetes before cardiac symptoms become apparent.}, language = {en} } @article{WernerWeichKircheretal.2018, author = {Werner, Rudolf A. and Weich, Alexander and Kircher, Malte and Solnes, Lilja B. and Javadi, Mehrbod S. and Higuchi, Takahiro and Buck, Andreas K. and Pomper, Martin G. and Rowe, Steven and Lapa, Constantin}, title = {The theranostic promise for neuroendocrine tumors in the late 2010s - Where do we stand, where do we go?}, series = {Theranostics}, volume = {8}, journal = {Theranostics}, number = {22}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170264}, pages = {6088-6100}, year = {2018}, abstract = {More than 25 years after the first peptide receptor radionuclide therapy (PRRT), the concept of somatostatin receptor (SSTR)-directed imaging and therapy for neuroendocrine tumors (NET) is seeing rapidly increasing use. To maximize the full potential of its theranostic promise, efforts in recent years have expanded recommendations in current guidelines and included the evaluation of novel theranostic radiotracers for imaging and treatment of NET. Moreover, the introduction of standardized reporting framework systems may harmonize PET reading, address pitfalls in interpreting SSTR-PET/CT scans and guide the treating physician in selecting PRRT candidates. Notably, the concept of PRRT has also been applied beyond oncology, e.g. for treatment of inflammatory conditions like sarcoidosis. Future perspectives may include the efficacy evaluation of PRRT compared to other common treatment options for NET, novel strategies for closer monitoring of potential side effects, the introduction of novel radiotracers with beneficial pharmacodynamic and kinetic properties or the use of supervised machine learning approaches for outcome prediction. This article reviews how the SSTR-directed theranostic concept is currently applied and also reflects on recent developments that hold promise for the future of theranostics in this context.}, subject = {Positronen-Emissions-Tomografie}, language = {en} }