TY - CHAP A1 - Werner, Rudolf A1 - Hayakawa, Nobuyuki A1 - Arias-Loza, Paula-Anah A1 - Wakabayashi, Hiroshi A1 - Shinaji, Tetsuya A1 - Lapa, Constantin A1 - Pelzer, Theo A1 - Higuchi, Takahiro T1 - Bildgebung der frühen linksventrikulären Dysfunktion mit ECG-gated F-18-FDG PET in einem Diabetes-Ratten-Modell T2 - Nuklearmedizin N2 - Einleitung: Die linksventrikuläre 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 über 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 linksventrikuläre Ejektionsfraktion (EF) und die Peak Füllrate (PFR) wurden mittels einer geeigneten Software (Heart Function View) gemessen, wobei die Software an die Größe des Rattenherzes angepasst wurde. Ergebnisse: Im Alter von 13 Wochen entwickeln ZDF Diabetes-Ratten eine im Vergleich zu Kontrolltieren eine signifikante myokardiale Hypertrophie, bestätigt 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 frühen diabetischen Kardiomyopathie nachgewiesen werden. KW - Positronen-Emissions-Tomografie KW - Diabetes KW - diabetische Kardiomyopathie KW - Positronen-Emissions-Tomografie KW - PET KW - EKG KW - ECG KW - ECG-gated Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161396 UR - http://www.nuklearmedizin.de/jahrestagungen/abstr_online2017/print_abstract_pdf.php SN - 0029-5566 N1 - This article is not an exact copy of the original published article in Nuklearmedizin. The definitive publisher-authenticated version of „Bildgebung der frühen linksventrikulären Dysfunktion mit ECG-gated F-18-FDG PET in einem Diabetes-Ratten-Modell. Nuklearmedizin 2017; 56 (Abstract Nr.: V119).“ is available online at http://www.nuklearmedizin.de/jahrestagungen/abstr_online2017/print_abstract_pdf.php VL - 56 IS - 2 PB - Schattauer Verlag ER - TY - JOUR A1 - Werner, Rudolf A1 - Schmid, Jan-Stefan A1 - Higuchi, Takahiro A1 - Javadi, Mehrbod S. A1 - Rowe, Steven P. A1 - Märkl, Bruno A1 - Aulmann, Christoph A1 - Fassnacht, Martin A1 - Kroiß, Matthias A1 - Reiners, Christoph A1 - Buck, Andreas A1 - Kreissl, Michael A1 - Lapa, Constantin T1 - Predictive value of \(^{18}\)F-FDG PET in patients with advanced medullary thyroid carcinoma treated with vandetanib JF - Journal of Nuclear Medicine N2 - 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. KW - positron emission tomography KW - Medullärer Schilddrüsenkrebs KW - Positronen-Emissions-Tomografie KW - medullary thyroid carcinoma KW - tyrosine kinase inhibitor KW - vandetanib KW - 2- deoxy-2-(18F)fluoro-D-glucose KW - 18F-FDG Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161256 SN - 0161-5505 N1 - This research was originally published in JNM. Rudolf A. Werner, Jan-Stefan Schmid, Takahiro Higuchi, Mehrbod S. Javadi, Steven P. Rowe, Bruno Märkl, Christoph Aulmann, Martin Fassnacht, Matthias Kroiss, Christoph Reiners, Andreas K. Buck, Michael C. Kreissl, Constantin Lapa. Predictive value of 18F-FDG PET in patients with advanced medullary thyroid carcinoma treated with vandetanib. J Nucl Med. May 1, 2018;vol. 59 no. 5: 756-761. © SNMMI. ER - TY - JOUR A1 - Werner, Rudolf A1 - Wakabyashi, Hiroshi A1 - Chen, Xinyu A1 - Hirano, Mitsuru A1 - Shinaji, Tetsuya A1 - Lapa, Constantin A1 - Rowe, Steven A1 - Javadi, Mehrbod A1 - Higuchi, Takahiro T1 - Functional renal imaging with \(^{18}\)F-FDS PET in rat models of renal disorders JF - Journal of Nuclear Medicine N2 - 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. KW - unilateral ureteral obstruction KW - Nierenfunktionsstörung KW - Positronen-Emissions-Tomografie KW - 18F-FDS KW - 99mTc-DTPA KW - PET KW - renal failure KW - Glomerular filtration Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161279 SN - 0161-5505 N1 - This research was originally published in JNM. Rudolf A. Werner, Hiroshi Wakabayashi, Xinyu Chen, Mitsuru Hirano, Tetsuya Shinaji, Constantin Lapa, Steven P. Rowe, Mehrbod S. Javadi and Takahiro Higuchi. Functional renal imaging with 18F-FDS PET in rat models of renal disorders. J Nucl Med. May 1, 2018;vol. 59 no. 5: 828-832. © SNMMI. ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Kobayashi, Ryohei A1 - Javadi, Mehrbod Som A1 - Köck, Zoe A1 - Wakabayashi, Hiroshi A1 - Unterecker, Stefan A1 - Nakajima, Kenichi A1 - Lapa, Constantin A1 - Menke, Andreas A1 - Higuchi, Takahiro T1 - Impact of Novel Antidepressants on Cardiac Metaiodobenzylguanidine (mIBG) Uptake: Experimental Studies in SK-N-SH Cells and Healthy Rabbits JF - Journal of Nuclear Medicine N2 - 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. KW - MDD KW - Antidepressants KW - depression KW - 123I-mIBG KW - antidepressant KW - cardiac sympathetic nerve system KW - major depressive disorder KW - myocardial sympathetic innervation imaging Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161280 SN - 0161-5505 N1 - This research was originally published in JNM. Rudolf A. Werner, Ryohei Kobayashi, Mehrbod Som Javadi, Zoe Köck, Hiroshi Wakabayashi, Stefan Unterecker, Kenichi Nakajima, Constantin Lapa, Andreas Menke, Takahiro Higuchi. Impact of Novel Antidepressants on Cardiac Metaiodobenzylguanidine (mIBG) Uptake: Experimental Studies in SK-N-SH Cells and Healthy Rabbits. J. Nucl. Med. July 1, 2018, vol. 59, no. 7, 1099-1103. © SNMMI. ER - TY - JOUR A1 - Werner, Rudolf A1 - Solnes, Lilja A1 - Javadi, Mehrbod A1 - Weich, Alexander A1 - Gorin, Michael A1 - Pienta, Kenneth A1 - Higuchi, Takahiro A1 - Buck, Andreas A1 - Pomper, Martin A1 - Rowe, Steven A1 - Lapa, Constantin T1 - SSTR-RADS Version 1.0 as a Reporting System for SSTR-PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework JF - Journal of Nuclear Medicine N2 - 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. KW - Radionuclide Therapy KW - Standardisierung KW - Positronen-Emissions-Tomografie KW - 68Ga-DOTATATE/-TOC KW - Gastrointestinal KW - Neuroendocrine KW - Neuroendocrine Tumor KW - Oncology KW - GI KW - PET KW - PET/CT KW - PRRT KW - RADS KW - SSTR Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161298 SN - 0161-5505 N1 - This research was originally published in JNM. Rudolf A. Werner, Lilja B. Solnes, Mehrbod Som Javadi, Alexander Weich, Michael A. Gorin, Kenneth J. Pienta, Takahiro Higuchi, Andreas K. Buck, Martin G. Pomper, Steven P. Rowe, Constantin Lapa. SSTR-RADS Version 1.0 as a Reporting System for SSTR-PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework. J. Nucl. Med. July 1, 2018, vol. 59, no. 7, 1085-1091. © SNMMI ER - TY - CHAP A1 - Werner, Rudolf A. A1 - Marcus, Charles A1 - Sheikhbahaei, Sara A1 - Higuchi, Takahiro A1 - Solnes, Lilja B. A1 - Rowe, Steven P. A1 - Buck, Andreas K. A1 - Lapa, Constantin A1 - Javadi, Mehrbod S. T1 - Diagnostic Accuracy of Visual Assessment of an Initial DaT-Scan in Comparison to a Fully Automatic Semiquantitative Method T2 - Journal of Nuclear Medicine N2 - No abstract available. KW - Parkinson-Krankheit KW - SPECT KW - Parkinson KW - Parkinson Disease KW - DaTscan KW - Ioflupane KW - molecular imaging Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162208 UR - http://jnm.snmjournals.org/content/59/supplement_1/626.abstract SN - 0161-5505 N1 - This research was originally published in JNM. Rudolf A. Werner, Charles Marcus, Sara Sheikhbahaei, Takahiro Higuchi, Lilja B. Solnes, Steven P. Rowe, Andreas K. Buck, Constantin Lapa, Mehrbod S. Javadi. Diagnostic Accuracy of Visual Assessment of an Initial DaT-Scan in Comparison to a Fully Automatic Semiquantitative Method. J Nucl Med. May 1, 2018; vol. 59 no. supplement 1:626. © SNMMI. VL - 59 IS - Supplement No. 1 SP - 626 ER - TY - CHAP A1 - Werner, Rudolf A. A1 - Marcus, Charles A1 - Sheikhbahaei, Sara A1 - Higuchi, Takahiro A1 - Solnes, Lilja B. A1 - Rowe, Steven P. A1 - Buck, Andreas K. A1 - Lapa, Constantin A1 - Javadi, Mehrbod S. T1 - The Impact of Ageing on Dopamine Transporter Imaging T2 - Journal of Nuclear Medicine N2 - No abstract available. KW - Parkinson-Krankheit KW - Parkinson KW - Parkinson Disease KW - DaTscan KW - Ioflupane KW - SPECT KW - molecular imaging KW - ageing Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162213 UR - http://jnm.snmjournals.org/content/59/supplement_1/1646.abstract SN - 0161-5505 N1 - This research was originally published in JNM. Rudolf A. Werner, Charles Marcus, Sara Sheikhbahaei, Takahiro Higuchi, Lilja B. Solnes, Steven P. Rowe, Andreas K. Buck, Constantin Lapa, Mehrbod S. Javadi. The Impact of Ageing on Dopamine Transporter Imaging. J Nucl Med. May 1, 2018; vol. 59 no. supplement 1:1646. © SNMMI. VL - 59 IS - Supplement No 1 SP - 1646 ER - TY - CHAP A1 - Werner, Rudolf A. A1 - Chen, Xinyu A1 - Hirano, Mitsuru A1 - Nose, Naoko A1 - Lapa, Constantin A1 - Javadi, Mehrbod S. A1 - Higuchi, Takahiro T1 - The Impact of Ageing on [\(^{11}\)C]meta-Hydroxyephedrine Uptake in the Rat Heart T2 - Journal of Nuclear Medicine N2 - No abstract available. KW - Positronen-Emissions-Tomografie KW - moycardial sympathetic innervation KW - Positronen-Emissions-Tomografie KW - positron emission tomography KW - PET KW - 11C-HED KW - hydroxyephedrine KW - ageing Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162228 UR - http://jnm.snmjournals.org/content/59/supplement_1/100.abstract SN - 0161-5505 VL - 59 IS - Supplement No 1 ER - TY - JOUR A1 - Lapa, Constantin A1 - Arias-Loza, Paula A1 - Hayakawa, Nobuyuki A1 - Wakabayashi, Hiroshi A1 - Werner, Rudolf A. A1 - Chen, Xinyu A1 - Shinaji, Tetsuya A1 - Herrmann, Ken A1 - Pelzer, Theo A1 - Higuchi, Takahiro T1 - Whitening and impaired glucose utilization of brown adipose tissue in a rat model of type 2 diabetes mellitus JF - Scientific Reports N2 - 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. KW - molecular medicine KW - endocrinology Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159066 VL - 7 ER - TY - INPR A1 - Werner, Rudolf A. A1 - Ilhan, Harun A1 - Lehner, Sebastian A1 - Papp, László A1 - Zsótér, Norbert A1 - Schatka, Imke A1 - Muegge, Dirk O. A1 - Javadi, Mehrbod S. A1 - Higuchi, Takahiro A1 - Buck, Andreas K. A1 - Bartenstein, Peter A1 - Bengel, Frank A1 - Essler, Markus A1 - Lapa, Constantin A1 - Bundschuh, Ralph A. T1 - Pre-therapy Somatostatin-Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy T2 - Molecular Imaging and Biology N2 - 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. KW - Pancreas KW - Positronen-Emissions-Tomografie KW - PET KW - neuroendocrine tumor KW - tumor heterogeneity KW - [68Ga] KW - [177Lu]-DOTATATE/-DOTATOC KW - PET/CT KW - SSTR Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164624 UR - https://link.springer.com/article/10.1007/s11307-018-1252-5 SN - 1536-1632 N1 - This is a post-peer-review, pre-copyedit version of an article published in Molecular Imaging and Biology. The final authenticated version is available online at: http://dx.doi.org/s11307-018-1252-5 N1 - Die finale Version dieses Artikels steht unter https://doi.org/10.1007/s11307-018-1252-5 bzw. http://nbn-resolving.org/urn:nbn:de:bvb:20-opus-167168 open access zur Verfügung. ER -