68Ga-PSMA-HBED-CC PET/CT detects location and extent of primary prostate cancer.

We evaluated the accuracy of (68)Ga-PSMA-HBED-CC ((68)Ga-PSMA) positron emission tomography/computed tomography (PET/CT) to localize cancer in the prostate and surrounding tissue at initial diagnosis.

Twenty-one patients with biopsy-proven prostate cancer (PCa) underwent (68)Ga-PSMA PET/CT at a median of 4 (range: 0 to 47) days prior to radical prostatectomy. Based on a 6-segment model, the Gleason score (GS) and segmental tumor burden (STBHP) as determined by histopathology were correlated with maximum standardized uptake value (SUVmax) and tumor burden as determined by different SUV cut-off values for (68)Ga-PSMA PET (STBPET1-6). Furthermore, the involvement of seminal vesicles and other extracapsular extension were assessed by histopathology and PET/CT.

Histopathology positive (+) segments (n = 100 of 126, 79%) demonstrated a significantly higher mean±standard deviation (SD) SUVmax (11.8±7.6) as compared to histopathology negative (-) segments (4.9±2.9; p<0.001). Receiver-operating-characteristic revealed an optimal SUVmax cut-off value of 6.5 for discrimination of histopathology+/- segments (area under the curve, AUC: 0.84; p<0.001) which gave 67% sensitivity, 92% specificity, 97% positive predictive value, 42% negative predictive value, and 72% accuracy. STBPET3 as determined by 2xSUVblood+2xSD correlated best with STBHP (Pearson's rho=0.68; p<0.001; mean difference±SD = 19±15%). PET/CT correctly detected invasion of seminal vesicles (n = 11 of 21 patients; 52%) with 86% accuracy, and tumor spread through the capsule (n = 12; 57%) with 71% accuracy.

(68)Ga-PSMA PET/CT accurately detects location and extent of primary prostate cancer. Our preliminary findings warrant further investigation of (68)Ga-PSMA PET/CT in conjunction with needle biopsy.

Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2016 Jun 03 [Epub ahead of print]

Wolfgang P Fendler, Dorothea F Schmidt, Vera Wenter, Kolja M Thierfelder, Christian Zach, Christian Stief, Peter Bartenstein, Thomas Kirchner, Franz J Gildehaus, Christian Gratzke, Claudius Faber

Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany, Germany;, Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany, Germany;, Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany, Germany;, Institute for Clinical Radiology, Ludwig-Maximilians-University of Munich, Munich, Germany;, Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany, Germany;, Department of Urology, Ludwig-Maximilians-University of Munich, Munich, Germany;, Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany, Germany;, Institute of Pathology, Ludwig-Maximilians-University of Munich, Munich, Germany., Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany, Germany;, Department of Urology, Ludwig-Maximilians-University of Munich, Munich, Germany;, Institute of Pathology, Ludwig-Maximilians-University of Munich, Munich, Germany.