68Ga-PSMA-11 positron-emission tomography/computed tomography (PET/CT) is commonly used for restaging recurrent prostate cancer (PC) in European clinical practice. The goal of this study is to determine the optimum time for performing these PET/CT scans in a large cohort of patients by identifying the prostate-specific-antigen (PSA) and PSA kinetics thresholds for detecting and localizing recurrent PC. This retrospective analysis includes 581 patients with biochemical recurrence (BC) by definition. The performance of 68Ga-PSMA-11 PET/CT in relation to the PSA value at the scan time as well as PSA kinetics was assessed by the receiver-operating-characteristic-curve (ROC) generated by plotting sensitivity versus 1-specificity. Malignant prostatic lesions were identified in 77%. For patients that were treated with radical prostatectomy (RP) a PSA value of 1.24 ng/mL was found to be the optimal cutoff level for predicting positive and negative scans, while for patients previously treated with radiotherapy (RT) it was 5.75 ng/mL. In RP-patients with PSA value <1.24 ng/mL, 52% scans were positive, whereas patients with PSA ≥1.24 ng/mL had positive scan results in 87%. RT-patients with PSA <5.75 ng/mL had positive scans in 86% and and for those with PSA ≥5.75 ng/mL 94% had positive scans. This study identifies the PSA and PSA kinetics threshold levels for the presence of 68Ga-PSMA-11 PET/CT-detectable PC-lesions in BC patients.
Cancers. 2020 Feb 08*** epublish ***
Manuela Andrea Hoffmann, Hans-Georg Buchholz, Helmut J Wieler, Matthias Miederer, Florian Rosar, Nicolas Fischer, Jonas Müller-Hübenthal, Ludwin Trampert, Stefanie Pektor, Mathias Schreckenberger
Department of Occupational Health & Safety, Federal Ministry of Defense, 53123 Bonn, Germany., Clinic of Nuclear Medicine, Johannes Gutenberg-University, 55101 Mainz, Germany., Clinic of Nuclear Medicine, Bundeswehr Central Hospital, 56072 Koblenz, Germany., Department of Urology, Helios Kliniken Krefeld, 47805 Krefeld, Germany., Practice of Radiology and Nuclear Medicine, Praxis im KölnTriangle, 50679 Köln, Germany., Clinic of Nuclear Medicine, Klinikum Mutterhaus der Borromäerinnen, 54290 Trier, Germany.