Higher Preoperative Maximum Standardised Uptake Values (SUVmax) Are Associated with Higher Biochemical Recurrence Rates after Robot-Assisted Radical Prostatectomy for [68Ga]Ga-PSMA-11 and [18F]DCFPyL Positron Emission Tomography/Computed Tomography

This study aimed to investigate the association between the Ga-68- or F-18-radiolabeled prostate-specific membrane antigen (PSMA) tracer expression, represented by the maximum standardised uptake value (SUVmax) of the dominant intraprostatic lesion, and biochemical recurrence (BCR) in primary prostate cancer (PCa) patients prior to robot-assisted radical prostatectomy (RARP). This was a retrospective, multi-centre cohort study of 446 patients who underwent [Ga-68]Ga-PSMA-11 (n = 238) or [F-18]DCFPyL (n = 206) Positron Emission Tomography/Computed Tomography (PET/CT) imaging prior to RARP. SUVmax was measured in the dominant intraprostatic PCa lesions. [F-18]DCFPyL patients were scanned 60 ([F-18]DCFPyL-60; n = 106) or 120 ([F-18]DCFPyL-120; n = 120) minutes post-injection of a radiotracer and were analysed separately. To normalise the data, SUVmax was log transformed for further analyses. During a median follow-up of 24 months, 141 (30.4%) patients experienced BCR. Log(2)SUV(max) was a significant predictor for BCR (p < 0.001). In the multivariable analysis accounting for these preoperative variables: initial prostate-specific antigen (PSA), radiologic tumour stage (mT), the biopsy International Society of Urological Pathology grade group (bISUP) and the prostate imaging and reporting data system (PI-RADS), Log(2)SUV(max) was found to be an independent predictor for BCR in [Ga-68]Ga-PSMA-11 (HR 1.32, p = 0.04) and [F-18]DCFPyL-120 PET/CT scans (HR 1.55, p = 0.04), but not in [F-18]DCFPyL-60 ones (HR 0.92, p = 0.72). The PSMA expression of the dominant intraprostatic lesion proved to be an independent predictor for BCR in patients with primary PCa who underwent [Ga-68]Ga-PSMA-11 or [F-18]DCFPyL-120 PET/CT scans, but not in those who underwent [F-18]DCFPyL-60 PET/CT scans.