Can the Gleason score be predicted in patients with prostate cancer? A dynamic contrast-enhanced MRI, ((68))Ga-PSMA PET/CT, PSA, and PSA-density comparison study

PURPOSE: The present study aims to evaluate whether perfusion parameters in prostate magnetic resonance imaging (MRI), ((68))Ga-prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT), prostate-specific antigen (PSA), and PSA density can be used to predict the lesion grade in patients with prostate cancer (PCa). METHODS: The study included a total of 137 PCa cases in which 12-quadrant transrectal ultrasound-guided prostate biopsy (TRUSBx) was performed, the Gleason score (GS) was determined, and pre-biopsy multiparametric prostate MRI and ((68))Ga-PSMA PET/CT examinations were undertaken. The patient population was evaluated in three groups according to the GS: (1) low risk; (2) intermediate risk; (3) high risk. The PSA, PSA density, pre-TRUSBx ((68))Ga-PSMA PET/CT maximum standardized uptake value (SUV(max)), perfusion MRI parameters [maximum enhancement, maximum relative enhancement, T0 (s), time to peak (s), wash-in rate (s(-1)), and wash-out rate (s(-1))] were retrospectively evaluated. RESULTS: There was no significant difference between the three groups in relation to the PSA, PSA density, and ((68))Ga-PSMA PET/CT SUV(max) (P > 0.05). However, the values of maximum enhancement, maximum relative enhancement (%), T0 (s), time to peak (s), wash-in rate (s(-1)), and wash-out rate (s(-1)) significantly differed among the groups. A moderate positive correlation was found among the prostate volume, PSA (r = 0.490), and ((68))Ga-PSMA SUV(max) (r = 0.322) in the patients. The wash-out rate (s(-1)) and wash-in rate (s(-1)) had the best diagnostic test performance (area under the curve: 89.1% and 78.4%, respectively). CONCLUSION: No significant correlation was found between the ((68))Ga-PSMA PET/CT SUV(max) and the GS. The wash-out rate was more successful in estimating the pretreatment GS than the ((68))Ga-PSMA PET/CT SUV(max).