OBJECTIVES: To examine the role of multiparametric magnetic resonance imaging (mpMRI) in enhancing prostate cancer (PCa) detection and selecting candidates for active surveillance (AS), given that its utility in monitoring disease progression remains unclear. PATIENTS AND METHODS: The Miami Active Surveillance Trial (MAST) is a prospective trial of men undergoing serial mpMRI and biopsies on AS for PCa. Participants had annual mpMRI with MRI-targeted and systematic biopsies at confirmatory (12-18 months) and subsequent intervals (12, 24, and 36 months). Grade progression was defined as an upgrade from Grade Group (GG) 1 to GG ≥2 or GG 2 to GG ≥3. The performance of MRI was evaluated at baseline (prior to confirmatory biopsy) and on subsequent biopsies for association with grade progression. Fine and Gray competing-risk models evaluated MRI for predicting grade progression after controlling for risk factors. RESULTS: Among 205 men, 79 (38.5%) had grade progression at the conclusion of the trial (36 months), with 40 (19.5%) men having grade progression at confirmatory biopsy, and the remaining 39 (2.0-9.8%/year) progressing on subsequent biopsies. A Prostate Imaging-Reporting And Data System (PI-RADS) score of 4 or 5 (vs no suspicious lesions or PI-RADS 1 and 2) on baseline MRI (prior to confirmatory biopsy) was an independent predictor of grade progression on confirmatory biopsy (Gray's test P < 0.001), with volume progression treated as a competing risk. At 36 months, MRI-only surveillance would have avoided 45% of biopsies but missed 32% of progression events. CONCLUSION: Pre-confirmatory biopsy MRI independently predicted grade progression on confirmatory and subsequent biopsies during AS; however, false positives and negatives still occur highlighting the need for periodic biopsy of the prostate.
Sharifi et al. (Wed,) studied this question.