A Phase II Prospective Blinded Trial of MRI and In-Bore Biopsy in Active Surveillance for Prostate Cancer

OBJECTIVE:To demonstrate the added benefit of multiparametric (mp)MRI risk stratification during active surveillance. METHODS:This prospective, single-arm, non-randomized study included 82 men with low-risk PCa. We compared two biopsy strategies in parallel. The first biopsy strategy was an in-bore and TRUS biopsy in men with suspicious mpMRI findings. The second was a TRUS biopsy in all 82 men, blinded to the results of the previously performed mpMRI. RESULTS:We identified 27/82 men with suspicious mpMRI. Of those 27 men, we detected 8/27 with csPCa on biopsy, and we identified two men with in-bore biopsy exclusively, three men with TRUS biopsy exclusively, and three men with both biopsy strategies. Of the 55/82 men with non-suspicious mpMRI (who only received TRUS biopsies), two men had csPCa. TRUS biopsy of the entire cohort of 82 men would have led to the correct diagnosis of 80% men with csPCa, requiring all 82 men to receive biopsies (csPCa in 10% of the 82 biopsies). Conducting in-bore biopsies plus TRUS biopsies in men with suspicious mpMRI would have also led to the detection of 80% of men with csPCa, requiring only 27 men to receive biopsies (csPCa in 30% of the 27 biopsies). CONCLUSIONS:The combination of TRUS and in-bore biopsies, limited to men with suspicious mpMRI, resulted in a similar detection rate of csPCa compared to TRUS biopsies of all men but required only one-third of men to undergo biopsy. Our results indicate that in-bore and TRUS biopsies continue to complement each other.