Confirmatory biopsy of men under active surveillance: extended versus saturation versus multiparametric magnetic resonance imaging/transrectal ultrasound fusion prostate biopsy.

Objective: The aim of this study was to evaluate the detection rate for clinically significant prostate cancer (PCa) after multiparametric magnetic resonance imaging (mpMRI)/transrectal ultrasound (TRUS) fusion biopsy versus extended biopsy or saturation prostate biopsy (SPBx) in men enrolled on active surveillance (AS).

Materials And Methods: From May 2013 to January 2016, 100 men with very low-risk PCa were enrolled on AS. Eligible criteria were: life expectancy greater than 10 years, cT1c, prostate-specific antigen (PSA) below 10 ng/ml, PSA density less than 0.20 ng/ml², three or fewer unilateral positive biopsy cores, Gleason score (GS) equal to 6 and greatest percentage of cancer in a core 50% or lower. All patients underwent 3.0 T pelvic mpMRI before confirmatory transperineal extended biopsy (20 cores) and SPBx (median 30 cores) combined with mpMRI/TRUS fusion targeted biopsy (median four cores) of suspicious lesions [Prostate Imaging Reporting and Data System (PI-RADS) 3-5]. Clinically significant PCa was defined as the presence of at least one core with a GS of 4 or higher.

Results: After confirmatory biopsy, 16 out of 60 (26.6%) patients showed significant PCa. Targeted biopsy of PI-RADS 4-5 versus PI-RADS 3-5 lesions diagnosed six out of 16 (37.5%) and 12 out of 16 (87.5%) significant PCa, respectively, with two false positives (5%). The detection rate for significant PCa was equal to 68.8% on mpMRI/TRUS fusion biopsy, 75% on extended biopsy and 100% on SPBx. mpMRI/TRUS targeted biopsy and extended biopsy missed five out of 16 (31.2%) and four out of 16 (25%) PCa, respectively.

Conclusions: Although mpMRI may improve the diagnosis of significant PCa in men under AS, SPBx had a higher detection rate for clinically significant PCa.