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.