Optimal sampling scheme in men with abnormal multiparametric MRI undergoing MRI-TRUS fusion prostate biopsy.

OBJECTIVES: To determine the implications of different prostate sampling schemes on the diagnosis of clinically significant prostate cancer (csPCA, ISUP group 2-5) and clinically insignificant prostate cancer (ciPCA, ISUP group 1) in men with abnormal multiparametric magnetic resonance imaging (mpMRI) undergoing MRI-transrectal ulrasound fusion targeted biopsies. MATERIALS AND METHODS: This is a retrospective analysis of a cohort including all men who had a single lesion on mpMRI of the prostate performed between January 2016 and June 2017. All men underwent an MRI-transrectal ulrasound fusion biopsy and systematic (SBx) sampling of the prostate, which combined and were considered the standard of reference. The hypothetical 3 biopsy sampling schemes were defined as follows: Targeted biopsy only (TBx), TBx + ipsilateral SBx (ipsi-SBx) and TBx + contralateral SBx (contra-SBx) and were evaluated for the detection of csPCA and ciPCA. Sensitivity and 95% intervals were calculated, McNemar test was used to compare sensitivities between the various sampling schemes. RESULTS: TBx + SBx detected csPCa in 47% (55 of 116) of the 116 men who met eligibility criteria. Sensitivity and 95% confidence intervals for csPCa detection was 85.5% (73.3%-93.5%), 96.4% (87.5%-99.6%), and 92.7 (82.4%-98%) for TBx alone, TBx + ipsi-SBx and TBx + contra-SBx, respectively. csPCa detection rates were higher for both TBx + ipsi-SBx and TBx + contra-SBx compared to TBx alone. Clinically insignificant cancers alone were detected in 7.7% (9 of 116), 10.3% (12 of 116), and 14.6% (17 of 116) of the cohort by TBx only and TBx + ipsi-SBx, and TBx + contra-SBx, respectively. CONCLUSIONS: TBx + ipsi-SBx may increase the detection of csPCa while limiting overdiagnosis of indolent cancers.