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.