Multi-Institutional Assessment of Performance Metrics for MRI-Targeted Transperineal Prostate Biopsy.

Abstract

Evidence supports obtaining MRI before prostate biopsy. Deliverables of MRI include improving prostate cancer detection through targeting of MRI lesions and reducing the total number of biopsies by eliminating the need for nontargeted biopsy. Actionable Intelligence Metric (AIM) and Reduction Metric (ReM) have been proposed to quantify these 2 deliverables; however, this work was performed in the transrectal biopsy setting. To assess generalizability, we examined AIM and ReM in a large, multi-institutional cohort of men undergoing transperineal biopsy. All patients undergoing concurrent MRI-targeted and systematic transperineal biopsy and maintained in prospective prostate cancer databases across 5 institutions were included. AIM is the percent of men in whom targeted biopsy detected a higher grade group compared with systematic biopsy alone. ReM is the proportion of men in whom systematic biopsy may be omitted. In addition to total cohort evaluations of AIM and ReM, subgroup analyses and multivariable logistic regression were performed. In total, 1,587 transperineal biopsies were analyzed; 797 (50%) had ≥ grade group 2 prostate cancer. AIM in the overall cohort was 27.4%, and ReM was 83.3%. When stratified by PIRADS score and prior biopsy status, AIM and ReM were > 25% and > 80%, respectively, across all subgroups. On multivariable logistic regression, PI-RADS 5 lesions and biopsies performed at institution D were predictive of higher rates of upgrading on systematic biopsy, while patients with a prior negative biopsies had a decreased likelihood of systematic upgrading. AIM and ReM can be applied in the transperineal setting to assess deliverables of MRI-targeted prostate biopsy. Targeted biopsies provided actionable information in 27% of men, while up to 17% of clinically significant cancer would be missed if systematic biopsy were omitted. Individualized assessment of patient risk tolerance is necessary if a targeted biopsy-alone approach is to be adopted.