Meeting Cancer Detection Benchmarks in MRI/Ultrasound Fusion Biopsy for Prostate Cancer: Insights from a Retrospective Analysis of Experienced Urologists.

Abstract

Background: The relationship between case volume and clinical outcomes is well established for most urological procedures but remains underexplored in prostate ultrasound/MRI fusion biopsy (UMFB). UMFB aims to detect clinically significant prostate cancer (csPCa) by adhering to cancer detection benchmarks for PI-RADS lesions identified via multiparametric MRI (mpMRI). These benchmarks, defined by Ahmed et al., include cumulative cancer detection rate (C-CDR) targets of >80% for PI-RADS 5, >50% for PI-RADS 4, and <20% for PI-RADS 1-3.

Methods: This retrospective, single-center study analyzed the case volumes required for two experienced urologists (U1 and U2, each with >15 years of practice) to consistently achieve the Ahmed-defined C-CDR benchmarks for csPCa (ISUP grade ≥ 2) using UMFB. Both transrectal and transperineal approaches were included to enable comprehensive learning curve analysis. Data from 2017 to 2023 were reviewed, encompassing 157 UMFBs performed by U1 and 242 by U2, with a transrectal-to-perineal ratio of 7:3.

Results: Both urologists achieved Ahmed-defined C-CDR targets from the outset. Over a median follow-up of 30 months, patients with initial PI-RADS 4 or 5 ratings and negative primary biopsies remained prostate cancer-free in 77% of cases for U1 and 91.2% for U2 (p = 0.152).

Conclusions: This study demonstrates that experienced urologists can achieve high diagnostic accuracy and maintain patient safety immediately upon implementing UMFB, meeting established benchmarks without requiring additional procedural learning.