Value of Incremental Biopsy Cores for Microultrasound Targeted Prostate Biopsies

Abstract

ObjectivesTo determine the optimal number of cores needed during Micro-ultrasound informed prostate biopsy for the detection of clinically significant prostate cancer (csPCa, defined as Gleason Grade Group ≥2). MethodsA retrospective review of 1011 consecutive patients between Sep 2021 and July 2023 at our institution were identified; 536 underwent Micro-ultrasound biopsy and 475 underwent MRI/US targeted biopsy. Lesions were given a Prostate Risk Identification using Micro-ultrasound (PRI-MUS) score, with lesions PRI-MUS ≥3 targeted. MRI lesions were scored with Prostate Imaging-Reporting and Data System (PI-RADS) and lesions PI-RADS ≥3 were targeted. The primary outcome is the detection of csPCa stratified by number of cores. Results138 patients underwent targeted biopsies for Micro-ultrasound only lesions, 182 for Micro-ultrasound and MRI lesions and 426 underwent MRI/US for MRI lesions. The first targeted core detected 78.0% (46/59), 77.8% (63/81) and 78.8% (216/274) of csPCa for Micro-ultrasound, Micro-ultrasound+MRI and MRI/US respectively. Comparing first to third core, there was not a significant difference in overall detection of csPCa by Micro-ultrasound, though MRI/US was significantly different (28.4% vs 36.4% p=0.12, 32.5% vs 41.8% p=0.06, 42.5% vs 53.9% p<0.001 for Micro-ultrasound, Micro-ultrasound+MRI and MRI/US respectively). PI-RADS 3 and PRI-MUS 3 lesions had lower first core detection rates compared to PI-RADS 5 and PRI-MUS 5 lesions (44.4% vs 85.4% p=0.01, 65.2% vs 81.4% p=0.14, 60% vs 83.1% p=0.07 for Micro-ultrasound, Micro-ultrasound+MRI and MRI/US respectively). ConclusionsA three-core targeted biopsy per Micro-ultrasound lesion improves detection rate of clinically significant prostate cancer and should be considered to improve diagnostic accuracy.