The Added Value of Systematic Biopsy in Biopsy-Naïve Patients Undergoing Magnetic Resonance Imaging–Transrectal Ultrasound Fusion Prostate Biopsy

Purpose: The added value of systematic biopsy (SBx) for detection of clinically significant prostate cancer (csPCa) in biopsy-naïve patients undergoing MRI-targeted biopsy (TBx) has been reported. However, the added value of SBx for ISUP upgrading and csPCa localization has not been fully investigated. In this study, we evaluated the added value of SBx in biopsy-naïve patients undergoing MRI-transrectal ultrasound fusion biopsy. Patients and Methods: We retrospectively evaluated 220 consecutive biopsy-naïve men with a prebiopsy positive MRI (PIRADS ≥ 3) and prostate-specific antigen ≤ 20 ng/mL who underwent MRI–transrectal ultrasound fusion biopsy and systematic 16-core biopsy. Only TBx data for the index lesion (IL) were used when multiple lesions were present on prebiopsy MRI. The csPCa detection rate (International Society of Urological Pathology grade group [ISUP GG] ≥ 2) was compared between TBx, SBx, and TBx + SBx. The frequency of potentially missed csPCa by TBx alone was determined. GG discrepancies and csPCa localization were compared between TBx and SBx. Results: The overall csPCa detection rate (TBx + SBx) was 54.5% (120/220). The csPCa detection rate was higher for TBx (50.9%, 112/220) than for SBx (45%, 99/220). TBx alone missed csPCa in 8 patients (6.6%, 8/120). SBx led to GG upgrading in 25 (23.5%) of 106 patients who were positive on both TBx and SBx. Of 110 patients with the IL in the peripheral zone (PZ), 76 (69.0%) were diagnosed with csPCa on TBx and 51 (46.3%) had concomitant csPCa in the transition zone (TZ) on SBx. Of 110 patients with the IL in TZ, 36 (32.7%) were diagnosed with csPCa on TBx and 16 (14.5%) had concomitant csPCa in PZ on SBx. Conclusion: SBx had the added value for the detection of csPCa, GG upgrading, and csPCa localization in biopsy-naïve patients undergoing MRI–transrectal ultrasound fusion biopsy.