Utility of multiple core biopsies during transperineal template-guided mapping biopsy for patients with large prostates and PI-RADS 1–2 on multiparametric magnetic resonance imaging

BACKGROUND: We investigated the necessity of multiple core biopsies when performing transperineal template-guided mapping biopsy (TTMB) for patients with large prostates and no suspicious lesions on multiparametric magnetic resonance imaging (mpMRI). MATERIALS AND METHODS: We retrospectively analyzed 304 patients on active surveillance (AS), 212 patients with previously negative transrectal ultrasound-guided biopsy (TRUS-Bx) and 67 biopsy naïve patients who underwent TTMB between May 2017 and December 2020. The number of core biopsies and acute urinary retention (AUR) rates were analyzed in relation to the prostate volume (PV). Cancer detection rate according to the prostate volume and Prostate Imaging-Reporting and Data System (PI-RADS) scores were compared using the Pearson Chi-square test. RESULTS: AUR occurred more frequently in patients with PV over 39 cc (5.5% vs. 24.4%, P < 0.001). In addition, incidence of AUR was more in patients with PV over 39 cc and PI-RADS score of 1–2 on mpMRI (3.7% vs. 22.2%, P < 0.001). There was no significant difference in the detection rates of any prostate cancer or clinically significant prostate cancer (csPCA) between the patients on AS with PV < 39 cc and PV ≥ 39 cc and PI-RADS score 1–2 (57.4% vs. 50%, P = 0.507; 17% vs. 8.8%, P = 0.412, respectively). Additionally, no significant difference was found in the detection rates of any prostate cancer or csPCA between the patients with PV < 39 cc and PV ≥ 39 cc and PI-RADS score 1–2 who either had a previously negative TRUS-Bx or were biopsy naïve (27.9% vs. 16.2%, P = 0.101, 8.2% vs. 4.1%, P = 0.31, respectively). CONCLUSION: Increasing the number of core biopsies of prostates measuring ≥39 cc with PI-RADS 1–2 on mpMRI does not significantly increase the detection rates of any prostate cancer or csPCA.