External Validation of the PROMOD Strategy, Combining PI-RADS Score and PSA Density, to Select Patients for Prostatic Biopsies.

PURPOSE: Combining MRI PI-RADS score (Prostate Imaging Reporting and Data System) with prostate-specific antigen density (PSAd) may optimize prostate biopsy (PBx) decisions. We aimed to externally validate the PROMOD strategy, combining PI-RADS with PSAd. PATIENTS AND METHODS: We retrospectively included 972 men who underwent PBx, i.e. 12-core systematic, 2-4 targeted (MRI-FUSION) between 2013 and 2022, recorded in a prospectively maintained database. Patients with PSA > 20 ng/mL or prior prostate cancer (PCa) were excluded. We evaluated rates of avoided PBx, missed low-grade cancers, and csPCa (ISUP grade ≥2) according to 10 strategies. Decision curve analysis (DCA) assessed net benefit. RESULTS: According to DCA, the highest net benefit in biopsy-naïve men was obtained by Strategies 8 (PI-RADS 4-5 or PI-RADS 3 with PSAd >0.15 ng/mL2) and 7 (PI-RADS 4-5 or PI-RADS 3 with PSAd >0.20 ng/mL2) reducing biopsies by 18-20% (95% CIs 15.5-21.2 and 16.9-22.7), missing 5-8% csPCa (95% CIs 3.8-8.4 and 4.9-10.0). Strategy 10 (PI-RADS 4-5 or PI-RADS 3 with PSAd >0.10 ng/mL2 or PSAd >0.20 ng/mL2) was more conservative, avoiding 12% PBx (95% CI 9.7-14.5) and 2% missed csPCa (95% CI 0.9-3.8). Similar patterns were observed in the previous negative biopsy group. CONCLUSION: The PROMOD Strategy is an effective tool allowing a tailored decision to perform PBx based on degrees of risk that both patients and clinicians are willing to accept, in the context of shared decision-making.