Differential detection rates of clinically significant prostate cancer in transition zone versus peripheral zone lesions: Implications for transperineal magnetic resonance imaging-targeted biopsy strategy

The optimal approach for targeting lesions in the transition zone (TZ) versus the peripheral zone (PZ) during magnetic resonance imaging (MRI)-guided prostate biopsy remains unclear. This study investigated whether lesion location could predict the detection of clinically significant prostate cancer (csPCa) in MRI-targeted biopsies. We conducted a retrospective analysis of 338 consecutive patients who underwent MRI/ultrasound fusion-guided targeted biopsy from April 2023 to October 2024. All participants presented with PI-RADS 3–5 lesions and received both targeted and systematic transperineal biopsies. Lesions were categorized as “TZ-only” (restricted to the TZ) or “PZ-included” (involving the PZ). The primary endpoint was the identification of csPCa (Gleason score ≥ 3 + 4) in targeted biopsy samples. Multivariable logistic regression was used to assess independent predictors. Of the 338 patients, 173 (51.2%) had TZ-only lesions, while 165 (48.8%) had PZ-included lesions. The overall csPCa detection rate (positive findings in either targeted or systematic biopsy) was 52.4%, with targeted biopsy detecting csPCa in 40.8% of cases. Targeted biopsy positivity was significantly lower for TZ-only lesions compared to PZ-included lesions (27.2% vs. 55.2%, P < 0.001), with the greatest disparity seen in PI-RADS 4 lesions (24.8% vs. 53.8%). TZ-only location was found to be an independent negative predictor in multivariable analysis (OR = 0.367; 95% CI, 0.207–0.650; P < 0.001). PSA density (OR = 35.2, P = 0.002) and PI-RADS score (PI-RADS 4, OR = 5.49; PI-RADS 5, OR = 6.80, both P = 0.013) emerged as strong positive predictors. MRI-targeted biopsy yielded significantly lower csPCa detection rates in TZ-only lesions compared to those involving the PZ, especially for PI-RADS 4 lesions. These results underscore the importance of individualized biopsy strategies that place greater emphasis on systematic sampling and clinical indicators for TZ lesions.