Evaluating the diagnostic accuracy of transperineal prostate biopsy in unilateral MRI-target lesions

Background To evaluate the diagnostic value of target biopsies (TargB), TargB with ipsilateral systematic (TargB+IS), and TargB with contralateral systematic biopsies (TargB+CS) for the detection of clinically significant prostate cancer (csPCa).Methods A prospective evaluation of patients undergoing MRI-Ultrasound fusion transperineal biopsy was performed between January 2023 and February 2025. Patients with unilateral MRI-visible lesions (PIRADS grade 3–5) and PSA between 4 and 20 ng/mL were enrolled. The diagnostic accuracy of TargB (group 1), TargB+IS (group 2), and TargB+CS (group 3) was evaluated versus the presence of csPCa in any systematic or target biopsy (reference standard).Results 384 patients were included (PIRADS III in 180 (46.9%), IV in 152 (39.6%), and V in 52 (13.5%) patients). The sensitivity and NPV of TargB was 87.5%, and 93%, TargB+CS were 91.7% and 95.2%, and TargB+IS were 97.2% and 98.4%, respectively. TargB+IS achieved the highest negative predictive value (98.4%) across all PIRADS groups and when stratified according to the PIRADS score. The agreement between TargB+IS and csPCa was almost perfect (Kappa: 0.98, p < 0.001), with non-significant discordance (McNemar p = 0.1).Conclusions TargB+IS provides the lowest false-negative rate for csPCa detection compared to TargB alone or TargB+CS. Contralateral systematic biopsies may be omitted in selected patients, but ipsilateral systematic sampling remains essential to minimize missed diagnoses.