Efficacy of MRI/US guided fusion biopsy with transperineal approach for histological verification of clinically significant prostate cancer localized in the anterior fibromuscular stroma of the prostate

Introduction: Prostate cancer necessitates precise diagnostic methods to ensure timely and appropriate treatment. The advancement of magnetic resonance imaging (MRI), combined in real-time with ultrasound (US) via fusion technology, has enabled enhanced targeted biopsy capabilities. Tumors located within the anterior fibromuscular stroma have traditionally posed significant challenges for histological verification due to limited accessibility by transrectal biopsy. The adoption of a transperineal approach significantly improves diagnostic efficacy in this anatomically challenging region. Objective: The present study aims to evaluate the diagnostic performance of MRI/US fusion biopsy via transperineal access in detecting clinically significant prostate cancer localized in the anterior zone. Materials and Methods: A retrospective analysis was performed on patient data collected from January 2023 to June 2025. All patients with elevated total prostate-specific antigen (tPSA) levels underwent MRI assessment with lesions scored according to PI-RADS criteria. Patients presenting with lesions localized to the anterior zone and rated PI-RADS 3 or higher underwent MRI/US fusion-guided transperineal biopsy. Histopathological outcomes were subsequently analyzed. Results: The cohort consisted of 508 patients, of whom 19.7% (100 patients) demonstrated MRI-detected lesions localized in the anterior zone. The mean age within this subgroup was 66.9 ± 9.2 years. Mean tPSA was 13.6 ± 9.1 ng/ml, with an average prostate volume of 46.2 ± 15.8 cc. Lesion distribution by PI-RADSscore was as follows: 35% PI-RADS 3, 50% PI-RADS 4, and 15% PI-RADS 5. Histopathological examination revealed benign prostatic hyperplasia in 27 % or 27 of cases, High Grade PIN in 6 patients; low-grade prostate cancer in 43% (43 patients), and high-grade prostate cancer in 24% (24 patients). Gleason scores were assigned to all positive biopsies, with 15.9% classified as Gleason 3+3=6, 43.4% as Gleason 7 (30.1% Gleason 3+4 and 13.3% Gleason 4+3), 6.2% as Gleason 8, and 4.4% as Gleason 9. Conclusion: MRI/US fusion biopsy performed via a transperineal approach represents an effective and reliable technique for diagnosing clinically significant prostate cancer located in the anterior zone of the prostate. This method enhances the accuracy of histological confirmation in lesions that are difficult to access through traditional transrectal biopsy and facilitates precise evaluation of tumor aggressiveness. Keywords: magnetic resonance imaging, ultrasound, fusion biopsy, clinically significant prostate cancer, anterior zone