Tri-modal PSMA PET/CT-MRI-US fusion biopsy for clinically significant prostate cancer: a prospective paired diagnostic study.

Abstract

PurposeMultiparametric MRI (mpMRI)-ultrasound (US) fusion biopsy misses 8%-20% of clinically significant prostate cancer (csPCa), leaving a detection gap that prostate-specific membrane antigen (PSMA) PET/CT may help close. Whether incorporating PSMA into an MRI-US fusion platform improves csPCa detection has not been evaluated in a prospective paired design. We compared tri-modal PSMA PET/CT-MRI-US fusion biopsy with MRI-US fusion biopsy and systematic biopsy.MethodsIn this prospective, single-center, and paired diagnostic accuracy study (STARD 2015; ChiCTR2400089436), 308 biopsy-naive men underwent tri-modal fusion biopsy, MRI-US fusion biopsy, and systematic biopsy in a single session. The primary endpoint was the absolute difference in patient-level csPCa detection (International Society of Urological Pathology grade group ≥ 2) between tri-modal and MRI-US fusion biopsies.ResultsTri-modal fusion detected 4.9% more csPCa than MRI-US fusion biopsy (95% confidence interval 2.4%-7.3%; P ConclusionTri-modal fusion was superior to MRI-US fusion biopsy in detecting csPCa, particularly in small PSMA-positive and PI-RADS 4 lesions. A PSMA-derived risk score enabled effective stratification, and in the test set, a simulated risk-guided approach showed potential for biopsy reduction. These findings require multicenter validation before clinical adoption.Trial registrationChiCTR2400089436 (Chinese Clinical Trial Registry, http://www.chictr.org.cn/ , registered 2024-09-09).