Accurate risk assessment is essential for men on active surveillance (AS) of prostate cancer (PCa). Multiparametric MRI improves detection of clinically significant PCa (csPCa; Grade Group ≥2) but is limited by registration error, contraindications and long wait times. Micro-ultrasound (microUS) is a high-resolution, real-time imaging modality that has been shown to be non-inferior to MRI for the detection of csPCa in biopsy-naïve men. However, trials comparing microUS against MRI in men managed by AS remain limited.
MUSIC-AS is a paired, within-subject, prospective non-inferiority diagnostic trial comparing microUS and MRI for the detection of csPCa in men undergoing confirmatory biopsy during AS. Eligible participants include men with previously diagnosed Grade Group 1 PCa requiring confirmatory biopsy. Each participant will undergo pre-biopsy MRI followed by a microUS/MRI-guided biopsy (in which the operator is initially blinded to the MRI during acquisition of microUS targeted cores) followed by MRI targeted cores and systematic sampling. The primary endpoint is the detection of csPCa by combined targeted plus systematic biopsies. The planned sample size is 210 participants.
The primary hypothesis is non-inferiority of the csPCa detection rate between microUS-targeted plus systematic biopsies and MRI-targeted plus systematic biopsies. Secondary analyses will evaluate upgrade-free probabilities at 2, 5, and 10 years after confirmatory biopsy. An exploratory analysis using germline sequencing will be performed.
MUSIC-AS will determine whether micro-ultrasound is non-inferior to MRI for detecting csPCa in men on active surveillance. Confirmation of non-inferiority may support microUS as a cost-effective, time-efficient, and widely accessible imaging alternative in this population.
Contemporary clinical trials communications. 2026 Apr 17*** epublish ***
Oliver Little, Pat Albers, Tarek A Bismar, Wayne Brisbane, Stacey Broomfield, Silvia Chang, Christopher Fung, Sunita Ghosh, Tomislav Kuliš, Hugo Lavigueur-Blouin, Giovanni Lughezzani, Miles Mannas, Peter Metcalfe, Luka Penezić, Wendy Tu, Toni Zekulić, Adam Kinnaird
Undergraduate Medical Education, Cumming School of Medicine, University of Calgary, Calgary, Canada., Division of Urology, Department of Surgery, University of Alberta, Edmonton, Canada., Department of Pathology & Laboratory Medicine, Oncology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada., Institute of Urologic Oncology, Department of Urology, UCLA Medical Center, University of California Los Angeles, USA., Department of Radiology, University of British Columbia, Vancouver, Canada., Department of Radiology & Diagnostic Imaging, University of Alberta, Edmonton, Canada., Department of Oncology, University of Alberta, Edmonton, Canada., Department of Urology, University Hospital Center Zagreb, Zagreb, Croatia., Division of Urology, Department of Surgery, Université de Montréal, Quebec, Canada., Departments of Urology and Biomedical Sciences, Humanitas Clinical and Research Center, Rozzano, Italy., Vancouver Prostate Centre, Mohseni Institute of Urologic Sciences, Vancouver, British Columbia, Canada.