The Imperial Prostate 9 - Approaches To Long-term Active Surveillance: Regular MRI scans versus standard of care (IP9-ATLAS) randomised controlled trial

INTRODUCTION AND OBJECTIVES: Active surveillance is heterogenous using combinations of prostate specific antigen (PSA), digital rectal exam (DRE), magnetic resonance imaging (MRI) and biopsy. Using serial prostate MRI scans during active surveillance to inform when to conduct repeat biopsies might be effective to balance the burden of testing and detecting cancer progression early. IP9-ATLAS aims to determine whether regular MRI scans during active surveillance, compared to current standard of care (clinically-indicated MRI scans), will improve detection of cancer progression over 5 years. METHODS: IP9-ATLAS is a prospective, multi-centre RCT including patients with a histological diagnosis of Grade Group 1 or 2 disease on active surveillance. It compares UK NICE-defined standard of care (regular PSA and DRE when indicated with clinically-guided use of repeat MRI and biopsy), against the intervention arm (regular PSA and regular prostate MRI scans without intravenous contrast medium (i.e. biparametric), planned yearly for patients with an MRI-visible cancer lesion or Grade Group 2 cancer and every 2 years for all other patients). An internal pilot will determine the feasibility of the trial. 1263 patients will be recruited. Ethics committee approval has been granted by the Health Research Authority Research Ethics Committee Wales. RESULTS: The primary outcome is cancer progression rate, defined as higher risk cancer on biopsy (Grade Group ≥3) or a higher stage (≥T3 or ≥ N or ≥ M1) over 5 years. Secondary outcomes will include treatment rates without progression, adverse events, cost-effectiveness and functional outcomes. Recruitment started in May 2024 and is due to complete in June 2027, with follow-up until 2032. The trial is registered with the ISRCTN and Clinical Trials.gov (ISRCTN11447662 / NCT06280781). CONCLUSION: IP9-ATLAS aims to provide robust level 1 comparative data to improve active surveillance protocols and change practice.