Imperial Prostate 9 - ATLAS (Approaches To Long-Term Active Surveillance)

The goal of this intervention study is for patients on active surveillance for prostate cancer, to demonstrate that use of regular MRI scans is better able to detect cancer progression over 5 years compared to the current NICE defined strategy. Research Question P - In patients who are on active surveillance for low to medium risk prostate cancer, I - is the use of regular MRI scans C - compared to current NICE defined standard of care, O - better at detecting cancer progression with less cost to the NHS (fewer PSA tests, biopsies and clinic visits)? Patients will be allocated in a 1.1 ratio to either MRI scans or the current NICE defined standard. Randomisation will be blocked (random block size) and stratified by MRI visibility of lesions (3 categories \[ no visible lesion, diffuse changes, discrete visible lesion\]), cancer Grade Group (GG1, GG2) and time since diagnosis. This study will not be blinded to patients or physicians.