Using MRI to Identify Areas to Receive Lower Doses of Radiation Treatment in Men With Prostate Cancerdose Mapping to Preserve Quality of Life

This study is using specialized MRI scans to map where prostate cancer is most concentrated, so doctors can deliver higher radiation doses to those areas while reducing radiation to healthy tissue — with the goal of improving cancer control while preserving sexual and urinary function. **You may be eligible if...** - You are an adult male (18 or older) - You have been diagnosed with intermediate or high-risk prostate cancer (confined to the pelvis) confirmed by biopsy, and the tumor is visible on MRI - You have not had any prior treatment for prostate cancer (though being on active surveillance without treatment is acceptable) - You are generally in good health for radiation treatment **You may NOT be eligible if...** - Your cancer has spread beyond the pelvis (distant metastases) - You have had prior pelvic radiation or brachytherapy - You have another active cancer (except localized skin cancers) - You cannot have an MRI (e.g., due to metallic implants, severe claustrophobia, or poor kidney function that prevents contrast use) - You are having a spacer (hydrogel or hyaluronic acid) placed between the prostate and rectum Talk to your doctor to see if this trial is right for you.