This study explores a new treatment called proton radiation therapy for men with high-risk prostate cancer. Prostate cancer is a disease where cells in the prostate (a small gland in men) grow uncontrollably. Proton radiation therapy uses powerful beams of particles called protons to target cancer cells more precisely, which might mean fewer side effects like tummy issues (gastrointestinal) or trouble with peeing (genitourinary).

This study checks if proton radiation can safely treat the affected areas and looks at any side effects patients might feel. The treatment is given Monday through Friday, and some patients might get extra radiation called brachytherapy. After treatment, patients will be checked regularly for up to three years to see how they are doing.

• The study lasts up to 3 years with regular follow-ups.
• Participants receive proton therapy five days a week.
• Not suitable for those with prior prostate surgery or certain illnesses.