Ultra Hypofractionnated Radiotherapy With HDR Brachytherapy Boost.

This study is evaluating a radiation treatment approach for localized prostate cancer that combines a short course of external beam radiation (ultra-hypofractionation) with a high-dose internal radiation boost (HDR brachytherapy). Researchers want to see if this combination is effective and manageable for patients. **You may be eligible if...** - You are 18 or older with biopsy-confirmed prostate cancer (adenocarcinoma) - Your cancer is stage T1c or T2 (localized, not spread beyond the prostate) - Your PSA level is below 20 ng/mL - Your Gleason score is 6 or 7 (low to intermediate risk) - Your cancer has not spread to lymph nodes or distant organs **You may NOT be eligible if...** - Your cancer is stage T3 or T4 (has spread outside the prostate) - Your PSA is above 20 ng/mL - Your Gleason score is 8 to 10 (high-risk) - You have severe urinary symptoms (IPSS score > 20) - You have had prior pelvic radiation - You have inflammatory bowel disease or certain autoimmune conditions (lupus, scleroderma) - You have bilateral hip implants Talk to your doctor to see if this trial is right for you.