Combined Androgen Deprivation Therapy with Relugolix and Image-Guided Stereotactic Body Radiotherapy (SBRT)

The goal of this study is to evaluate the recovery of erectile function at six months after hormonal therapy cessation in male patients affected by advanced prostate cancer and undergoing radiotherapy. The main questions are: * How well and how quickly do patients recover their sexual function and overall quality of life after stopping hormone therapy and receiving radiotherapy? * How do the details of the radiation treatment (like the dose and how it's delivered) relate to treatment success, side effects, and long-term outcomes such as cancer control, survival, and financial impact? Participants will receive hormonal therapy (Relugolix) following by radiotherapy. They will complete questionnaires on sexual function, quality of life, and financial impact before, during and after treatment, and attend follow-up visits for health assessments. The study will measure how many patients recover erectile function within six months of stopping hormonal therapy, how long recovery takes, how treatment doses relate to outcomes, and assess cancer control, side effects, quality of life, and survival.