This is a multicenter, randomized, open-label phase 2 study for men with metastatic hormone-sensitive prostate cancer. About 254 participants will first receive 6 months of darolutamide plus androgen deprivation therapy. Participants whose cancer has not progressed and who still have active tumor lesions on prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) will then be randomly assigned to one of two groups. One group will continue darolutamide plus androgen deprivation therapy. The other group will receive stereotactic body radiotherapy (SBRT) to all active tumor lesions identified by PSMA PET/CT, while continuing darolutamide plus androgen deprivation therapy. The main purpose of this study is to find out whether adding PSMA PET/CT-guided SBRT can help participants live longer without tumor growth seen on scans or death. The study will also evaluate prostate-specific antigen (PSA) changes, time to castration-resistant prostate cancer, overall survival, side effects, and quality of life.