The goal of this clinical trial is to learn if adaptive radiation boost works to treat genitourinary cancers, esp. in the context of prostate cancer patients with post-prostatectomy local relapse and bladder cancer patients with bladder-conserving treatment. It will also learn about the safety and efficacy of adaptive boost. The main questions it aims to answer are: Does adaptive boost lower the toxicities? Does adaptive boost maintain or improve the clinical efficacy? Participants will: Undergo adaptive boost on 1.5-Tesla MR-Linac Visit the clinic once every 2 weeks during RT, and every 3 months post-ART Keep a regular QOL questinnaire completion