Patterns of use of chemotherapy with radiotherapy in the treatment of muscle-invasive bladder cancer: Data from the RAIDER randomized trial of adaptive radiotherapy.

503 Background: Level 1 evidence exists for the use of both neoadjuvant chemotherapy (NAC) and concomitant radiosensitization (CRS) to improve outcomes in patients receiving radical radiotherapy (RT) for muscle invasive bladder cancer, but uptake has been patchy. We report here the current patterns of usage in an ongoing trial of adaptive radiotherapy. Methods: RAIDER is an international randomized phase II trial recruiting patients with...