Surgery With or Without Postoperative Intensity Modulated Radiation Therapy in Treating Patients With Urothelial Bladder Cancer

PRIMARY OBJECTIVE: I. To evaluate the ability of postcystectomy adjuvant radiotherapy to safely reduce pelvic tumor recurrence, defined as pelvic recurrence-free survival. SECONDARY OBJECTIVES: I. Evaluate increase in disease-free survival. II. Evaluate toxicity of adjuvant pelvic radiotherapy. OUTLINE: Patients are randomized to 1 of 2 treatment arms. Patients are stratified by neoadjuvant preoperative or postoperative adjuvant chemotherapy. After completion of study treatment, patients are followed up at 6 weeks, every 3 months for 1 year, every 4 months for 1 year, every 6 months for 3 years, and then annually for 5 years.