Adjuvant Radiation for High Risk Bladder Cancer

Inclusion Criteria: * Pathologic diagnosis of urothelial or squamous cell carcinoma of the bladder * Patients must have undergone cystectomy (total cystectomy, radical cystectomy +/- pelvic lymph node dissection) with no evidence of macroscopic residual disease * Eastern Cooperative Oncology Group (ECOG)/Zubrod performance status of 0-2 * Patients treated with simple cystectomy with macroscopically negative margins are eligible for this study * Clinical T-stage (prior to systemic therapy, if applicable) ≥ T3a and/or positive lymph nodes by transurethral resection of bladder tumor (TURBT)/magnetic resonance imaging (MRI)/computed tomography (CT)/positron emission tomography (PET)-CT or pathologic T-stage ≥ T3a and/or positive lymph nodes Exclusion Criteria: * Patients with metastatic disease outside of the pelvis * Prior invasive malignancy (except non-melanomatous skin cancer) unless disease free for a minimum of 3 years * Prior radiation therapy to the pelvis * Patients with active inflammatory bowel disease * Severe acute co-morbidity, defined as follows: * Unstable angina and/or congestive heart failure requiring hospitalization in the last 3 months * Transmural myocardial infarction within the last 6 months * Acute bacterial or fungal infection requiring intravenous antibiotics at the time of registration * Chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy at the time of registration * Acquired immune deficiency syndrome (AIDS) based upon current Centers for Disease Control and Prevention (CDC) definition; note, however, that human immunodeficiency virus (HIV) testing is not required for entry into this protocol; the need to exclude patients with AIDS from this protocol is necessary because the treatment involved in this protocol may be significantly immunosuppressive; protocol-specific requirements may also exclude immunocompromised patients