RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. Specialized radiation therapy that delivers a high dose of radiation directly to the tumor may kill more tumor cells and cause less damage to normal tissue.

PURPOSE: This phase I trial is studying the side effects and best dose of 3-dimensional conformal radiation therapy in treating patients with bladder cancer who have undergone transurethral resection of the bladder.

OBJECTIVES:

Primary

• To determine the maximum-tolerated dose of external-beam radiotherapy delivered as a tumor boost in patients who have undergone prior transurethral bladder resection for muscle-invasive carcinoma of the bladder.

Secondary

• To document progression-free survival and overall survival of these patients.
• To evaluate patterns of recurrence and bladder preservation rates following dose-escalated radiotherapy in these patients.
• To determine the impact of acute and late toxicity on quality of life in these patients.
• To assess the use of gold seeds for tumor boost delineation in these patients.
• To evaluate the use of virtual cystoscopy tumor localization in these patients.
• To assess coverage of the phase II radiotherapy boost volume on the daily cone-beam images.
• To assess coverage of the phase III radiotherapy volume on cone-beam images with selected adaptive strategy.
• To evaluate the use of diffusion-weighted MRI (dwMRI) scans in assessing response to radiotherapy.

OUTLINE: This is a dose-escalation study.

Patients undergo a rigid cystoscopy and gold-seed insertion, if clinically appropriate. Approximately 3-5 seeds are inserted into the bladder wall to demarcate the maximum extent of visible tumor or tumor bed via a customized introducer. All patients undergo 3-dimensional conformal radiotherapy once daily, 5 days per week during weeks 1 and 4-7 and once daily, 4-6 days per week during weeks 2 and 3, using a combination of image-guided radiotherapy techniques and a partial bladder radiotherapy boost.

Patients complete quality-of-life questionnaire QOL-30 at baseline, 1 and 3 months, and then annually after completion of study treatment.

After completion of study treatment, patients are followed up at 4, 8, and 12 weeks, every 6 months for 3 years, and then annually for 2 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed invasive bladder carcinoma, including the following cellular types:

  • Adenocarcinoma
  • Transitional cell carcinoma
  • Squamous cell carcinoma

• Clinical stage G1-3, pT2a-4 disease

  • Localized disease
  • No bone or visceral metastases
  • No lymph node metastases

• Has undergone maximal transurethral resection of the bladder tumor and planning to receive radical radiotherapy

PATIENT CHARACTERISTICS:

• WHO performance status 0-1

• Hemoglobin > 10 g/dL

• WBC > 3,000/mm^3

• Platelet count > 150,000/mm^3

• Creatinine < 120 μmol/L

• Bilirubin < 1.5 times upper limit normal (ULN)

• AST < 1.5 times ULN

• Alkaline phosphatase < 1.5 times ULN

• Not pregnant

• No inflammatory bowel disease or other significant small bowel disease

• Physically fit for radical radiotherapy

• No psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule

• No other malignancy within the past 2 years except adequately treated basal cell carcinoma of the skin or adequately treated carcinoma in situ of the cervix uteri

  • Prior superficial transitional cell carcinoma of the bladder allowed

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior pelvic surgery
• No bilateral hip replacements compromising accurate radiotherapy planning
• No prior radiotherapy to the pelvis