Dose Escalation Trial of Endoluminal High-Dose-Rate Brachytherapy With Concurrent Chemotherapy for Rectal or Anal Cancer in Patients With Recurrent Disease or Undergoing Non-Operative Management

Patients will receive 3 fractions of endorectal brachytherapy, each spaced apart by 7 days (+/- 1 day). The three dose tiers will be 1500cGy (500cGy per fraction), 1800cGy (600cGy per fraction), and 2100cGy (700cGy per fraction).

"Patients will receive 500 mg and 150 mg oral tablets of capecitabine for the prescribed dose of 825 mg/m2 BID, morning and evening (total daily dose of 1650 mg/m2 ). Dosages will be rounded to the nearest 150 mg or 500 mg. Tablets should be swallowed with water within 30 minutes after a meal. Capecitabine will be started on the Monday of the first week of brachytherapy (day 1) and taken on weekdays (Monday through Friday) during weeks of brachytherapy only.~Administration of 5-FU should be only by the intravenous route taking care to avoid extravasation. Patients will receive 225 mg/m2/day, as a continuous venous infusion by a portable pump for the 3 weeks of treatment. The infusional 5-FU will be exchanged every 7 days."

Patients should complete the 2 quality of life questionnaires during their follow-up appointments. If they are unable to be seen in follow-up, they may complete the questionnaires at home and email or mail them back to the investigator. Should there be any incomplete or ambiguous answers, a follow-up phone call will be made by a member of the research team for clarification. Additionally, if the questionnaires have not been returned within 3 weeks after the time when they are due, a member of the research team will call the patient, and the questions will be completed over the phone.