Hyperbaric Oxygen Therapy in Treating Long-Term Gastrointestinal Adverse Effects Caused by Radiation Therapy in Patients With Pelvic Cancer

OBJECTIVES: * To determine the clinical benefits of hyperbaric oxygen therapy in reducing dysfunction in patients with pelvic cancer developing iatrogenic gastrointestinal symptoms as a result of previous radical pelvic radiotherapy completed at least one year ago. OUTLINE: This is a multicenter study. Patients are stratified according to center and severity of symptoms (low vs high). Patients are randomized to 1 of 2 treatment arms. * Arm I (treatment group): Patients undergo hyperbaric oxygen therapy over 90 minutes, 5 days a week, for 8 weeks for a total of 40 treatments. Oxygen at 100% is breathed for 30 minutes, followed by a 5-minute "air break" and a further 30 minutes of breathing oxygen. A further 5-minute "air break" is followed by a further 30 minutes of breathing oxygen. During the final 10 minutes of oxygen breathing, the chamber is depressurized to ambient atmospheric pressure at a linear rate (14.2 kPa/min). * Arm II (control group): Patients undergo hyperbaric oxygen therapy over 90 minutes, 5 days a week, for 8 weeks for a total of 40 treatments. Oxygen at 21% is breathed for 30 minutes, followed by a 5-minute "air break" and a further 30 minutes of breathing oxygen. A further 5-minute "air break" is followed by a further 30 minutes of breathing oxygen. During the final 10 minutes of oxygen breathing, the chamber is depressurized to ambient atmospheric pressure at a linear rate (3 kPa/min). Tissue samples from rectal biopsies may be collected and analyzed. Patients complete questionnaires (Health Economics, Inflammatory Bowel Disease Questionnaire \[IBDQ\], EORTC Quality of Life \[QLQ\]-C30, and QLQ-CR38) at baseline and then at 3, 6, 9, and 12 months after the start of treatment. After completion of study treatment, patients are followed within 14 days and at 10 months.