HYPERBARIC OXYGEN TREATMENT OF CHRONIC REFRACTORY RADIATION PROCTITIS: A RANDOMIZED AND CONTROLLED DOUBLE-BLIND CROSSOVER TRIAL WITH LONG-TERM FOLLOW-UP

Purpose: Cancer patients who undergo radiotherapy remain at life-long risk of radiation-induced injury to normaltissues. We conducted a randomized, controlled, double-blind crossover trial with long-term follow-up to evaluatethe effectiveness of hyperbaric oxygen for refractory radiation proctitis.Methods and Materials: Patients with refractory radiation proctitis were randomized to hyperbaric oxygen at2.0 atmospheres absolute (Group 1) or air at 1.1 atmospheres absolute (Group 2). The sham patients were subse quently crossed to Group 1. All patients were re-evaluated by an investigator who was unaware of the treatmentallocation at 3 and 6 months and Years 1–5. The primary outcome measures were the late effects normal tissue subjective, objective, management, analytic (SOMA-LENT) score and standardized clinical assessment. Thesecondary outcome was the change in quality of life.Results: Of 226 patients assessed, 150 were entered in the study and 120 were evaluable. After the initial allocation,the mean SOMA-LENT score improved in both groups. For Group 1, the mean was lower (p = 0.0150) and theamount of improvement nearly twice as great (5.00 vs. 2.61, p = 0.0019). Similarly, Group 1 had a greater portionof responders per clinical assessment than did Group 2 (88.9% vs. 62.5%, respectively; p = 0.0009). Significanceimproved when the data were analyzed from an intention to treat perspective (p = 0.0006). Group 1 had a betterresult in the quality of life bowel bother subscale. These differences were abolished after the crossover.Conclusion: Hyperbaric oxygen therapy significantly improved the healing responses in patients with refractoryradiation proctitis, generating an absolute risk reduction of 32% (number needed to treat of 3) between the groupsafter the initial allocation. Other medical management requirements were discontinued, and advanc