Outcomes of Hyperbaric Oxygen Therapy at 2.0 Versus 2.5 ATA for Hemorrhagic Radiation Cystitis

PURPOSE: Hemorrhagic radiation cystitis (HRC), a complication of pelvic radiation therapy, results from hypoxic and ischemic injury and causes urinary symptoms like hematuria, dysuria, frequency, urgency, and retention. Hyperbaric Oxygen Therapy (HBOT), where patients breathe 100% oxygen at increased atmospheric pressure, enhances tissue oxygenation, promoting neovascularization and reducing inflammation. The optimal pressure remains unclear, though pressures above 1.41 ATA are efficacious, with higher pressures increasing side effect risks. This study compares the efficacy and side effects of 2.0 versus 2.5 ATA therapy at two sites. MATERIALS AND METHODS: A retrospective chart review of 93 patients treated for HRC at two sites was conducted. Data on demographics, efficacy (symptom reduction), and side effects were analyzed using GraphPad Prism. Chi-squared and Mann-Whitney tests were used for statistical analysis. Mixed effects logistic regression models were used. RESULTS AND CONCLUSIONS: Fewer patients treated at 2.5 ATA experienced gross hematuria within 1-year post-therapy compared to those treated at 2.0 ATA (p < 0.05). However, time to hematuria recurrence showed no difference between the groups (10.2 vs. 9.6 months). No difference was observed in other urinary symptoms. Adverse events were increased at 2.5 ATA when analyzed with a mixed effects logistic regression model. Other treatment parameters, including treatment number and duration, were similar across groups. These findings suggest an association between 2.5 ATA treatment and lower rates of hematuria recurrence, but further randomized studies are necessary to determine causality. Future studies should also assess quality of life and explore variations in treatment protocol for efficacy and safety. CLINICAL TRIAL REGISTRATION: As this is a retrospective study, no clinical trial registration is necessary.