Efficacy, tolerance and predictors of response to the treatment with hyperbaric oxygen therapy for patients with hemorrhagic radiation cystitis

Objectives: The aim was to study the efficacy and tolerance in patients with haemorrhagic radiation-induced cystitis (HRC) treated with hyperbaric oxygen therapy (HOT) and analyze which factors were related to the response to the treatment. Material and methods: We performed a retrospective cohort study of patients treated with HOT for HRC symptoms in a provin-cial referral centre from 2010 to 2020. We evaluated clinical response to treatment, number of hospitalizations due to HRC and subjective response using the PGI-I questionnaire. Results: We treated 52 patients, with a median of 30 sessions, during 6 months and 40 months (6-68 months) of follow-up. 69.2% of patients responded completely and 21,2% partially. The 53.2% of patients improved before the first 10 sessions. Reduction of hospitalizations/per year due to haematuria from 2.8 to 1.1 (p=0,001). The 73,5% of patients stated that they were "very much better" or "much better" after treatment. During the follow-up, 15.4% of patients had recurrence of HRC. 9.6% of the patients required salvage cystectomy. The patients with a highest RTOG-EORTC scale had more risk to still with symptoms (OR 3.01 (IC95 1.48 - 6.16). All patients were able to complete the proposed treatment plan with good tolerance to HOT. Conclusions: These results show the clinical benefit of HOT in the treatment of HRC, with a reduction of the number of hospi-talizations and a subjective improvement.