To assess the clinical factors that affect the efficacy of hyperbaric oxygen (HBO2) therapy in treating radiation-induced hemorrhagic cystitis. HBO2 therapy is an effective treatment for radiation-induced hemorrhagic cystitis, with reported response rates ranging from 76% to 100%.

The data from patients with radiation-induced hemorrhagic cystitis treated at our institution between May 1988 and December 2001 were reviewed retrospectively. All patients received HBO2 therapy at 2.36 atm absolute pressure, with 90 minutes of 100% oxygen breathing per treatment. The outcome was assessed after at least 12 months of follow-up. We evaluated patient demographics, types of pelvic malignancy and radiotherapy, total radiation dose, onset and severity of hematuria, and prior intravesical management. Clinical improvement was defined as the absence of, or reduction in, macroscopic hematuria.

A total of 60 patients (55 men and 5 women), mean age 70 years, received an average of 33 HBO2 treatments (range 9 to 63). Of the 60 patients, 48 (80%) had either total or partial resolution of hematuria. When treated within 6 months of hematuria onset, 96% (27 of 28) had complete or partial symptomatic resolution (P = 0.003). All 11 patients with previous clot retention had clinical improvement if treated within 6 months of hematuria onset (P = 0.007). Prior intravesical chemical instillation did not affect the clinical outcome. Patients who had undergone primary, adjuvant, or salvage external beam pelvic radiotherapy showed response rates of 81%, 83%, and 78%, respectively (P = 0.950).

Our results show that delivery of HBO2 therapy within 6 months of hematuria onset is associated with a greater therapeutic response rate. Treatment efficacy was independent of prior intravesical therapy and the timing of radiotherapy.