AML-410: Efficacy of Hyperbaric Oxygen Therapy in Hematologic Malignancy Patients: A Single Comprehensive Cancer Center Retrospective Review of 50 Patients

Introduction: Hyperbaric oxygen therapy (HBO) is approved for difficult-to-treat tissue injury. It also been used as a second-line treatment for refractory infection in hematologic malignancies. However, data on the efficacy of HBO in such population are limited. Here, we reviewed our single-center experience of HBO used in patients with hematologic malignancies. Methods: We identified patients undergoing HBO treatment by insurance authorization data between December 2012 and October 2019 at MD Anderson Cancer Center. Patients with a diagnosis of hematologic malignancies with or without history of stem-cell transplant were included. Clinical and demographic data were collected by retrospective chart review. Results: A total of 50 patients were included: 26 (52%) patients had Acute Myeloid Leukemia, 31 (62%) patients had received an SCT, and 34 (68%) patients had active disease, of whom 28 (56%) had relapsed/refractory disease. The most common infections were: 19 (38%) BK cystitis and 17 (34%) fungal sinusitis. Median number of HBO sessions was 5 (range 1–60), and median HBO duration was 17 days (range 0–109). All patients received initial HBO in the hospital; 25 (50%) patients were discharged from hospital at either completion of HBO or after transition to outpatient treatment. Sixteen (32%) patients were discharged to hospice, and 8 (16%) patients died during the hospitalization. Ninety-day and 1-year mortality were high at 52% and 78%, respectively. Median survival was 3.1 months. Patients with BK cystitis were less likely to respond to HBO (odds ratio 0.16, p=.004). Eight patients had response to HBO and achieved remission of infection at last follow-up. These patients had a higher proportion (50%) of underlying disease in remission, compared to 29% in rest of patients (n=42). The treatment indications in the responding group were 2 BK cystitis, 2 fungal sinusitis, 2 cellulitis, and 2 non-BK cystitis. Other patient characteristics were similar to the rest of the patients. Patients with response/infection remission had better survival with HR 0.18 (95% CI .063–.529, p=.002). Conclusion: A small subset of patients with hematologic malignancies, 16% in our study, had meaningful recovery from infection after HBO treatment. In our experience, patients whose underlying malignancy was in remission and patients with non-BK infection had better outcomes. Additional studies are needed to better identify the population who would benefit from HBO.