A comparison of two hyperbaric oxygen regimens: 2.0 ATA for 120 minutes to 2.4 ATA for 90 minutes in treating radiation-induced cystitis Are these regimens equivalent?

Introduction: Hyperbaric oxygen dosing variations exist in radiation cystitis treatment. The objectives of this study were to compare response and safety rates among patients with radiation cystitis treated with different protocols: 2.0 ATA (atmospheres absolute) for 120 minutes at the University of Pennsylvania; and 2.4 ATA for 90 minutes at Hennepin Healthcare. Materials and Methods: Retrospective chart review of radiation cystitis patients treated with hyperbaric oxygen at the University of Pennsylvania (January 2010-December 2018) and Hennepin Healthcare Minnesota (January 2014-December 2018). Primary outcome was response to treatment. Complications were limited to hyperbaric-related conditions. Regression analysis was performed with ordinal logistic regression and binary logistic regression. Result: 126 patients were included in the analysis (2.0 ATA: 66, 2.4 ATA: 60). Overall response rate was 75.4% (good) and was not significantly different between protocols (good response: 2.0 ATA 72.7% vs. 2.4 ATA 78.3% p=0.74). The 2.0 ATA group required additional treatments [2.0 ATA: 45.45 ± 14.5 vs. 2.4 ATA: 40.03 ± 9.7, p<0.05]. 6.1% (2.0 ATA) and 13.3% (2.4 ATA) required tympanostomy tube placement or needle myringotomy for otic barotrauma (p=0.22). Transfusion was associated with poorer outcomes (p<0.05). Conclusion: Both groups - 2.0 ATA and 2.4 ATA - had similar response and complication rates. Blood transfusion is a negative prognostic factor for treatment outcome.

Esophageal Stricture Following Radiation, Concurrent Immunochemotherapy, Treated With Hyperbaric Oxygen and Dilation.

Low-dose palliative radiation may offer symptomatic relief in patients with spinal metastases from primary renal cell cancer and is unlikely to result in radiation injury. Patients with advanced malignancy requiring palliative radiation are often also receiving chemotherapy. Synergistic adverse effects resulting from combined palliative radiation and novel antiprogrammed cell death-1 (anti-PD 1) and/or multityrosine kinase inhibitors are rare. We report about a 60-year-old woman with metastatic clear-cell renal cancer, status post-left nephrectomy, with debilitating mid-back pain from metastatic tumor burden and foraminal nerve compression. Her chemotherapeutic regimen was repeatedly altered because of progression of disease until she was maintained on the anti-PD 1 checkpoint inhibitor, nivolumab. She received palliative radiation to her thoracic spine over a 2-week period, and nivolumab was then switched to cabozantinib midway through a course of palliative radiation. The patient rapidly developed severe esophagitis, progressing to esophageal stricture, and required placement of a percutaneous endoscopic gastrostomy tube. She was successfully treated with serial esophageal dilation and hyperbaric oxygen treatments to diminish inflammation and improve tissue vascularity. Concurrent use of anti-PD 1 and/or multityrosine kinase drugs may accelerate development of radiation injury regardless of radiation dosage. Radiation-induced esophageal stricture was managed successfully in this patient with serial esophageal dilation and adjuvant hyperbaric oxygen.