Hyperbaric oxygen therapy can relieve symptoms of late radiation cystitis in patients who underwent radiotherapy of the pelvic region for prostate cancer or other malignancies, according to the results of a new randomized trial. The trial results were published online ahead of print on September 16 in Lancet Oncology.
Late radiation cystitis is reported in 5% to 15% of patients after radiotherapy for prostate, rectal, or gynecologic cancers. Symptoms of late radiation cystitis include hematuria, increased urinary frequency and urgency, incontinence, and dysuria.
“The pathophysiology of late radiation cystitis is not completely understood,” wrote study authors led by Nicklas Oscarsson, MD, of the University of Gothenburg in Sweden. “Treatment of late radiation cystitis is challenging.”
Previous work suggested that hyperbaric oxygen therapy, where patients breathe pure oxygen at an increased ambient pressure in a hyperbaric chamber, could relieve some symptoms of late radiation cystitis, but prospective, randomized data was lacking. Researchers conducted a phase II-III randomized trial to provide more clarity on the use of this treatment.
A total of 87 patients were randomized at 5 Nordic university medical centers. The intent-to-treat population included 79 patients with symptoms of late radiation cystitis. They were randomized to receive either hyperbaric oxygen therapy (41 patients) or standard care (38 patients). Most patients in the cohort had prostate cancer (68%), followed by cervical cancer (23%); a small numbers of patients had rectal cancer, uterine cancer, or other malignancies.
The median time from radiotherapy to inclusion in the study was just over 4 years for both groups. The time from the debut of late radiation cystitis symptoms to inclusion was approximately 3 years.
The primary outcome was the urinary total score on the Expanded Prostate Index Composite Score (EPIC). From baseline to visit 4 (median of 234 days from randomization), patients in the hyperbaric oxygen therapy group had a chance in EPIC score of 17.8 points, compared with 7.7 points in the standard care group, for a difference of 10.1 points (P= 0.013). Significantly better improvements were seen with hyperbaric oxygen therapy for the EPIC subscores of bother and incontinence, as well as for EPIC bowel scores, while no other subscore differences reached statistical significance.
SF-36 scores also improved more with hyperbaric oxygen therapy than standard care, specifically with a significant improvement in general health (P= 0.0006).
A total of 17 patients (41%) in the hyperbaric oxygen therapy group experienced adverse events. Ear and vision problems relating to the oxygen therapy were “clearly related” to the therapy.
“Our study shows a beneficial effect of hyperbaric oxygen therapy for late radiation cystitis on several urological symptoms and quality of life in both female and male patients,” the authors concluded. “Further studies of microscopic changes and long-term effects are expected to answer some remaining questions.”
In an accompanying editorial, John J. Feldmeier, DO, of the University of Toledo Medical Center in Ohio, called this a “well-designed and very important trial.” He noted that the study did not address the optimal course of hyperbaric oxygen therapy including the best treatment pressure, optimal duration, and the appropriate number of treatments.
“It is important to remember that other so-called standard treatments are subject to disease recurrence and often need to be repeated,” he wrote. “Long-term follow-up in patients from this study will be essential to establish the durability of response to hyperbaric treatment and the need for additional treatments.”
MHjelleMDg K. Radiation-induced cystitis treated with hyperbaric oxygen therapy (RICH-ART): a randomised, controlled, phase 2–3 trial. The Lancet Oncology. https://www.sciencedirect.com/science/article/abs/pii/S1470204519304942. Published September 16, 2019.