Hyperbaric Oxygen Therapy Shows Lasting Relief for Radiation-Induced Cystitis: 5-Year RICH-ART Trial Results

Radiation-induced cystitis is a distressing complication that affects about 5–10% of patients who undergo pelvic radiotherapy for cancers such as prostate, bladder, or cervical cancer. Common symptoms include blood in the urine, urgency, frequency, and painful urination—all of which can severely impact a patient’s quality of life. While HBO₂ has been known to improve symptoms in the short term, evidence regarding its long-term efficacy has been limited.

The RICH-ART trial was a multicentre, open-label phase 2–3 study carried out across five Nordic hospitals in Sweden, Norway, Denmark, and Finland. It included patients aged between 18 and 80 years who had completed pelvic radiotherapy at least six months prior and had persistent bladder symptoms. Participants were randomly assigned to receive either HBO₂ therapy—30 to 40 daily sessions of 100% oxygen at high pressure—or standard care. Patients in the control group were later offered HBO₂.

The study led to the following findings:

• The five-year follow-up included 70 patients who had received hyperbaric oxygen therapy (HBO₂).
• Average urinary symptom scores improved by 18 points at six months post-treatment.
• At five years, the improvement remained stable, with a 19.1-point increase from baseline.
• Approximately 69% of patients (48 out of 70) experienced significant and sustained improvement, showing a mean increase of 22.9 points.
• The remaining 31% (22 patients) showed little to no symptom improvement even after five years.
• Only 12.8% of patients required repeat HBO₂ therapy due to the recurrence of symptoms.
• Adverse events were documented only during the HBO₂ treatment period.
• There were no new safety concerns during the long-term follow-up.

The findings not only reinforce the long-term efficacy of HBO₂ in managing chronic radiation cystitis but also underline the need for further research. “This is the first study to report five-year outcomes, offering vital data on the lasting impact of this therapy,” the authors stated. They suggest that HBO₂ could become a more widely adopted component of standard care, though further studies are needed to refine treatment protocols, assess economic viability, and identify predictors of treatment response.

The authors concluded, "The RICH-ART trial provides compelling evidence that HBO₂ can deliver durable symptom relief for patients suffering from radiation-induced bladder complications. As researchers continue to investigate optimal dosing and patient selection strategies, HBO₂ stands out as a promising and effective treatment option for improving long-term quality of life in this population."

Reference: https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(25)00146-4/fulltext