Hyperbaric Oxygen Therapy: A Potential Solution for Radiation-Induced Hemorrhagic Cystitis

By Avi Verma MD(h)

Radiation therapy (RT) is a widely used treatment for pelvic cancers, including urological and
gynecological malignancies. While effective, RT can cause long-term complications, one of the
most concerning being radiation-induced hemorrhagic cystitis (RHC). RHC occurs when
radiation exposure damages the bladder, resulting in painful symptoms such as hematuria (blood in the urine), urinary frequency, urgency, and pelvic pain. The incidence of RHC ranges from 5% to 10% among cancer patients receiving RT to the pelvic region, with symptoms potentially emerging months to years after treatment.

Despite advancements in radiation techniques like Image-Guided Radiation Therapy (IGRT) and Intensity-Modulated Radiation Therapy (IMRT), which minimize damage to healthy tissue, the risk of late complications persists. RHC can lead to severe consequences, including life-threatening bleeding, and in extreme cases, major surgeries such as cystectomy (bladder
removal) may be required, with mortality rates as high as 44%.

Hyperbaric Oxygen Therapy (HBOT): A Promising Treatment

The primary non-invasive treatments for RHC include systemic medical therapies, intravesical instillation (directly applying medication into the bladder), and hyperbaric oxygen therapy (HBOT). While medications can reduce symptoms, they come with potential risks, such as thromboembolic events. HBOT, on the other hand, offers an innovative approach by administering pure oxygen in a pressurized chamber, promoting wound healing and reducing
pain through increased oxygen supply to damaged tissues.


HBOT has shown promise in improving symptoms of RHC. A recent meta-analysis, which reviewed 14 studies involving 556 patients, reported that 89.9% of patients experienced
symptom improvement after undergoing HBOT, with 54.9% achieving complete remission of
hematuria. While these results are encouraging, HBOT is not without its risks. Temporary side
effects, including ear barotrauma and reduced visual acuity, have been reported, although serious complications are rare.

Meta-Analysis: Evaluating the Effectiveness of HBOT

To further investigate the benefits and safety of HBOT, a systematic review and meta-analysis
was conducted. Researchers analyzed data from studies sourced from PubMed, Embase, and
Web of Science, with a focus on remission rates of RHC symptoms following HBOT treatment.
The pooled results from the meta-analysis revealed that HBOT significantly improves hematuria and other related symptoms, with 305 patients achieving complete remission and 195
experiencing partial remission.

However, the study also highlighted substantial heterogeneity among the included studies, partly due to the variety of study designs and treatment protocols. Most of the studies were
retrospective, which increased the risk of selection and performance biases. Despite this, the analysis demonstrated that HBOT remains a viable treatment option for RHC patients,
particularly those who have not responded well to other therapies.

Safety and Adverse Events

The overall risk of adverse events from HBOT was low, with minor side effects reported in only
5.2% of patients. The most common issues were temporary, such as visual disturbances and ear discomfort due to pressure changes. Serious side effects like seizures or pulmonary
complications were extremely rare, and no major adverse events were recorded in the studies
reviewed.

Future Directions: Exploring New Therapies

While HBOT offers a promising solution for RHC, ongoing research is exploring additional
treatments. For instance, vitamin E, an antioxidant, has shown potential in reducing RT-induced
fibrosis. Other pharmacological agents, such as the free-radical scavenger Edaravone, have
demonstrated efficacy in animal models of hemorrhagic cystitis. These therapies may
complement or enhance the effects of HBOT, offering hope for more comprehensive
management of RHC in the future.

Conclusion

Radiation-induced hemorrhagic cystitis is a debilitating condition that significantly affects the
quality of life of cancer patients. HBOT has emerged as a promising treatment option, offering
symptom relief and improved outcomes for many patients. Although further research is needed
to solidify its role in standard care, current evidence supports the use of HBOT as a safe and
effective therapy for RHC. As research continues, patients with RHC may soon have access to
even more innovative treatments, improving their quality of life and long-term outcomes.

This article is part of the IndoUS Tribune’s Health Corner series, focusing on the latest
developments in medical treatments.