Radiation therapy saves lives. But for some cancer survivors, the story doesn't end when treatment does. Months or even years later, a new problem appears: a jaw that won't heal after a dental procedure, bladder irritation and bleeding, bowel urgency and pain, or skin and tissue that feels tight, fragile, or slow to repair. If that's you, it can feel unfair to be dealing with something new long after the hard part was supposed to be over.

The good news is that this is a recognized problem with recognized options. Hyperbaric oxygen therapy (HBOT) is one of the established medical uses for what doctors call late radiation tissue injury. Here's what that means, what the research shows, and what to ask before starting.

Why Radiation Can Cause Problems Years Later

Radiation is aimed at a tumor, but healthy tissue in the path of the beam is affected too. Over time, radiation can damage small blood vessels in that tissue, reducing blood flow and oxygen supply. Tissue that is chronically short on oxygen heals poorly, becomes fragile, and can break down, sometimes triggered by something as ordinary as a tooth extraction or minor injury.

Common late effects include:

• Osteoradionecrosis (ORN): bone that doesn't heal after radiation, most often in the jaw

• Radiation cystitis: bladder inflammation and bleeding after pelvic radiation

• Radiation proctitis: bowel inflammation and bleeding after pelvic radiation

• Soft tissue injury: skin and tissue breakdown, fibrosis, and wounds that won't close in irradiated areas

These can appear months to years after treatment, which is why they're often a surprise.

How HBOT Fits In

HBOT targets the underlying problem: oxygen-starved tissue. Inside the chamber, you breathe near-100% oxygen under pressure, which dissolves far more oxygen into the blood plasma than normal breathing can. That helps oxygen reach damaged tissue, supports the growth of new blood vessels, and gives the body what it needs to rebuild. It's the same oxygen-delivery logic behind HBOT's use for slow-healing wounds.

What the Research Shows

The evidence differs by condition, so it's worth being specific.

Radiation cystitis (bladder). This is among the strongest areas. In a randomized trial known as RICH-ART, patients receiving HBOT improved more on urinary symptom scores than those receiving standard care, and the benefit was still present five years later.

Radiation proctitis (bowel). Results are more mixed. One sham-controlled trial showed benefit, while another was negative, and clinical guidelines do support HBOT as an option for this condition.

Jaw osteoradionecrosis. HBOT is recommended as an add-on to surgery in severe cases, and analyses of the trials suggest better odds of bone healing, although individual studies have been small. Using HBOT preventively before dental extractions has not been shown to lower the risk of ORN in a trial, so it isn't recommended for that purpose.

Chest wall, breast, and lymphedema effects. One trial did not meet its main pain goal, partly because many patients struggled with the time commitment. Some patients who completed treatment showed less fibrosis and pain, but that needs more study.

Nerve and brain tissue. A large review of controlled trials found no clear benefit for established radiation injury to neural tissue.

In short, HBOT has solid support for some late radiation injuries and weaker support for others. A good provider will tell you which category yours falls into.

What Treatment Typically Looks Like

Courses for late radiation injury tend to be long. Published protocols commonly involve around 30 to 40 sessions for bladder or bowel injury, and a pre- and post-surgery series for severe jaw injury. Sessions are usually about 90 minutes. Improvement can build gradually and sometimes becomes noticeable weeks after the last session. Earlier treatment tends to work better. In bladder injury, for example, outcomes appear better when HBOT starts within months of symptoms beginning.

Safety Questions to Ask First

HBOT is generally well tolerated, but screening matters, and it matters more if you've had cancer treatment:

• Coordinate with your oncology team. Certain chemotherapy drugs, including bleomycin, doxorubicin, and cisplatin, can interact with HBOT, and some require waiting periods between treatments. Newer immunotherapies are less well studied, so close monitoring is advised.

• Review your medications and medical history, including lung disease, asthma, and any implanted devices.

• Discuss your cancer status. Whether HBOT is appropriate depends on your individual situation and your oncologist's input.

• Know the common side effects. Ear pressure is the most common, with temporary nearsightedness and fatigue less so. Serious reactions are rare.

Practical Tips if You've Had Radiation

• Tell every dentist about prior head or neck radiation before any extraction or dental surgery.

• Report new symptoms early: blood in urine or stool, persistent jaw pain, exposed bone, or wounds that aren't healing.

• Don't assume it's "just a side effect you have to live with." Ask your care team whether HBOT is appropriate for you.

The Bottom Line

Late radiation injury is real, it's often misunderstood, and it's one of the better-supported uses of hyperbaric oxygen. It isn't a cure-all, and the strength of the evidence depends on the condition, which is why an individual evaluation matters.

Dealing with side effects from past radiation treatment? Schedule a consultation with Bay Area Hyperbarics team to review your history and treatment records, and find out whether HBOT could be a safe, appropriate part of your recovery, in coordination with your oncology team.