TL;DR: HBOT for radiation injury follows well-established clinical protocols: treatments are typically delivered at 2.0 to 2.4 ATA for 90 minutes per session, once daily on weekdays, over a course of 30 to 60 sessions. This short guide explains what each protocol element means, why it matters, and what Canadian patients can expect from referral to completion.
Estimated reading time: 5 minutes
The Standard Protocol at a Glance
| Parameter | Standard Range | What It Means |
|---|---|---|
| Pressure | 2.0 to 2.4 ATA | 2 to 2.4 times normal atmospheric pressure |
| Oxygen | 100% medical-grade | Pure oxygen breathed throughout the session |
| Session length | 80 to 120 minutes | Includes compression, treatment time, and decompression |
| Frequency | Once daily, 5 days/week | Weekday treatments with weekends off |
| Total sessions | 30 to 60 | Varies by condition severity and response |
| Course duration | 6 to 12 weeks | Depending on session count and scheduling |
These parameters are consistent across major Canadian hospital programmes and align with recommendations from a 2026 clinically focused review published in CA: A Cancer Journal for Clinicians, which describes typical regimens of 2.0 to 2.5 ATA for 60 to 90 minutes, over 20 to 40 sessions.
During Daffodil Month, the Canadian Cancer Society’s annual cancer awareness campaign, we want cancer survivors to know that these protocols are well-established and available at hospitals and regulated facilities across Canada.
Why These Specific Parameters?
Pressure: 2.0 to 2.4 ATA
At 2.0 to 2.4 ATA, dissolved oxygen in blood plasma increases by approximately 10 to 15 times above normal. This is the range where the therapeutic benefits of angiogenesis (new blood vessel growth) and fibroblast activation are maximised without significantly increasing the risk of oxygen toxicity. A 2026 comparative study found that both 2.0 and 2.5 ATA protocols produced meaningful clinical improvement for radiation cystitis, though protocols varied between centres (ATA comparison study, 2026).
Session Length: 80 to 120 Minutes
Each session includes three phases: compression (5 to 10 minutes as the chamber pressurises), treatment time at full pressure (60 to 90 minutes of breathing 100% oxygen), and decompression (5 to 10 minutes as pressure returns to normal). Some protocols include scheduled air breaks where the patient breathes normal air for a few minutes to reduce the risk of oxygen toxicity.
A 2025 study evaluating a modified low-dose protocol (60 minutes at 2.4 ATA without air breaks vs. the standard 100 minutes with air breaks) found that both protocols achieved statistically significant improvements in radiation cystitis and proctitis symptoms, though the standard protocol produced better outcomes overall (Kumar et al., 2025).
Session Count: 30 to 60
The number of sessions depends on the type and severity of radiation injury:
- Osteoradionecrosis (prevention before dental work): 20 to 30 sessions pre-operatively, plus 10 post-operatively
- Soft tissue radiation necrosis: 30 to 40 sessions
- Radiation cystitis: 30 to 40 sessions (the RICH-ART trial used 30 to 40 sessions)
- Radiation proctitis: 40 to 60+ sessions (a 10-year study found that isolated bleeding tended to require at least 70 sessions)
Your hyperbaric medicine team will assess your response periodically and adjust the total number based on clinical improvement.
What Does a Typical Treatment Day Look Like?
- Arrival: You check in at the hyperbaric unit, change into cotton clothing (no synthetic fabrics for fire safety), and remove any personal items
- Pre-treatment check: A technician reviews your vitals and asks about any changes in your health since the last session
- Chamber entry: You enter a monoplace (single-person) or multiplace (room-sized) chamber depending on the facility
- Compression: The chamber pressurises over 5 to 10 minutes. You may feel pressure in your ears, similar to descending in an aeroplane. The technician will guide you through equalisation techniques
- Treatment: You breathe 100% oxygen for 60 to 90 minutes at treatment pressure. You can rest, read, or watch a screen (in many modern chambers)
- Decompression: The chamber slowly returns to normal pressure over 5 to 10 minutes
- Post-treatment: You can leave and resume normal activities. Most patients drive themselves to and from appointments
Is HBOT for Radiation Injury Covered in Canada?
Delayed radiation injury is one of the 14 conditions recognised under Health Canada’s device licensing framework and one of the most widely covered indications across Canadian provinces. OHIP covers treatment at hospital-based programmes in Ontario, Alberta Health covers it at hospital facilities, and MSP covers it at Vancouver General Hospital in British Columbia.
For a complete province-by-province breakdown, visit the Canada Hyperbarics coverage guide. To find a hospital or regulated facility near you, use the facility directory.
Frequently Asked Questions
Does HBOT hurt?
No. The treatment itself is painless. The most common sensation is pressure in the ears during compression, which resolves with simple equalisation techniques (swallowing, yawning, or the Valsalva manoeuvre). Some patients report mild fatigue after sessions.
Can I continue my other treatments during HBOT?
In most cases, yes. HBOT is typically used alongside other treatments, not as a replacement. Your hyperbaric medicine team will coordinate with your oncologist and other care providers. Certain medications may need adjustment during the treatment course.
How soon will I notice improvement?
Some patients notice improvement within the first 10 to 15 sessions. However, the full benefit of HBOT develops over the entire course because angiogenesis (new blood vessel growth) is a gradual biological process. The RICH-ART trial showed that improvements in radiation cystitis were sustained over 5 years (RICH-ART 5-year follow-up, 2025).
This Daffodil Month, Ask About HBOT
If you are a cancer survivor living with the lasting effects of radiation therapy, HBOT is a well-established treatment with standardised protocols available at hospitals and regulated facilities across Canada. Talk to your oncologist or family physician about a referral.
Find a hyperbaric facility near you across Canada.
This April, in recognition of Daffodil Month, Canada Hyperbarics is dedicated to helping cancer survivors understand and access treatments for the lasting effects of cancer therapy.
References
- Dejonckheere CS, et al. Hyperbaric oxygen therapy for chronic radiotherapy-related adverse effects: a clinically focused review. CA: A Cancer Journal for Clinicians. 2026. View in Canada Hyperbarics Research Database.
- Oscarsson N, et al. Radiation-induced cystitis treated with hyperbaric oxygen therapy (RICH-ART): long-term follow-up. EClinicalMedicine. 2025. View in Canada Hyperbarics Research Database.
- Kumar S, et al. Evaluation of the efficacy of modified low-dose HBO2 therapy. Undersea & Hyperbaric Medicine. 2025. View in Canada Hyperbarics Research Database.
- Monteiro AM, et al. The effectiveness of HBOT for managing radiation-induced proctitis: 10-year retrospective. Frontiers in Oncology. 2023. View in Canada Hyperbarics Research Database.
This content is for informational purposes only and does not constitute medical advice. Hyperbaric oxygen therapy should only be administered by qualified healthcare professionals in accredited facilities. Consult your physician or a certified hyperbaric medicine specialist for treatment decisions. Canada Hyperbarics is an independent educational resource and is not affiliated with any specific clinic or manufacturer.