What This Page Covers
A 2018 Cochrane review of 19 randomized trials (2,286 patients) found that HBOT combined with radiation therapy reduced 5-year mortality from head and neck cancers. A 2023 Cochrane review of 18 trials found HBOT reduced wound breakdown after head and neck surgery by 76% in irradiated patients. And a 2025 retrospective study of 45 cancer patients found no correlation between HBOT sessions and tumor recurrence. The oncology evidence is substantial and growing.
Beyond radiation injury, HBOT has been studied as a radiosensitizer during active cancer treatment. A 2018 Cochrane review of 19 randomized controlled trials involving 2,286 patients examined this evidence in detail1. This page serves as a navigation hub for all condition-specific articles on HBOT and cancer-related applications.
How HBOT Relates to Cancer Treatment
Radiation therapy works by generating reactive oxygen species (ROS) inside tumor cells, which damage DNA and trigger cell death. Tumors are frequently hypoxic (low-oxygen) at their core, which makes them less sensitive to radiation because oxygen is required for radiation damage to be maximally effective. This is a well-known mechanism in radiation oncology called the oxygen enhancement effect. HBOT, by saturating tissue with high-dose oxygen immediately before or during radiation, theoretically makes tumors more radiosensitive.
| Application | Evidence Level | Strength | FDA Status |
|---|---|---|---|
| Radiosensitizer (head & neck cancer) | High (Cochrane, 19 RCTs) | Moderate-Strong | Off-label |
| Radiosensitizer (cervical cancer) | High (Cochrane) | Weak – no clear benefit | Off-label |
| Radiosensitizer (bladder cancer) | High (Cochrane) | No benefit | Off-label |
| Late radiation injury – osteoradionecrosis | Moderate (Cochrane, registry) | Moderate | FDA-cleared |
| Late radiation injury – proctitis | Moderate (Cochrane) | Moderate | FDA-cleared |
| Late radiation injury – cystitis | Moderate | Weak-Moderate | FDA-cleared |
| Late radiation injury – neural tissue | Low-Moderate | No benefit | FDA-cleared |
| Direct anti-cancer therapy | Very low | Insufficient | Not established |
| Safety alongside cancer treatment | Low-Moderate | Safe – no tumor promotion | N/A |
HBOT as a Radiosensitizer
The 2018 Cochrane review analyzed 19 randomized trials across multiple cancer types1. The findings were site-specific:
- Head and neck cancer: 18% mortality reduction at 5 years (RR 0.82, 95% CI 0.69-0.98, high-quality evidence). 42% improvement in local tumor control at 3 months. 34% reduction in local recurrence at 1 year (RR 0.66, 95% CI 0.56-0.78). Number needed to treat: 11 for mortality benefit, 5 for recurrence.
- Cervical cancer: No clear benefit in mortality or recurrence
- Bladder cancer: No clear benefit
“According to a 2018 Cochrane review of 19 randomized trials involving 2,286 patients, HBOT combined with radiation therapy reduced 5-year mortality in head and neck cancer by 18% and decreased local tumor recurrence by 34% at one year.”
Bennett et al., 2018, Cochrane Database of Systematic Reviews
Important context: severe radiation reactions increased 2.6x with HBOT (RR 2.64), and seizure risk increased 6.8x (RR 6.76, moderate evidence). These radiosensitization trials were mostly conducted in the 1960s-1990s and have not been translated into current standard-of-care guidelines, partly because newer radiosensitizers and fractionation advances have overtaken the approach1.
Treating Radiation Injury (the Established Role)
The better-established role of HBOT is in treating the aftermath of radiation. Radiation damages the microvasculature of irradiated tissue, causing progressive hypoxia that leads to tissue death over time. HBOT promotes angiogenesis in these chronically hypoxic zones, restoring oxygen delivery and enabling healing that radiation damage had blocked.
A 2023 Cochrane review of 18 RCTs involving 1,071 participants confirmed benefits for specific injury types2:
- Osteoradionecrosis: improved mucosal coverage (RR 1.3, NNT=5)
- Radiation proctitis: improvement or cure (RR 1.72, NNT=5)
- Reduced wound dehiscence after head/neck surgery by 76% (RR 0.24)
- Pain reduction in osteoradionecrosis at 12 months
- No benefit for neural tissue radiation injury
radiation injury patients showed symptom improvement or resolution in 76.7%-92.6% of cases with HBOT
Niezgoda et al., 2016, Advances in Skin & Wound Care
A large registry study of 2,538 patients with radiation injuries found that symptoms improved or resolved in the majority of cases, with osteoradionecrosis showing the highest improvement rates. The five most commonly treated injuries were: osteoradionecrosis (33.4%), soft tissue radionecrosis (27.5%), radiation cystitis (18.6%), radiation proctitis (9.2%), and laryngeal radionecrosis (4.8%)3.
For a broader overview of HBOT research across all conditions, visit our HBOT research hub. Before starting any HBOT program, familiarize yourself with hyperbaric chamber side effects.
The Timeline of Radiation Injury
One of the most important things cancer patients and survivors need to understand about radiation injury is that it is not always immediate. Acute radiation injury occurs during or shortly after treatment and typically resolves with supportive care. Late radiation injury is a different phenomenon: it can manifest months or years after treatment ends, driven by progressive obliterative endarteritis (vascular occlusion) that radiation sets off in surrounding tissue.
A 2025 clinically focused review in CA: A Cancer Journal for Clinicians provided a comprehensive framework for clinical decision-making around HBOT for chronic radiotherapy-related adverse effects, highlighting gaps in patient selection, optimal protocols, and long-term outcomes5.
Courses of treatment for radiation injury typically involve 30 to 60 sessions depending on the site and severity, conducted in hard chambers at pressures of 2.0 to 2.4 ATA (atmospheres absolute).
Conditions Covered
HBOT and Cancer (General)
The broader question of whether HBOT has a role as an adjunctive cancer therapy is one of active research. Critically, HBOT does not promote tumor growth. A 2025 retrospective study of 45 cancer patients found no correlation between HBOT sessions and tumor recurrence or metastasis, and no HBOT-related complications were observed1. Our article on cancer support applications covers the current research landscape.
“HBOT does not promote cancer growth. A 2025 retrospective study of 45 cancer patients found no correlation between HBOT sessions and tumor recurrence or metastasis.”
Radiation Cystitis
Radiation cystitis, bladder inflammation caused by pelvic radiation for prostate, cervical, or bladder cancer, is one of the strongest indications for HBOT in oncology. The condition causes urinary frequency, urgency, hematuria, and significant pain. HBOT is approved by the UHMS for hemorrhagic radiation cystitis. A 2025 systematic review found moderate certainty evidence supporting HBOT for rectal complications and cystitis, though the recommendation remains case-by-case6. Our full article on HBOT for radiation cystitis covers protocols and expected outcomes.
Radiation Damage (General Soft Tissue and Bone)
Beyond the bladder, radiation can damage soft tissue and bone across any site within a treatment field. Dental procedures in irradiated jaw bone, surgery in irradiated abdominal or pelvic tissue, and skin breakdown in irradiated fields are all clinical scenarios where HBOT is routinely used at major cancer centers. Read our overview of HBOT for radiation damage. The radiation injury outcomes data page has the detailed clinical numbers.
“A 2023 Cochrane review of 18 trials found that HBOT reduced wound breakdown after head and neck surgery by 76% (RR 0.24) in irradiated patients, though evidence certainty remains low to moderate.”
Lin et al., 2023, Cochrane Database of Systematic Reviews
Osteoradionecrosis
Osteoradionecrosis of the jaw (ORNJ) is among the best-documented HBOT indications in medicine. When irradiated jawbone is exposed due to tooth extraction or spontaneous breakdown, the hypoxic tissue cannot heal normally. HBOT, in combination with surgery, dramatically improves healing rates and is considered standard of care at most major medical centers. Our article on HBOT for radiation injury provides a detailed breakdown of tissue-specific protocols.
Accessing HBOT as a Cancer Patient
For radiation injury indications, HBOT is most commonly available through hospital-based hyperbaric programs. Major academic medical centers and comprehensive cancer centers often have dedicated hyperbaric units. When seeking a facility, look for programs accredited by the UHMS and staffed by physicians with formal training in hyperbaric medicine.
What to Discuss With Your Oncologist
If you are a cancer patient or survivor considering HBOT, the first conversation must happen with your oncologist. While HBOT is generally safe and the concern that it stimulates cancer growth has not been substantiated by clinical data, your oncologist needs to review your specific cancer type, treatment history, and current status.
Also discuss access. HBOT for approved radiation injury indications is often covered by Medicare and many private insurers when properly documented. See our hyperbaric chamber cost guide and insurance coverage guide for more on coverage.
Related HBOT Guides
Radiation damage and cancer treatment side effects often develop into long-term chronic conditions. The guide on HBOT for chronic conditions covers related territory including autoimmune disease and systemic inflammation that can accompany cancer treatment. For a full overview of hyperbaric oxygen therapy including FDA-cleared indications and chamber types, see the complete hyperbaric chamber guide.
References
- Bennett MH, Feldmeier J, Smee R, Milross C. “Hyperbaric oxygenation for tumour sensitisation to radiotherapy.” Cochrane Database of Systematic Reviews, 2018;4:CD005007. DOI: 10.1002/14651858.CD005007.pub4
- Lin ZC, Bennett MH, Hawkins GC, et al. “Hyperbaric oxygen therapy for late radiation tissue injury.” Cochrane Database of Systematic Reviews, 2023;8:CD005005. DOI: 10.1002/14651858.CD005005.pub5
- Niezgoda JA, Serena T, Carter M. “Outcomes of radiation injuries using hyperbaric oxygen therapy: an observational cohort study.” Advances in Skin & Wound Care, 2016;29(1). DOI: 10.1097/01.ASW.0000473679.29537.c0
- Feldmeier J, Hampson N. “A systematic review of the literature reporting the application of hyperbaric oxygen prevention and treatment of delayed radiation injuries.” Undersea and Hyperbaric Medicine, 2002;29(1):4-30. PMID: 12507182
- Dejonckheere C, et al. “Hyperbaric oxygen therapy for chronic radiotherapy-related adverse effects: a clinically focused review.” CA: A Cancer Journal for Clinicians, 2025. DOI: 10.3322/caac.70058
- Eckert KA, Fife CE, Carter MJ. “Systematic review of hyperbaric oxygen for late radiation tissue injury (bowel, bladder).” Undersea & Hyperbaric Medicine, 2025. DOI: 10.22462/754
- El Hadji S, Teguh D, Ridderikhof M. “HBOT for late radiation tissue toxicity injury after head and neck cancer.” Radiation Oncology, 2025;20. DOI: 10.1186/s13014-025-02680-1
- Haffty BG, Hurley R, Peters LJ. “Radiation therapy with hyperbaric oxygen at 4 atmospheres pressure in the management of squamous cell carcinoma of the head and neck.” Cancer Journal from Scientific American, 1999;5(6):341-347. PMID: 10606475
- Mayer R, et al. “Hyperbaric oxygen and radiotherapy.” Strahlentherapie und Onkologie, 2005;181(2):113-123. DOI: 10.1007/s00066-005-1277-y
Medical Disclaimer
The content on BaricBoost.com is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Author
Seph Fontane Pennock is the founder of BaricBoost.com and Regenerated.com, a clinic directory for regenerative medicine serving 10,000+ providers across the United States. He previously built and sold PositivePsychology.com, which grew to 19 million users and became the largest evidence-based positive psychology resource on the web. Seph brings direct experience as an HBOT patient, having completed protocols at clinics across three continents while navigating mold illness, systemic inflammation, and autoimmune conditions. His treatment journey includes hyperbaric oxygen therapy, peptide protocols, NAD+ therapy, and consultations with specialists from Dubai to Cape Town to Mexico. This combination of entrepreneurial track record and lived patient experience shapes everything published on BaricBoost.com. Every article is grounded in peer-reviewed research, informed by real clinical encounters, and written for patients making high-stakes treatment decisions. Seph's focus is on bringing transparency, scientific rigor, and practical guidance to the hyperbaric oxygen therapy space.
