Glioblastoma is NOT on Health Canada's 14 recognised hyperbaric oxygen therapy indications and HBOT is NOT a standard or publicly funded treatment for the tumour itself in Canada. Research interest focuses on HBOT as a radiosensitiser delivered immediately before each radiotherapy fraction; the published evidence is preliminary, comes mostly from small early-phase Japanese trials, and has not produced a Phase III survival benefit. The Health Canada-recognised hyperbaric use in this patient population is for delayed radiation injury to the brain (radiation necrosis) following cranial radiotherapy, which IS publicly funded at all 11 Canadian hospital hyperbaric programmes.
Quick Answer
Does HBOT help glioblastoma? Glioblastoma is NOT on Health Canada's 14 recognised hyperbaric oxygen therapy indications and HBOT is NOT a standard or publicly funded treatment for the tumour itself in Canada. Research interest focuses on HBOT as a radiosensitiser delivered immediately before each radiotherapy fraction; the published evidence is preliminary, comes mostly from small early-phase Japanese trials, and has not produced a Phase III survival benefit. The Health Canada-recognised hyperbaric use in this patient population is for delayed radiation injury to the brain (radiation necrosis) following cranial radiotherapy, which IS publicly funded at all 11 Canadian hospital hyperbaric programmes.
Glioblastoma multiforme (GBM, World Health Organization grade IV glioma) is the most common and most aggressive primary brain tumour in adults. Approximately 1,000 to 1,200 new cases are diagnosed in Canada each year. Standard first-line treatment is the Stupp protocol: maximal safe surgical resection of the primary tumour, followed by concurrent temozolomide chemoradiotherapy (60 Gy in 30 fractions plus daily oral temozolomide), followed by adjuvant temozolomide for six monthly cycles. Despite this multimodal approach, median overall survival remains approximately 15 months from diagnosis with a five-year survival of approximately 5 to 7 percent, making glioblastoma one of the most lethal cancers in adults.
The biological basis for hyperbaric-medicine interest in glioblastoma is tumour hypoxia. The aggressive growth of GBM outpaces neovascularisation, creating regions of severe tissue hypoxia within the tumour mass. Hypoxic tumour cells are two to three times more radioresistant than well-oxygenated cells (the oxygen enhancement ratio for ionising radiation is approximately 2.5 to 3.0 at extreme hypoxia), and they also resist many chemotherapies. The hypoxic tumour microenvironment also drives selection for more aggressive cell phenotypes through HIF-1α signalling. Multiple research groups have therefore asked whether transiently raising tumour oxygenation immediately before radiation (or potentially before chemotherapy) can improve treatment outcomes.
Hyperbaric oxygen therapy enters the glioblastoma conversation in two completely distinct ways that patients and clinicians often conflate but that need to be kept separate.
First, as an experimental radiosensitiser given immediately before each radiotherapy fraction. The rationale is that HBOT acutely and transiently raises tumour tissue oxygen tension above the threshold at which ionising radiation can generate the DNA-damaging free radicals that produce its tumour-killing effect. The intervention is investigational: a small set of early-phase trials (predominantly from Japanese centres, including the Kohshi group; <a href='https://pubmed.ncbi.nlm.nih.gov/8898978/' target='_blank' rel='noopener' class='text-pressure-teal hover:underline'>PMID 8898978</a>, 17120158) has tested this approach with mixed and inconclusive results, and no large randomised Phase III trial has confirmed an overall-survival benefit.
Second, as a Health Canada-recognised, publicly funded treatment for delayed radiation injury to the brain (radiation necrosis) in patients who have completed cranial radiotherapy. This is a completely different clinical scenario: the tumour has already been treated, and the late-effect target tissue is the irradiated normal brain that is now showing progressive vascular failure and necrosis months to years after radiation. This use of HBOT falls under UHMS recognised condition #11 (Delayed Radiation Injury) and is covered by every Canadian provincial health insurance plan at the 11 hospital hyperbaric programmes.
The mechanistic rationale for HBOT in glioblastoma differs sharply between the two distinct clinical applications.
For HBOT as a radiosensitiser (investigational, tumour-directed), the mechanism is acute and transient tumour reoxygenation immediately before each radiotherapy fraction. Inside the chamber at 2.0 to 2.4 ATA on 100 percent oxygen, plasma oxygen content rises 10- to 15-fold, raising tumour pO2 in previously hypoxic tumour regions to therapeutic levels. The patient is decompressed and immediately transported to the linear accelerator suite while tumour oxygenation remains transiently elevated (the time-window is short, typically 15 to 30 minutes). The radiation dose is then delivered into the now-better-oxygenated tumour, theoretically generating more DNA-damaging free radicals and producing greater tumour-cell kill. This is the conceptual basis underlying the Japanese small-trial experience and remains the active research question. Practical challenges (chamber-to-radiotherapy logistics, patient throughput, chamber oxygen safety with adjacent radiation equipment) have limited adoption in routine clinical practice.
For HBOT in delayed brain radiation necrosis (recognised indication), the mechanism follows the standard model for late radiation tissue injury. The radiation-induced obliterative endarteritis of small cerebral vessels produces progressive tissue hypoxia, fibrosis, and necrosis in the irradiated normal brain. Repeated HBOT sessions stimulate angiogenesis through VEGF release, raise tissue oxygenation in the hypocellular hypovascular irradiated bed, restore fibroblast function, and reduce late-effect inflammation. The biological response builds over 30 to 60 sessions and the new vascular network persists after treatment ends, providing the durable benefit seen in the published radiation-injury literature including the Bennett 2016 Cochrane Review.
These two mechanisms have different time-courses (acute single-session vs. cumulative over weeks), different anatomical targets (tumour vs. normal brain late effect), different evidence bases (preliminary tumour-directed RCTs vs. established radiation-injury Cochrane evidence), and different Canadian regulatory and funding status (off-label / research vs. publicly funded).
Typical Treatment Protocol
For tumour-directed HBOT as a radiosensitiser (off-label, research only in Canada): published trial protocols have used 2.0 to 2.5 ATA on 100 percent oxygen for 60 to 90 minutes per session, delivered immediately before each radiotherapy fraction (60 Gy in 30 fractions standard Stupp protocol), with the patient transported from the chamber to the linear accelerator suite within 15 to 30 minutes of decompression. This is investigational. There is no standardised Canadian protocol because the indication is not Health Canada-recognised and is not publicly funded for tumour-directed use. For brain radiation necrosis (recognised indication): the standard protocol is 2.0 to 2.4 ATA on 100 percent oxygen for 90 minutes per session, 30 to 60 total sessions, often combined with corticosteroids and bevacizumab. Course extension to 60 sessions is common for cases with significant mass effect or persistent symptoms. Glioblastoma patients on active chemoradiotherapy have specific drug-interaction considerations, particularly with concurrent temozolomide. Timing and interactions should be reviewed by the treating neuro-oncology team. Bleomycin (rare in GBM but possible in other CNS tumours) and disulfiram remain absolute contraindications.
Investigational
Off-label or off-list in Canada; not Health Canada-recognised
Glioblastoma is NOT on Health Canada's 14 recognised conditions list for HBOT. Tumour-directed HBOT is not a standard or publicly funded treatment for GBM in Canada.
The biological rationale for HBOT as a radiosensitiser is well-established: hypoxic tumour cells are two to three times more radioresistant than well-oxygenated cells (oxygen enhancement ratio approximately 2.5 to 3.0 at extreme hypoxia). Transiently raising tumour pO2 immediately before radiation is the conceptual basis, but Phase III evidence is lacking.
The published trial evidence for tumour-directed HBOT comes predominantly from small early-phase Japanese trials. The Kohshi 1996 controlled study (PMID 8898978) compared 9 patients receiving HBOT plus radiotherapy with 12 receiving radiotherapy alone and reported greater tumour regression in the HBOT arm. The Kohshi 2007 follow-up (PMID 17120158) added HBOT to stereotactic radiotherapy in 25 patients with recurrent high-grade glioma (14 anaplastic astrocytoma, 11 glioblastoma) and reported a median survival of 11 months in the glioblastoma sub-group. Sample sizes are modest across the trial set, results are mixed, and no Phase III randomised trial has confirmed an overall-survival benefit.
Distinct from tumour-directed use, brain radiation necrosis (delayed radiation injury to the brain) following cranial radiotherapy IS a Health Canada-recognised hyperbaric indication under UHMS condition #11 and is publicly funded at all 11 Canadian hospital hyperbaric programmes.
The Bennett 2016 Cochrane Review (PMID 27123955) of HBOT for late radiation tissue injury supports HBOT for delayed radiation effects across multiple anatomical sites but does not address tumour-directed use in active glioblastoma.
The Princess Margaret Cancer Centre / UHN in Toronto is the leading Canadian neuro-oncology centre for HBOT integration in radiation necrosis. Hamilton General Hospital, The Ottawa Hospital, Vancouver General Hospital, Misericordia Edmonton, and Foothills Calgary also have active radiation-necrosis HBOT practice.
Patients should distinguish carefully between research-protocol HBOT for the tumour itself (preliminary, investigational, not publicly funded) and standard HBOT for late radiation complications (recognised, evidence-based, publicly funded).
No high-quality RCT evidence currently supports HBOT as a survival-extending treatment for glioblastoma. Patients seeking tumour-directed HBOT should be honest with themselves and their families about the preliminary nature of the evidence and should prefer trial enrolment over self-pay use at private clinics.
Highest-evidence-tier studies tagged to this condition in the Canada Hyperbarics research database, ranked by evidence tier (1 = meta-analysis or RCT, 2 = cohort, 3 = case series), most recent first.
Cancer medicine · 2023 · Systematic Review
No Shinkei Geka · 2011 · Review
For tumour-directed radiosensitisation HBOT, the practical reality in Canada is that this is generally not available outside of a clinical trial. The neuro-oncology team can assess eligibility for any active research protocol, but enrolment is rare and is typically limited to specific tertiary academic centres. Patients seeking this option on a self-pay basis at private clinics should be aware that no Canadian private clinic operates the chamber-to-linear-accelerator logistics that the Japanese protocols require, so any private-pay HBOT delivered "alongside" radiotherapy would be temporally disconnected from the radiation fractions and therefore would not deliver the radiosensitisation rationale.
For brain radiation necrosis (the recognised indication), patients are typically referred to a hospital hyperbaric programme by their neuro-oncologist, radiation oncologist, or neurosurgeon after the diagnosis is confirmed on serial MRI. The hyperbaric medicine team confirms eligibility, reviews imaging, screens for absolute and relative contraindications, and books the treatment course. Daily sessions begin within two to six weeks of consultation, with timing partly driven by inter-disciplinary coordination with neuro-oncology. Total course is typically 30 to 60 sessions over six to twelve weeks. Response is followed by serial MRI and clinical assessment. Most patients tolerate the course well; common side effects are temporary near-sightedness during treatment, ear barotrauma (managed with pressure-equalisation), and mild fatigue.
Tumour-directed HBOT for glioblastoma is generally not available in Canada outside of an active clinical trial. As of April 2026, no Canadian academic centre routinely offers chamber-immediately-before-radiotherapy HBOT as part of standard glioblastoma management, and no Canadian phase II or III trial of this approach is in current recruiting status. Patients interested in research-protocol radiosensitisation HBOT should discuss with their neuro-oncology team and consult ClinicalTrials.gov for any newly opened international or Canadian trials.
Delayed radiation injury to the brain (radiation necrosis) is publicly funded as a Health Canada-recognised indication at all 11 hospital hyperbaric programmes in Canada. OHIP, MSP, AHCIP, RAMQ, MSI, MCP, and Saskatchewan Health all cover treatment. Referral pathway is neuro-oncology, radiation oncology, or neurosurgery referring to the nearest hospital hyperbaric programme. The Princess Margaret Cancer Centre / UHN in Toronto is among the leading Canadian centres for HBOT research in radiation injury, particularly brain radiation necrosis, and has the strongest neuro-oncology HBOT integration in the country. Other centres with active radiation-necrosis HBOT practice include Hamilton General Hospital, The Ottawa Hospital, Vancouver General Hospital, Misericordia Edmonton, and Foothills Calgary.
For patients in provinces or territories without an in-province hospital programme (Manitoba, New Brunswick, Prince Edward Island, Yukon, Northwest Territories, Nunavut), publicly funded HBOT for brain radiation necrosis is accessed through inter-provincial referral coordinated by the neuro-oncology team. Inter-provincial billing arrangements typically cover the medically necessary treatment cost; travel and accommodation are usually the patient's responsibility unless the home province operates a medical-travel assistance programme.
Glioblastoma is not on Health Canada's 14 recognised conditions list for hyperbaric oxygen therapy and is not publicly funded for this indication by any provincial health insurance plan. The 11 Canadian hospital hyperbaric programmes (located in Ontario, Quebec, British Columbia, Alberta, Nova Scotia, Newfoundland and Labrador, and Saskatchewan) treat the 14 Health Canada-recognised conditions only; they do not provide HBOT for Glioblastoma outside of an active clinical trial. Patients seeking HBOT for Glioblastoma are limited to private clinics on a self-pay basis, or to enrolment in a Canadian recruiting trial. Use the links below for province-specific context on the broader 14-condition pathway.
Hospital + Private
OHIP (Ontario Health Insurance Plan)
Hospital Only
MSP (Medical Services Plan)
Hospital + Private
Alberta Health / AHCIP
Hospital Only
RAMQ
Disrupted
Saskatchewan Health Authority
No Hospital Chamber
Manitoba Health
Hospital Only
MSI (Medical Services Insurance)
No Hospital Chamber
Medicare NB
Hospital Only
MCP (Medical Care Plan)
Out-of-Province Referral
Health PEI
Out-of-Province Referral
Yukon Health and Social Services
Out-of-Province Referral
NWT Health and Social Services
Out-of-Province Referral
Nunavut Department of Health
For acute or emergency presentations of Glioblastoma, call 911 first. The receiving emergency department coordinates urgent transfer to the nearest hospital hyperbaric programme through the relevant provincial transfer network (CritiCall Ontario at 1-800-668-4357, BC Patient Transfer Network, EHS Nova Scotia, or equivalent). For diving-related emergencies, the Divers Alert Network (DAN) emergency hotline is 1-919-684-9111.
Absolute contraindications to HBOT include untreated pneumothorax (because trapped intrathoracic air expands on decompression and can cause tension pneumothorax), concurrent bleomycin chemotherapy (because hyperbaric oxygen can trigger or accelerate oxygen-induced pulmonary fibrosis), and concurrent disulfiram (because it inhibits superoxide dismutase, the enzyme that neutralises hyperbaric-oxygen-generated free radicals). Prior bleomycin exposure with documented pulmonary clearance is a relative contraindication that requires individualised pulmonary-function review before HBOT. For glioblastoma patients on active chemoradiotherapy, the timing and interaction with concurrent temozolomide should be reviewed by the treating oncology team. Severely raised intracranial pressure with impending herniation is a relative contraindication and requires individual judgement; the brief hyperoxic vasoconstriction during HBOT can actually reduce ICP in many cases, but uncontrolled malignant ICP requires neurosurgical decompression first. Active tumour progression with mass effect is not a contraindication to HBOT for radiation necrosis but is a relative caution that the multidisciplinary team weighs against expected benefit. Claustrophobia, severe COPD with bullous lung disease, uncontrolled seizure disorder (often present in GBM patients), and uncontrolled hypertension are additional relative contraindications that require individual judgement.
Glioblastoma is not on Health Canada's 14 recognised conditions for HBOT. HBOT is NOT a standard treatment for the tumour itself in Canada and is not publicly funded for this purpose. Some research has explored HBOT as a radiosensitiser delivered before radiotherapy, but this is generally available only on a research-protocol basis at specific tertiary academic centres. Self-pay private-clinic HBOT \"alongside\" radiotherapy does not deliver the radiosensitisation effect because the chamber-to-linear-accelerator timing required by the published protocols is not operationally available outside a hospital research setting.
Yes. Delayed radiation injury to the brain (radiation necrosis) is one of Health Canada's 14 recognised hyperbaric oxygen therapy conditions and is publicly funded at all 11 hospital hyperbaric programmes across Canada. This is a separate, established use of HBOT, distinct from any tumour-directed application. Standard course is 30 to 60 sessions at 2.0 to 2.4 ATA, often combined with corticosteroids and bevacizumab, with response tracked by serial MRI. The Princess Margaret Cancer Centre / UHN in Toronto leads Canadian practice in this area.
Small early-phase trials, predominantly from Japanese centres (Kohshi and others; <a href="https://pubmed.ncbi.nlm.nih.gov/8898978/" target="_blank" rel="noopener" class="text-pressure-teal hover:underline">PMID 8898978</a>, 17120158), have explored HBOT immediately before each radiotherapy fraction on the rationale that better oxygenation makes radiation more effective. Results are mixed, sample sizes are small, and no Phase III randomised trial has confirmed an overall-survival benefit. The 2016 Bennett Cochrane Review of late radiation tissue injury supports HBOT for delayed radiation effects but does not address tumour-directed use in active glioblastoma. Be cautious of any commercial source claiming HBOT extends survival in glioblastoma; the evidence does not support that claim.
This is a question for the treating neuro-oncology team. Temozolomide is the cornerstone of the Stupp protocol for glioblastoma and is given concurrently with radiation and as adjuvant therapy. HBOT timing and interactions with active temozolomide need careful coordination. For brain radiation necrosis HBOT (the recognised indication), treatment is typically delivered after the active chemoradiotherapy phase has completed, so the temozolomide-HBOT timing question is less acute.
As of April 2026, no Canadian Phase II or III trial of HBOT as a radiosensitiser in glioblastoma is in current recruiting status. International trials are listed at ClinicalTrials.gov; the Canadian neuro-oncology research network can advise on cross-border trial enrolment. Discuss with your neuro-oncology team and consult ClinicalTrials.gov directly for the most current trial status.
Be honest with yourself and your family about the preliminary state of the evidence. Self-pay HBOT for glioblastoma at private clinics typically costs $6,000 to $16,000 for a 40-session course, does not deliver the radiosensitisation rationale (because the chamber-to-radiotherapy timing is operationally infeasible outside a hospital research setting), and does not have Phase III evidence supporting a survival benefit. If you are considering trying additional therapies, prioritise trial enrolment over self-pay use, and discuss the financial trade-offs with your family in the context of the overall prognosis. The Health Canada-recognised use of HBOT in this population (brain radiation necrosis after radiotherapy) is publicly funded and is the place where HBOT has the strongest evidence base for glioblastoma patients.
At all 11 hospital hyperbaric programmes across seven provinces (Ontario, Quebec, British Columbia, Alberta, Nova Scotia, Newfoundland and Labrador, and Saskatchewan), with referral from neuro-oncology, radiation oncology, or neurosurgery. The Princess Margaret Cancer Centre / UHN, Hamilton General Hospital, The Ottawa Hospital, Vancouver General Hospital, Misericordia Edmonton, and Foothills Calgary are the leading centres. The Canada Hyperbarics verified directory at canadahyperbarics.ca/facilities/ lists all programmes with phone numbers, addresses, and current operational status.
Related conditions: Delayed Radiation Injury and HBOT