Physician Referral Guide: Hyperbaric Oxygen for Radiation Damage Affecting Bone (Osteoradionecrosis)

Assessing the patient before referral

Because this is elective adjunctive care, the referring clinician or dental or maxillofacial team should arrange the following before or alongside hyperbaric assessment:

• Confirm the diagnosis and exclude recurrence. Imaging and, where indicated, biopsy should establish ORN and rule out recurrent or persistent tumour in the field, since active malignancy in the treatment area is a relative contraindication.
• Document the radiation history: site, total dose where available, and time since radiotherapy, as ORN risk rises with higher cumulative mandibular dose.
• Review the cancer-treatment medication history, in particular any current or prior bleomycin exposure, which affects pulmonary safety in the chamber and may require pulmonary-function review, and any concurrent disulfiram.
• Screen for chamber fitness: untreated pneumothorax, severe chronic obstructive pulmonary disease with bullous lung disease, uncontrolled seizure disorder, recent middle-ear or sinus surgery, claustrophobia, and cardiac status, so the programme can assess suitability.
• Coordinate timing with the planned procedure, since the regimen delivers a defined number of sessions before surgery and a further course afterward.

What the evidence supports

The foundational work is the Marx histology and clinical series (J Oral Maxillofac Surg, 1983), which described irradiated bone as characterised by tissue that is hypoxic, hypovascular, and hypocellular, and reported that staged HBOT before and after surgical intervention improved healing of irradiated jaws. This work defined the still-used prophylactic regimen.

The mechanistic rationale is well described. Radiotherapy causes progressive endothelial damage and obliteration of small vessels, leaving bone chronically hypoxic and less able to heal or to mount a normal response to injury. HBOT raises tissue oxygen tension enough to stimulate angiogenesis, an effect attributed to sustained oxygen gradients and elevation of pro-angiogenic signals including vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1), with recruitment of bone-marrow-derived endothelial progenitor cells. Over a course of treatment, Marx's histology described capillary density in irradiated tissue increasing substantially toward normal, with new vessels still present on biopsy years later. HBOT also supports collagen synthesis and oxygen-dependent neutrophil function. On this model the angiogenic effect is intended to be durable rather than a temporary rise in oxygen during a single session, though the supporting human data are largely observational.

The trial evidence is mixed and should be presented honestly. A Cochrane systematic review (Bennett et al. 2016, updated as Lin and Bennett 2023) pooling randomised trials concluded that HBOT may improve some outcomes in established osteoradionecrosis, including reduced wound dehiscence after head and neck soft-tissue surgery and modest pain improvement, but that the certainty of the evidence is low and trial quality is variable. Two randomised controlled trials specifically questioned prophylactic and established-ORN benefit: DAHANCA-21 (combined with NWHHT2009-1) did not show a statistically significant advantage of HBOT for surgically managed established mandibular ORN, and the HOPON trial did not demonstrate a significant reduction in ORN when HBOT was added before dental extraction or implant surgery in irradiated patients. HBOT is therefore best framed as an adjunct to surgical and dental management of irradiated bone, not as a standalone cure, with the strongest support in established ORN and the prophylactic benefit uncertain.

The Canadian referral pathway

Osteoradionecrosis is an accepted elective indication at Canadian hospital-based hyperbaric programmes and is covered by provincial health insurance. Referral is usually made by the treating dental, maxillofacial, or oncology service in coordination with the regional hyperbaric unit. Because care is elective, the route is a standard specialist referral to the nearest programme rather than an emergency transfer line.

• Ontario (OHIP): Toronto General Hospital (UHN), Hamilton General Hospital, and The Ottawa Hospital programmes accept elective referrals for irradiated-bone HBOT.
• British Columbia (MSP): Vancouver General Hospital, the hospital chamber for the province.
• Alberta (AHCIP): Misericordia Community Hospital (Edmonton) or Foothills Medical Centre and the Arthur J.E. Child Comprehensive Cancer Centre (Calgary).
• Quebec (RAMQ): Hopital du Sacre-Coeur de Montreal and Hotel-Dieu de Levis.
• Atlantic Canada: hospital hyperbaric programmes are available in Nova Scotia (MSI) and Newfoundland and Labrador (MCP).
• Provinces and territories with limited or no in-province elective capacity (Manitoba, New Brunswick, PEI, Yukon, NWT, Nunavut, and Saskatchewan, where the sole chamber closed in 2021 and has since operated only on a reduced schedule): patients are often referred inter-provincially to the nearest accepting programme, most often Edmonton or the Ontario programmes. For elective courses, travel and accommodation are usually the patient's responsibility unless medical-travel assistance applies.

How to use the research list below

The list contains every osteoradionecrosis and radiation-bone-injury study in the Canada Hyperbarics database that was published in 2020 or later and has a freely available full-text version, each linked directly to that full text. Paywalled and abstract-only studies are excluded, and retracted studies are removed. This is a reference list, not a set of summaries. Counts and the open-access set refresh each quarter.