Delayed Radiation Tissue Injuries
Hyox’s clinical outcomes are extremely successful in patients with delayed radiation tissue injuries; most noteably in head and neck cancer. Hyperbaric oxygen therapy works to grow new blood vessels (angiogenesis) and fibroblasts (cells that promote healing by producing collagen) to bring about radiated tissue wound healing.
Various conditions and complications may result from radiation therapy in some patients affecting normal, non-cancerous cells. This includes blood vessel, muscle, and nerve cells. As radiation therapy is working to eradicate cancer, much of the oxygen content in the radiated tissue is lost and, in some instances, damage is caused in the surrounding area. The damage may result in compromised tissue, wounds and other complications needing the beneift of hyperbaric oxygen therapy.
In a prospective assessment of outcomes in 411 patients treated with hyperbaric oxygen for chronic radiation tissue injury, outcomes strongly supported the efficacy of hyperbaric oxygen treatment for the radiation conditions evaluated.
Soft Tissue and Bony Necrosis
While radiation therapy kills cancerous cells, sometimes normal cells are affected. Over time, the cells in the radiated tissue lose much of their oxygen content causing scarring, increased risk of infection, ulceration, bone necrosis, and poor wound healing of accidental or surgical wounds from breast reconstruction or dental work. Abnormal radiated tissue can cause other health conditions like fistulas (abnormal tracts or openings) in the body. Common conditions include radiation induced cystitis (inflamed bladder) and proctitis (inflammation of the rectum lining).
Referral Protocol: Immediately, when edema, bleeding and pain persist and affect quality of life as a result of radiation cystitis or proctitis. In a case series reported by Corman and updated by Chong early intervention has increase the rate of improvement from 80 percent to 96 percent when hyperbaric oxygen therapy begins within six months of onset of hematuria. Decrease clot retention was seen in 100 percent of patients treated within six months.
A side effect from cancer treatment is bone cell damage, called osteoradionecrosis (ORN). ORN also affects the blood cells supplying the bone. The areas of the body most commonly damaged are the lower jaw (mandible), the chest wall, pelvis, vertebral column, and skull. Wounds to the damaged bone fail to heal because of hypoxia or an inadequate supply of oxygen.
Hyperbaric oxygen therapy works to reverse the damage to the bone through tissue oxygenation. Treatment and prevention of radiation necrosis of the mandible as a result of avascular, aseptic necrosis is the most widely applied and extensively documented indication for hyperbaric oxygen in chronic radiation injury. ORN is also treated with debridement or surgical intervention depending on the severity and stage following the Marx Protocol.
Referral Protocol: Optimal clinical outcomes are achieved with appropriate surgical intervention to successfully eradicate all necrotic bone.
Patients who undergo radiation therapy sometimes experience complications long after the treatment. Soft tissue radionecrosis, especially of the head and neck, was studied by R.E. Marx, DDS. Dr. Marx found hyperbaric oxygen therapy to be useful “prior to surgery to create well-vascularized tissue that would subsequently heal and accept bone grafts.” The research, conducted at Wilford Hall Medical Center of the U.S. Air Force in San Antonio, Texas, has set the treatment protocols for HyOx.
Hyperbaric oxygen therapy delivered at HyOx works to heal the soft tissue by promoting angiogenesis, the growth of blood vessels into a tissue involving the development of new capillary blood vessels, in the injured areas. This allows for improved oxygenation and nutrition.
Head and Neck Cancers (prophylactic pre- and post-treatment for patients undergoing dental surgery of a radiated jaw)
Hyperbaric oxygen therapy is growing in its usage in treating radiation injury. It’s delivered using the Marx Protocol prior to dental extractions from heavily irradiated mandibles (jaws) and additional treatments are administered post-surgery to help support tissue metabolic demands in the healing process. The most common post-surgical hyperbaric oxygen therapy treatment is for maxillofacial osteoradionecrosis and osteomyelitis, which results in damage to the jawbone and tissues due to radiotherapy for cancer in the head and neck. The treatment also has shown to support dental implants in radiated tissues.
Hyperbaric oxygen therapy delivered at HyOx works to prevent radiation injury when the likelihood of complications from surgery is very high. Hyperbaric oxygen therapy provides a better healing environment and can also lead to growth of many new blood vessels (revascularization) around injured tissue, which can affect limb extremities.
Benefits of Adjunctive Hyperbaric Oxygen Therapy:
- Stimulates angiogenesis and secondarily improves tissue oxygenation – important and effective mechanisms by which hyperbaric oxygen therapy is effective in radiation injury since a consistent cause and manifestation of radiation injury is vascular obliteration and stromal fibrosis
- Reduces fibrosis
- Mobilizes and induces an increase of stem cells within irradiated tissues (1)
- Speeds the recovery of soft tissues and bone affected by radiation therapy’s fibro-atrophic effect (2) manifested by vascular changes characterized by obliterative endarteritis
- Enhances angiogenesis in hypoxic tissues (3) and bone as ORN is a result of an avascular, aspetic necrosis.
- Restores immune mechanisms that have become dysfunctional due to hypoxia which affects neutrophilic killings of organisms as phagocytosis becomes inefficient
- Re-establishes mandibular continuity in dentures and also helps rehabilitation for cosmesis and mastication (4)
- Supports initial tissue metabolic demands post-reconstructive surgery for ORN
- Assists certain antibiotics to work more effectively in soft tissue and bone infections by augmenting their transport across bacterial cell walls – this function is oxygen dependent and in a hypoxic environment impaired or disabled (tissue oxygen tension below 20-30 mmHg) (5)
- Resolves hematuria in radiation cystitis patients (6)
- Boosts the viability and vascularity of previously irradiated breast tissue prior to and post reconstructive surgery
- Stimulates angiogenesis / neovascularization in hypoxic tissues following the Marx Protocol for ORN (30 treatments pre- and 10 post-extraction) to achieve uncomplicated healing and viable tissue prior to surgery. (7, 8) *May require more treatments for mandibular resection and reconstruction success.
(1) Goldstein LJ, Gallaher KA, Bauer SM et al. Endothelial progenitor cell release into circulation is triggered by hyperoxia-induced increases in bone marrow nitric oxide. Stem Cells. 2006; 24:2309-2318.
(2) Delanian S, Lefaix J. Current management for late normal tissue injury: radiation-induced fibrosis and necrosis. Semin Radiat Oncol 2007; 17:99-107.
(3) Marx RE, Ehler WJ, Tayapongsak P, Pierce LW. Relationship of oxygen dose to angiogenesis induction in irradiated tissue. Am J Surg 1990; 160: 519-524.
(4) Marx RE. Radiation injury to tissue. In: Kindwall EP, ed. Hyperbaric Medicine Practice, Second Edition. Flagstaff, Best Publishing, 1999, pp. 665.723.
(5) Mader JT, et al. Hyperbaric oxygen as adjunctive therapy for osteomyelitis. Infect Dis Clin North Am, 1990. 4(3): 433-40.
(6) Corman JM, McClure D., Pritchett R, Kozlowski P, Hampson NB. Treatment of radiation induced hemorrhagic cystitis with hyperbaric oxygen. J Urol 2003; 160: 2200-2.
(7) Marx, RE, Ames JR. The use of hyperbaric oxygen in bony reconstruction of the irradiated and tissue deficient patient. J Oral Maxillofac Surg 1982; 40:412-9.
(8) Chavez JA, Adkinson CD. Adjunctive hyperbaric oxygen in irradiated patients requiring dental extractions: outcomes and complications. J Oral Maxillofac Surg 2001; 59:518-22.