Radiation Tissue Damage

Radiation therapy for the treatment of solid tumors allows previously untreatable cancers to be cured.  The radiation used to fight cancer also damages normal tissue in the path of the beam.  Even today, many physicians consider chronic radiation damage to be irreversible, but HBOT offers help in repairing damage.

Each year, Americans have about 20 million radiation treatments, with each patient averaging about 24 treatments.  These treatments can produce side effects.  Radiation treatment works by damaging cancer cells, which reproduce more quickly than healthy cells and are more susceptible to radiation while they are reproducing.  No matter how carefully the tumor cells are targeted some of the normal cells are affected.  Radiation damage is called radionecrosis.

Damage usually appears during the subacute and chronic stages.  The subacute stage occurs in the second six months and as treatment goes on permanent tissue damage becomes apparent.  The chronic stage happens from the second to fifth years after radiation exposure.  Damage is evident, the capillaries deteriorate and this results in reduced blood and oxygen flow and the buildup of toxic cell wastes.  Tissue function is reduced and resistance to infection is lowered.

HBOT helps fight this damage by increasing the amount of oxygen within the tissue to aid in the recovery.  Extra oxygen stimulates the skin to form new collagen (the basic material for wound healing).  New collagen enhances the formation of new capillaries that can allow skin ulcers to heal and skin grafts to take.

Researchers and clinicians do not administer HBOT immediately after radiation because it may enhance the effects of radiation on sensitized tissue.  HBOT is started about two months or more after the patient’s last radiation treatment.

In an important study done in the 1980s by Dr. George Hart and Dr. M.B. Strauss cited by Neubauer, 336 patients were treated with HBOT as an adjunct to surgery and other treatments.  HBOT was given at 2.0 ATA for two hours once a day for outpatients, or 1.5 ATA twice a day for inpatients, for a total of 120 hours maximum.   If the healing was not adequate, the treatment was repeated after a three- to six-month rest period.  The findings showed that HBOT caused a significant reduction in the disease effects when compared with what could normally be expected.

Radiation damages different tissues in different ways.  There is soft-tissue damage and bone damage. Soft-tissue damage includes nervous system damage, head and neck damage and genitourinary tract damage. These complications result when radiation damages capillaries in the spinal cord and brain.  Blood clots form causing a reduction in blood flow and hypoxia, radiation myelitis and radiation encephalopathy.  Myelitis is an inflammatory disease that affects the spinal cord.  Inflammation results in a loss of the cord’s ability to transmit nerve impulses and the symptoms can mimic those of a severed cord. Encephalopathy is a condition that affects brain functioning.

Patients received HBOT at 2 ATA for 90 minutes per session, twice a day for two weeks.  Researchers concluded that HBOT is beneficial in treating these conditions.  They suggest that at least eight months should pass following the last radiation treatment.54

HBOT helped patients with redionecrosis of the larynx (voice box). Symptoms of pain, difficulty in swallowing and obstruction of breathing were reduced and laryngectomies were reduced.  In the genitourinary tract, symptoms of blood in the urine, cystitis (inflammation of the bladder) and secondary infection is usually present.  Drug treatment has not been effective.  Treatment was given at 3 ATA for 90 minutes a day, five treatments a week, for an average of four weeks.55 Symptoms improved and patients’ bladders showed significant reversal of tissue injury.

Another study, by Dr. J.B. Weiss and Dr. E.C. Neville, used a protocol of two hours of HBOT at 2 ATA.  Improvements took place in an average of two years.

Miscellaneous soft-tissue damage affects various locations all over the body.  Radiation hitting blood vessels can bring about swelling, degeneration, and death of the vessel walls. Capillaries and the smallest arteries are damaged the most.  In the chronic stage of radiation damage the skin dies, and ulcers develop after minor injuries.  Evidence is good for healing radiation skin damage when skin grafts were used following injury, and injuries healed in a majority of cases.

Soft tissue damage protocols are generally 2.4 ATA in 90-minute sessions.  Between 20 and 30 sessions are usually given depending on patient response.

Notes
54Neubauer, 97.
55Ibid., 98.