Delayed Radiation Injury Following Cancer Therapy
One half of the estimated 1.2 million new cases of
invasive cancer will receive radiation therapy as a part of cancer treatment for
malignant tumors. Radiation therapy can sometimes cause additional painful
or troublesome complications called "side effects." The therapy can be very
toxic, especially when combined with chemotherapy and some people are more
sensitive to radiation damage than others. Unfortunately, there are no reliable
tests available yet to identify those patients who will experience the worst
Some side effects are acute and occur during or shortly after radiation treatments and improve with time. Others are long term and may not show up for years after the radiation treatments. Long term "chronic" radiation injury is called "osteoradionecrosis" if the bone has been damaged and "soft tissue radionecrosis" if the muscle, skin or internal organs has been damaged by the radiation. While acute side effects improve over time, chronic side effects often do not get better with time and are likely to get worse.
A common symptom of radiation injury is pain in the effected area. Head, neck and jaw symptoms may include additional difficulties with eating. Symptoms of pelvic radiation injury may include bleeding from the bowel or while urinating, urgency, incontinence or diarrhea. Please see the link Radiation Tissue Injury for more information about symptoms.
Managing chronic side effects
Radiation doses must be adequate to control the cancer; otherwise there is no purpose in treating the patient. While radiation cancer specialists design their treatments to irradiate cancer cells, some irradiation of healthy cells is unavoidable. As a result, 1 to 5 percent of radiation therapy patients develop chronic reactions to treatment.
In the past, a severe level of radionecrosis would require surgical removal of the damaged tissue. This could be devastating for a patient whose cancer has been cured but, for example, had to undergo removal of the voice box due to radiation injury. Today, hyperbaric oxygen offers relief and significant improvement in the majority of those patients treated. See What is Hyperbaric Oxygen Therapy for more information.