Jan 23, 2005 - 7:43 pm
HBO Therapy For Radiation-induced Necrosis
Radiation-induced necrosis has been estimated to occur in 20% to 25% of patients for cancerous tumors in the brain. Some studies say it can develop in at least 40% of patients irradiated for tumors following large volume or whole brain radiation and possibly 3% to 9% of patients irradiated focally (as in stereotactic radiation) for brain tumors (in reality, they just don't know). Even with more localized use of radiation, significant neurological deficits can result.
The diagnosis of radiation-induced necrosis is difficult to confirm. Many patients have a mixture of tumor and radiation necrosis and a biopsy may be necessary to distinguish it. Neither symptoms nor radiographic findings clearly distinguish radiation-induced necrosis from tumor. However, the FDG-PET Scan and T1-SPECT studies are useful in differentiating radiation-induced necrosis from recurrent tumor.
PET is useful in a variety of therapy-monitoring applications, including distinguishing between radiation necrosis and recurrence; determining the resectability of a recurrence; and evaluating response to chemotherapy or radiation therapy. This is because effective therapy leads to rapid reductions in the glucose uptake levels of tumors. PET tracers can easily reveal this drop in metabolic activity and show - sometimes within minutes or hours - whether a patient is responding positively to a particular course of treatment. With this information, physicians can quickly modify less effective therapy, thereby improving patient outcomes and reducing the cost of ineffective treatment.
Radiation-induced necrosis is a serious reaction to radiation treatment. It may result from the death of tumor cells and associated reaction in surrounding normal brain or it may result from the necrosis of normal brain tissue surrounding the previously treated metastatic brain tumor. Such reactions tend to occur more frequently in larger lesions, either primary brain tumors or metastatic tumors.
Hyperbaric Oxygen Therapy (HBOT) is now a useful terapeutic option for patients with confirmed symptomatic radiation necrosis. I've received a number of emails from radiation necrosis patients who had HBO Therapy, and (the good news is) it works!
The most common condition treated at some Hyperbaric Oxygen Therapy Centers is tissue injury caused by brain radiation therapy for cancer. Wound healing requires oxygen delivery to the injured tissues. Radiation damaged tissue has lost blood supply and is oxygen deprived. Chronic radiation complications result from scarring and narrowing of the blood vessels within the area which has received the treatment. Hyperbaric Oxygen Therapy provides a better healing environment and leads to the growth of new blood vessels in a process called re-vascularization. It also fights infection by direct bacteriocidal effects. Using hyperbaric treatment protocols, "most" patients with chronic radiation injuries can be cured.
Hyperbaric oxygen therapy is administered by delivering 100 percent oxygen at pressures greater than atmospheric (sea level) pressure to a patient in an enclosed chamber. Hyperbaric oxygen acts as a drug, eliciting varying levels of response at different treatment depths, durations and dosages, and has been proven effective as adjunctive therapy for specifically indicated conditions.
Oxygen is a natural gas that is absolutely necessary for life and healing. Purified oxygen is defined as a drug but is the most natural of all drugs. Oxygen under pressure is still the same gas but is more able to penetrate into parts of the body where the arterial flow is hindered, producing ischemia (loss of blood flow) and hypoxia (lack of oxygen). When oxygen under pressure is breathed by a patient in a sealed chamber, it is termed a hyperbaric oxygen treatment (HBOT).
In addition to raising the arterial levels of oxygen 10 to 15 times higher than that produced by normal atmospheric pressure, the pressure exerted within the body can and does exert therapeutic benefits on acute and chronically traumatized and swollen tissus.
If on medicare, the approved course is 2.0 atm (two times above atmospheric pressure) for 90 minutes 20-30 sessions. For hyperbaric oxygen therapy to be covered under the Medicare program in the United States, the physician must be in constant attendance during the entire treatment. This is a professional activity that cannot be delegated in that it requires independent medical judgment by the physician. The physician must be present, carefully monitoring the patient during the hyperbaric oxygen therapy session and be immediately available should a complication occur. This requirement applies in all settings and no payment will be made by Medicare unless the physician is in constant attendance during the procedure.