Total body irradiation is the medical use of radiation to destroy cancer cells throughout the body. Oncologists use the procedure for patients scheduled for bone marrow transplants—treatment doctors often recommend for certain cancers or diseases that affect the production of bone marrow cells.
If your doctor schedules you for total body irradiation, it's natural to have fears and anxieties relating to the process. Therefore, it's important to ask questions to get the full benefit that this or any medical treatment has to offer.
Why do doctors recommend total body irradiation prior to a bone marrow transplant?
Total body irradiation is a treatment that prepares the body to accept the donor stem cells. Chemotherapy—another cancer treatment that uses drugs—doesn't always reach cancer cells in the brain or spine. Oncologists also recommend total body irradiation to destroy cancer cells in the bones and deep scar tissue.
Another reason for the use of total body irradiation prior to a bone marrow transplant is to suppress the immune system response. This prevents your body from trying to destroy the healthy donor cells as foreign invaders. Total body irradiation also stops blood cell production in the marrow, making space for new blood cells following transplantation to reproduce and grow.
What factors does a treatment team take into account when planning total body irradiation?
Oncologists often use total body irradiation in combination with chemotherapy. The challenge is to use a dose of radiation low enough so that any healthy cells damaged during treatment can recover.
Since the lungs are highly sensitive to radiation, they will receive a lower dose of radiation than the rest of your body. The use of shields known as lung blocks also helps prevent lung damage.
However, the bones in the chest wall behind the blocks contain a significant amount of bone marrow. Therefore, you will receive radiation to the front and back of your chest wall without the blocks during some treatment sessions.
How does total body irradiation as part of the treatment protocol work?
Your oncologist will plan the dose of radiation that you will receive over a period of several days prior to your bone marrow transplant. The actual treatment schedule varies depending on the disease for which you are being treated as well as the type of bone marrow transplant you will receive.
You will be scheduled for multiple radiation therapy sessions each day of treatment. In some cases, certain areas of your body will receive extra doses of radiation before you receive total body irradiation.
Once the radiation therapists position you for total body irradiation, it's important not to move so that the radiation is evenly distributed over your body. During each treatment, you will receive radiation to the front of your body and then the back.
What are the potential side effects during and following total body irradiation?
Because radiation therapy damages healthy cells along with cancerous cells in the body, you may experience side effects. The treatment itself is painless, but the severity of any side effects you may experience can vary depending on the dose of radiation you receive.
Common side effects include fatigue, nausea and vomiting, diarrhea, and headache. Some side effects occur during the days when you are receiving treatments; others do not occur for weeks or even months after treatment. Additional side effects—which also may be side effects of chemotherapy you are receiving—include hair loss, low blood counts, and mouth sores.
Although rare, long-term side effects that can occur months or years later include cataracts and inflammation of the lungs or sac surrounding the heart. In some cases, new cancers may develop.
Why is it important to ask questions?
Knowing the details of why your doctor is recommending total body irradiation and how it will be done can help assure you that your health care team is committed to doing what is best for your particular situation. Asking questions also allows you to take a more active involvement in your treatment decisions. Click here for more information on radiation therapy in your area.