Radiation Therapy for Childhood Leukemia

Radiation therapy uses high-energy radiation to kill cancer cells.

Radiation is not always needed to treat leukemia, but it can be used in certain situations:

• It is sometimes used to try to prevent or treat the spread of leukemia to the brain or treat the testicles in boys if the leukemia has reached them. But chemotherapy is often used in these situations instead.
• It can be used (rarely) to treat a tumor that is pressing on the trachea (windpipe). But chemotherapy is often used instead, as it may work more quickly.
• Radiation to the whole body is often an important part of treatment before a stem cell transplant (see High-Dose Chemotherapy and Stem Cell Transplant).

How is radiation therapy given?

Before treatment starts, the radiation team will take careful body measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. This planning session, called simulation, usually includes getting imaging tests such as CT or MRI scans.

The treatment itself is much like getting an x-ray, but the radiation is much stronger. It is painless, but some younger children may need to be sedated to make sure they don’t move during the treatment. Each treatment lasts only a few minutes, although the setup time – getting your child into place for treatment – usually takes longer.

Possible side effects of radiation

The possible short-term side effects depend on where the radiation is aimed, and can include:

• Sunburn-like skin changes
• Hair loss in the treated area
• Nausea, vomiting, or diarrhea (from radiation to the abdomen) 
• Fatigue
• Increased risk of infection

Longer-term side effects are also possible and are described in Living as a Childhood Leukemia Survivor.