Radiation Therapy for Acute Lymphocytic Leukemia

Radiation therapy uses high-energy radiation to kill cancer cells. It is not usually part of the main treatment for people with acute lymphocytic leukemia (ALL), but it is used in certain situations:

• Radiation is sometimes used to treat leukemia that has spread to the brain and spinal fluid or to the testicles.
• Radiation to the whole body is often an important part of treatment before a bone marrow or peripheral blood stem cell transplant (see “ High-dose chemotherapy and stem cell transplant for acute lymphocytic leukemia”).
• Radiation is used (rarely) to help shrink a tumor if it is pressing on the trachea (windpipe) and causing breathing problems. But chemotherapy is often used instead, as it may work more quickly.
• Radiation can also be used to reduce pain in an area of bone invaded by leukemia, if chemotherapy hasn’t helped.

External beam radiation therapy, in which a machine delivers a beam of radiation to a specific part of the body, is the type of radiation used most often for ALL. Before your treatment starts, the radiation team will take careful measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. Radiation therapy is much like getting an x-ray, but the radiation is more intense. The procedure itself is painless. Each treatment lasts only a few minutes, although the setup time – getting you into place for treatment – usually takes longer.

The possible side effects of radiation therapy depend on the dose given and where the radiation is aimed. They include:

• Fatigue (tiredness)
• Skin changes in the treated area, which can range from mild redness to burning and peeling
• Hair loss in the area being treated
• Nausea and vomiting (more common if the abdomen/belly is being treated)
• Diarrhea (more common if the belly or pelvis is being treated)
• Lowered blood cell counts, which can lead to fatigue and shortness of breath (from low red blood cell counts) and an increased risk of infection (from low white blood cell counts)