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Radiation Therapy for Acute Lymphocytic Leukemia (ALL)

(Note: This information is about treating acute lymphocytic leukemia (ALL) in adults. To learn about ALL in children, see Leukemia in Children.)

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. This planning session, called simulation, usually includes getting imaging tests such as CT or MRI scans.

Radiation treatment is much like getting an x-ray, but the radiation is much stronger. 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 number of treatments you get depends on the reason radiation therapy is being used. 

Side effects

The possible side effects of radiation therapy depend on 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 (if the head or belly is being treated)
  • Diarrhea (if the belly or pelvis is being treated)
  • Mouth sores and trouble swallowing (if the head and neck area are being treated)
  • Headaches (if the head is being treated)
  • Lowered blood cell counts, which can lead to fatigue and shortness of breath (from low red blood cell counts), bleeding or bruising (from low platelet counts), and an increased risk of infection (from low white blood cell counts)

More information about radiation therapy

To learn more about how radiation is used to treat cancer, see Radiation Therapy.

To learn about some of the side effects listed here and how to manage them, see Managing Cancer-related Side Effects.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Appelbaum FR. Chapter 98: Acute Leukemias in Adults. In: Niederhuber JE, Armitage JO, Dorshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, Pa. Elsevier: 2014.

Jain N, Gurbuxani S, Rhee C, Stock W. Chapter 65: Acute Lymphoblastic Leukemia in Adults. In: Hoffman R, Benz EJ, Silberstein LE, Heslop H, Weitz J, Anastasi J, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, Pa: Elsevier; 2013.

National Comprehensive Cancer Network. NCCN Practice Guidelines in Oncology: Acute Lymphoblastic Leukemia. V.1.2018. Accessed at on July 26, 2018.

Last Revised: October 17, 2018

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