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Radiation Therapy for Chronic Lymphocytic Leukemia

Radiation therapy is treatment with high-energy rays or particles to destroy cancer cells. Radiation therapy is seldom part of the main treatment for people with chronic lymphocytic leukemia (CLL), but it may be used in certain situations.

  • Radiation therapy can be used to treat symptoms caused by swollen internal organs (like an enlarged spleen) pressing on other organs. For instance, pressure against the stomach may make it hard to eat. If these symptoms are not improved by chemotherapy, radiation therapy may help shrink the organ.
  • Radiation therapy can also be useful in treating pain from bone damage caused by leukemia cells growing in the bone marrow.
  • Radiation therapy is sometimes given in low doses to the whole body, just before a stem cell transplant.

External beam radiation therapy, in which a machine sends a beam of radiation to a specific part of the body, is the type of radiation used most often for CLL. 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 a lot like getting an x-ray, but the radiation is more intense. The procedure itself is painless. Each treatment lasts only a few minutes, but the setup time − getting you into place for treatment − usually takes longer.

Common short-term side effects of radiation therapy include:

  • Skin changes in the treated area, which can vary from mild redness to what looks and feels like a burn
  • Fatigue
  • Low blood cell counts, increasing the risk of infection
  • Nausea and vomiting (which is more common with radiation to the belly)
  • Diarrhea (which is more common with radiation to the belly)

Ask your doctor what side effects you can expect.

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.

American Society of Clinical Oncology. Leukemia - Chronic Lymphocytic - CLL: Treatment Options. 06/2016. Accessed at on April 17, 2018.


National Comprehensive Cancer Network, Clinical Practice Guidelines in Oncology (NCCN Guidelines®), Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma, Version 5.2018 -- March 26, 2018. Accessed at on April 17, 2018.

Last Revised: May 10, 2018

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