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Chronic Myelomonocytic Leukemia (CMML)
Radiation therapy is treatment with high-energy rays or particles to kill cancer cells.
The most common form of radiation therapy is external beam radiation therapy, in which x-rays are aimed at the cancer from a machine outside the body.
Before your treatments start, the radiation team will take careful measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation.
Each treatment lasts only a few minutes, but the setup time -- getting you into place for treatment -- usually takes longer. Treatment is much like getting an x-ray, but the radiation is much stronger. The procedure itself is painless.
Radiation therapy is not a common treatment for chronic myelomonocytic leukemia (CMML), because the leukemia cells are throughout the body.
If someone who has CMML is having problems from a very enlarged spleen, radiation therapy may be used to shrink it. Shrinking the spleen can improve symptoms like belly pain and trouble eating, but there are some risks. Treating the spleen with radiation can affect how well it works. Since the spleen helps protect against infections, this can increase the risk of severe infections. If you are considering treatment with radiation for an enlarged spleen, talk about the risks and benefits with your doctor. You may also need to get certain vaccines before radiation starts.
Radiation therapy, in the form of total body irradiation (TBI), might be part of the treatment given before a stem cell transplant. The goal of radiation in this setting is to kill the cells in the bone marrow, including the leukemia cells, which are then replaced with normal cells when the person gets the transplant.
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.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines): Myelodysplastic Syndromes. Version 1.2024. Accessed at https://www.nccn.org on May 18, 2024.
Negrin RS. Preparative regimens for hematopoietic cell transplantation. UpToDate. 2024. Accessed at https://www.uptodate.com/contents/preparative-regimens-for-hematopoietic-cell-transplantation on May 19, 2024.
Padron E. Chronic myelomonocytic leukemia: Management and prognosis. UpToDate. 2024. Accessed at https://www.uptodate.com/contents/chronic-myelomonocytic-leukemia-management-and-prognosis on May 18, 2024.
Last Revised: May 21, 2024
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