Radiation Therapy for Chronic Myelomonocytic Leukemia (CMML)

Radiation therapy is treatment with high-energy rays or particles to kill cancer cells. It is not a common treatment for chronic myelomonocytic leukemia (CMML), but it might be used in some situations.

How are radiation treatments given for CMML?

The most common form of radiation therapy is external beam radiation therapy. For this treatment, 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 proper dose of radiation and the correct angles for aiming the radiation beams.

Each treatment lasts only a few minutes, but the setup time (getting you into place for treatment) usually takes longer. External beam radiation therapy is a lot like getting an x-ray, but the radiation is much stronger. The treatment itself is painless.

When is radiation therapy used for CMML?

Radiation therapy is not a common treatment for chronic myelomonocytic leukemia (CMML) because the leukemia cells are throughout the body. But there are a few situations where it might be used.

To shrink an enlarged spleen

If someone with CMML is having problems from a very enlarged spleen, radiation therapy may be used to shrink it.

Shrinking your 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 your spleen helps protect against infections, this can increase your risk of severe infections.

If you are considering treatment with radiation for an enlarged spleen, talk with your health care team about the risks and benefits. You may also need to get certain vaccines before radiation starts.

Before a stem cell transplant

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 this radiation is to kill the cells in your bone marrow, including the leukemia cells. These cells are then replaced with normal cells when you get the stem cell transplant.

Side effects of radiation treatment

Possible side effects of radiation therapy include:

• Sunburn-like changes and hair loss in areas of skin the radiation passes through
• Nausea, vomiting, or diarrhea from radiation aimed at the abdomen (belly)

Possible side effects of total body irradiation (TBI) also include:

• Fatigue (from low red blood cell counts)
• Bleeding or bruising (from low platelet counts)
• Increased risk of infection (from low white blood cell counts)