Radiation Therapy for Kaposi Sarcoma

Radiation therapy uses high-energy radiation to kill cancer cells. When the radiation is delivered from outside the body it is called external beam radiation therapy. This is the type of radiation therapy used to treat lesions of Kaposi sarcoma (KS).

Radiation therapy is often effective as a type of local therapy to treat KS lesions on or near the surface of the body. Radiation is used to reduce symptoms like pain or swelling. It is also used for skin lesions that look bad and are in places that can easily be seen (like the face).

For KS lesions on the skin, the form of radiation most often used is called electron-beam radiation therapy (EBRT). It uses tiny particles called electrons that don’t penetrate far past the skin’s surface. This limits non-skin side effects. EBRT can also be used to treat large areas of the skin if a person has many widespread KS lesions.

Radiation can also be used to treat KS lesions in the mouth or throat. The form of radiation used for this, known as photon radiation, can penetrate deeper into the body.

Radiation treatments for KS lesions are often given once a week for several weeks. Getting treatment is much like getting an x-ray, but the radiation is stronger. The procedure itself is painless. Each treatment lasts only a few minutes, although the setup time − getting you into place for treatment − takes longer.

Side effects of radiation therapy can include skin changes, nausea, vomiting, and fatigue, Radiation can also cause anemia (low red blood cells), as well as lower numbers of white blood cells, which increases the risk of infection.

Serious side effects are rare when radiation is given to just a small area of the skin, but a small portion of patients have severe skin reactions.

When radiation is used to treat KS lesions in the mouth or throat, these areas can become painful and open sores can develop. If chemotherapy and radiation are given at the same time, the side effects are worse.

For more general information on radiation therapy, see the Radiation Therapy section of our website or A Guide to Radiation Therapy.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: August 8, 2014 Last Revised: February 9, 2016

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