Kaposi Sarcoma: Radiation Therapy

Radiation therapy uses high-energy beams of X-rays or particles to kill cancer cells or stop them from growing.

Radiation therapy can be used to treat Kaposi sarcoma (KS) lesions near the surface of the body, like on the skin or in the mouth. This is a type of local therapy. That means it treats only the cancer that it's aimed at. It doesn't treat the whole body.

Radiation therapy is most often used to treat lesions on the face. It can also be used to treat lesions that are causing symptoms (like pain or swelling) but are too big to be treated with other types of local therapy.

You'll meet with a team of cancer specialists to plan your radiation treatments. This team will include a radiation oncologist who specializes in radiation therapy and other types of health care professionals, such as radiation therapists and radiation nurses.

The most common way to get radiation therapy for KS is from a large machine that focuses beams of radiation on the cancer. This is called external beam radiation therapy. The two main types of external radiation that can be used to treat KS lesions are:

• Electron-beam radiation therapy. This type is mostly used for lesions on the skin. It doesn't go deep into the skin and the tissues below it. This limits the side effects it causes.
• Photon-beam radiation therapy. This type tends to be used for lesions in the mouth or throat. It can penetrate deeper into the body.

Your radiation oncologist will work with you to figure out the kind of radiation you need. This doctor also finds out the dose number of treatments you need and how long you need them. The radiation plan depends on the treatment goal, where the KS lesions are located, and how many will be treated.

You get radiation therapy as an outpatient in a hospital or a clinic. Outpatient means you go to get treatment each day but go home afterward. The typical treatment for KS is to get radiation daily for several weeks.

Before your first treatment, you might have a session to find out exactly where on your body the radiation beam needs to be directed. The process is called simulation.

On the days you get radiation treatment, you'll lie on a table while the machine moves over and around you. It doesn't touch you. You may have to wear a hospital gown. The experience is a lot like getting an X-ray, only longer. It takes about 15 to 30 minutes to complete. But you should plan on being there for about an hour.

At the start of the treatment session, a radiation therapist may place blocks or special shields to protect parts of your body that don't need to be exposed to radiation. The therapist then lines up the machine so that radiation is directed at the right spot. When you're ready, the therapist leaves the room and starts the machine. You may hear whirring or clicking noises, like the sounds of a vacuum cleaner, while the radiation is given. During the session, you'll be able to talk to and be heard by the therapist through an intercom. You can't feel radiation, and treatment doesn't hurt. You won't be radioactive afterward.

Radiation affects normal cells as well as cancer cells. Because of this, you may have some side effects from this treatment. But these are usually limited to the area being treated. Ask your doctor what short-term or long-term side effects you may have. Some people have few or no side effects. Treatment isn't usually changed for minor side effects. But if you do have severe side effects, your doctor may change the dose of your radiation or the frequency of treatments. Or the doctor may stop treatment until the side effects are gone. In either case, be sure you tell your doctor about any side effects you have. It's important to deal with them right away so they don't get worse.

Side effects might include:

• Skin irritation or changes in areas that get radiation.
• Nausea.
• Fatigue.
• Low blood counts.

Sometimes, treated KS lesions can become open sores, which might be painful. This is especially true for sores in the mouth or throat.

Usually side effects go away over time after you stop getting treatment.

If you have any side effects, talk with your health care team about how to deal with them and how to know when they become serious. Make sure you know what number to call with problems or questions. Find out the number for after office hours, on weekends, and holidays.

It may help to keep a diary of your side effects. A written list will make it easier to remember your questions when you go to appointments. It will also make it easier for you to work with your health care team to make a plan to manage side effects.