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Radiation therapy uses high-energy rays (such as x-rays) or particles to kill cancer cells. External beam radiation therapy focuses radiation from outside the body on the skin tumor. This type of radiation therapy is used to treat some patients with melanoma.

Before 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. The 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 – usually takes longer.

When might radiation therapy be used?

Radiation therapy is not often used to treat the original melanoma that started on the skin, although it is sometimes used after surgery for a type of melanoma known as desmoplastic melanoma.

Sometimes, radiation is given after surgery in the area where lymph nodes were removed, especially if many of the nodes contained cancer cells. This is to try to lower the chance that the cancer will come back.

Radiation therapy can also be used to treat melanoma that has come back (recurred) after surgery, either in the skin or lymph nodes, or to help treat distant spread of the disease.

Radiation therapy is often used to relieve symptoms caused by the spread of the melanoma, especially to the brain or bones. Treatment with the goal of relieving symptoms is called palliative therapy. Palliative radiation therapy is not expected to cure the cancer, but it might help shrink it or slow its growth for a time to help control some of the symptoms.

Stereotactic radiosurgery (SRS)

SRS is a type of radiation therapy that can sometimes be used for tumors that have spread to the brain. (Despite the name, there is no actual surgery involved.) In one version of this treatment, a machine called a Gamma Knife® focuses about 200 beams of radiation on the tumor from different angles over a few minutes to hours. The head is kept in the same position by placing it in a rigid frame. In another version, a linear accelerator (a machine that creates radiation) that is controlled by a computer moves around the head to deliver radiation to the tumor from many different angles. These treatments can be repeated if needed.

Possible side effects of radiation therapy

Common side effects depend on where the radiation is aimed and can include:

  • Sunburn-like skin problems
  • Hair loss where the radiation enters the body
  • Fatigue
  • Nausea
  • Loss of appetite and weight loss

Often these go away after treatment. When radiation is given with chemotherapy, the side effects are often worse.

Radiation therapy to the brain can sometimes cause memory loss, headaches, trouble thinking, or reduced sexual desire. Usually these symptoms are minor compared with those caused by a tumor in the brain, but they can still affect your quality of life.

To learn more about radiation, see the Radiation Therapy section of our website.

Last Medical Review: 03/19/2015
Last Revised: 02/01/2016