Radiation therapy uses high doses of X-rays or other types of energy to kill cancer cells or stop them from growing.

While surgery is the main treatment for melanoma, radiation can sometimes be very useful. It may be used on its own or along with other types of treatment. Your doctor may suggest this treatment for many reasons:

• After surgery. Radiation can be used to kill any cancer cells that may remain near the surgical site or after lymph nodes were removed. This can help lower the chance that the cancer will come back.
• Surgery can't be done. Radiation might be the main treatment if, for example, you're not in good health or the melanoma is in a hard-to-treat area. This might include your eyelid, nose, or ear. Certain types of melanoma can be sensitive to radiation therapy.
• Melanoma comes back. Radiation can be used to treat cancer that grows again after surgery, either on your skin or in your lymph nodes.
• To control symptoms. Radiation therapy might help reduce pain or other symptoms caused by melanoma that has spread to your brain, spinal cord, or other organs.

To plan your treatment, you'll meet with a team of cancer specialists. This might include a surgeon, radiation oncologist, and medical oncologist.

A doctor who specializes in treating cancer with radiation is called a radiation oncologist. This doctor works with you to decide the kind of radiation you need. They also determine the dose and how long you'll need treatment.

The most common way to get radiation for melanoma is from a large machine that focuses beams of radiation at the cancer. This is called external beam radiation therapy (EBRT). Sometimes the external beam radiation can be delivered in a special technique, such as intensity-modulated radiation therapy (IMRT), to try to limit the amount of radiation that reaches and damages nearby normal cells.

External beam radiation is given on an outpatient basis in a hospital or clinic. This means you go home the same day. It's usually given 5 days a week, Monday through Friday, for several weeks. Treatment takes a few minutes with each session.

Before your first radiation treatment, you'll have a simulation (planning) appointment. This procedure is needed to find exactly where on your body the radiation beam will be directed. It may take up to 2 hours. During this session, imaging tests, like an MRI, CT scan, or PET scan will be done. The detailed images are used to clearly outline the size and shape of the tumor. The radiation beams are controlled and formed to fit this shape and focus on the tumor that is seen on the simulation scans. This helps limit damage to nearby healthy tissue.

Then, you'll lie still on a table while a radiation therapist uses a machine to define your treatment field. The field is the exact area on your body where the radiation will be aimed. Sometimes it's called your port. The therapist may mark your skin with tiny dots of semipermanent ink or tattoos. This is so the radiation will be aimed at the exact same place each time. At this session, you may have body molds made, too. These help put you in the exact same position. They also help keep you from moving during treatments.

On the days you get radiation treatment, you'll lie on a table. The machine rotates around you. You may have to wear a hospital gown. Each treatment is a lot like getting an X-ray, but it takes longer, up to 15 to 30 minutes. You should plan on being there for about an hour in total.

At the start of the treatment session, a radiation therapist helps you get into position. They may use blocks or special shields to protect parts of your body from unnecessary exposure to radiation. The therapist then lines up lights on the machine with the marks on your skin. This helps ensure the radiation is directed to the right spot. When you're ready, the therapist leaves the room and turns the machine on. You may hear whirring or clicking noises as the machine moves during radiation. This may sound like a vacuum cleaner. The machine won't touch you. During the session, you'll be able to talk with and hear the therapist over an intercom. You can't feel radiation, so the process will be painless. You won't be radioactive after the treatment.

Because radiation affects normal cells, as well as cancer cells, you may have some side effects. The side effects from radiation are normally limited to the area being treated. Some people have few or no side effects. If you do have them, your doctor may change the dose of your radiation or how often you get treatment. Or treatment may be stopped until your side effects get better. Tell your doctor right away about any side effects you have. It's important to treat them before they get worse.

The side effects of radiation depend on the amount and the type of radiation you get as well as the exact part of your body being treated.

Side effects can include:

• Skin problems, including redness, dryness, burning, blistering, or peeling in the area being treated.
• Severe tiredness (fatigue).
• Appetite loss.
• Nausea.
• Diarrhea, if your belly (abdomen) is being treated.
• Hair loss, if your head is being treated.
• Dry mouth and mouth and throat sores, if that area is being treated.
• Higher risk for infection.

Most of these side effects go away over time after your treatment is complete. Still, if you have any side effects, talk with your doctor about how to deal with them. You should also ask what side effects you might expect. Find out what to do if they become serious. Find out what the best way is to contact your doctor with questions or problems. What is the best contact number or contact method for evenings, holidays, and weekends?

Some long-term side effects of radiation may not show up for many years after you finish treatment. These depend on the dose of the radiation and the area that was treated. Side effects also depend on how many times you have treatment. Ask your doctor what you can expect.

It may be helpful 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'll also make it easier for you to work with your care team and make a plan to manage side effects.

Talk with your doctor about what side effects you can expect. Also talk about what can be done to prevent or ease them.

Ask your doctor what symptoms to watch for. Know when you should contact your care team and how to get help after office hours and on weekends and holidays. For instance, you might be asked to call your doctor if you have:

• Signs of infection, such as fever or chills.
• New symptoms.
• Symptoms that don't get better with treatment.
• Side effects that are causing a lot of discomfort or that affect your ability to do daily activities.