What is radiotherapy?

Radiotherapy uses high-energy rays, such as x-rays, to treat cancer. It destroys cancer cells in the area where it is given.

We have more information about radiotherapy in general.

How radiotherapy is given

You have the treatment in the hospital radiotherapy department as a series of short, daily sessions. This is usually every day from Monday to Friday, with a rest at the weekend. Each treatment takes 10 to 15 minutes. Your doctor will talk to you about your treatment plan and the possible side effects.

Radiotherapy for recurrent melanoma

Doctors sometimes use radiotherapy to treat recurrent melanomas that cannot be removed with surgery or are not suitable for other treatments. It may help shrink large recurrences that are causing discomfort or pain. Your specialist will tell you if radiotherapy is suitable for you.

Radiotherapy for advanced melanoma

For advanced melanoma, radiotherapy may be given to help reduce pain and improve other symptoms. This is called palliative radiotherapy, because it is given to ease symptoms.

Radiotherapy can help improve symptoms when melanoma has spread to different parts of the body:

  • The skin or lymph nodes further away from the original melanoma – radiotherapy is sometimes used to help reduce the size of lymph nodes or skin nodules and improve symptoms, such as pain.
  • The bones – radiotherapy can help reduce bone pain and swelling.
  • The brain – radiotherapy can help shrink a secondary cancer in the brain and improve symptoms. Your doctors might suggest a newer radiotherapy technique called stereotactic radiosurgery (SRS).

You may need only a few sessions, or a short course of treatment. Your doctor will talk to you about your treatment plan and the possible side effects.

Radiotherapy for melanoma does not make you radioactive. It is safe for you to be with other people after your treatment, including children.

Planning your radiotherapy

You will have a hospital appointment to plan your treatment. You will usually have a CT scan of the area to be treated. During the scan, you need to lie in the position that you will be in for your radiotherapy treatment.

Your radiotherapy team use information from this scan to plan:

  • the dose of radiotherapy
  • the area to be treated.

You may have some small, permanent markings made on your skin. The marks are about the size of a pinpoint. They help the radiographer make sure you are in the correct position for each session of radiotherapy.

These marks will only be made with your permission. If you are worried about them, talk to your radiographer.

Treatment sessions

At the beginning of each session of radiotherapy, the radiographer will position you carefully on the couch and make sure you are comfortable. During your treatment you will be alone in the room, but you can talk to the radiographer who will watch you from the next room.

Radiotherapy is not painful, but you will have to lie still for a few minutes during the treatment.

Radiotherapy for melanoma does not make you radioactive. It is safe for you to be with other people after your treatment, including children.

Side effects of radiotherapy

Your team plans your treatment carefully to reduce your risk of side effects. However, most people have a few side effects during or after radiotherapy.

Recurrent melanoma

Radiotherapy can cause side effects in the area of the body being treated. You may also have some general side effects, such as feeling tired.

After treatment finishes, it may be 1 to 2 weeks before side effects start getting better. After this, most side effects usually slowly go away.

Your cancer doctor, specialist nurse or radiographer will tell you what to expect. They will give you advice on what you can do to manage side effects. If you have any new side effects or if side effects get worse, tell them straight away. They can give you medicines or advice to help.

Advanced melanoma

Radiotherapy will make you feel tired. This can last for some weeks after your treatment finishes.

Other side effects depend on the part of your body being treated and how much radiotherapy you are having. Usually when you are having radiotherapy to improve symptoms, the side effects are milder. This is especially true if you only have 1 or 2 treatments.

We have more information about radiotherapy for secondary bone cancer.

How we can help

Macmillan Cancer Support Line
The Macmillan Support Line offers confidential support to people living with cancer and their loved ones. If you need to talk, we'll listen.
0808 808 00 00
7 days a week, 8am - 8pm
Email us
Get in touch via this form
Chat online
7 days a week, 8am - 8pm
Online Community
An anonymous network of people affected by cancer which is free to join. Share experiences, ask questions and talk to people who understand.
Help in your area
What's going on near you? Find out about support groups, where to get information and how to get involved with Macmillan where you live.