Planning external radiotherapy

Radiotherapy tattoos

You have small tattoos or skin markings as part of the radiotherapy planning. These help make sure that the external radiotherapy treatment is accurate.

Tattoo marks

During your radiotherapy planning session, your radiographer might make between 1 to 5 permanent pin point tattoo marks on your skin. For some types of radiotherapy, you might not have tattoo marks.

Your radiographer uses the tattoos to line up the radiotherapy machine for each treatment. This makes sure that they treat exactly the same area each time.

Photograph of radiotherapy tattoo marks.

Ink markings

Your radiographer might also draw marks around the tattoos with permanent ink pen. The room where you have treatment is dark, so this helps highlight the tattoos. This way they can be seen more easily. Don't try to wash them off.

The pen marks will start to rub off in time. They can rub off on your clothes or when you wash. Tell your radiographer if that happens. They can redraw them the next time you have treatment.

You may want to wear older clothes next to your skin in the treatment area. Or you can ask your radiographer after each treatment, to remove the marks with a wipe.

Find out about caring for your skin during radiotherapy

Last reviewed: 30 Oct 2023

Next review due: 30 Oct 2026

Planning your external radiotherapy

Your radiotherapy team carefully work out how much radiation you need to treat the cancer and exactly where you need it.

Radiotherapy masks or moulds

You might have moulds or masks made for you before you start radiotherapy. Find out about the different types and how they're made.

What is external radiotherapy?

External radiotherapy uses radiotherapy machines to aim radiation beams at a cancer. This destroys the cancer cells. There are different types of external radiotherapy.

Radiotherapy treatment for cancer

You might have radiotherapy to try to cure cancer or to help relieve symptoms. You might have it with other treatments such as chemotherapy or surgery.

Radiotherapy main page

Find out about cancer treatment with radiotherapy, including external radiotherapy, internal radiotherapy, side effects, radiotherapy for symptoms and follow up after treatment.

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