Planning radiotherapy for secondary breast cancer

Radiotherapy uses high energy x-rays to treat cancer cells.

The radiotherapy team need to plan your radiotherapy before you start treatment. This means working out the dose of radiotherapy you need and exactly where you need it.

You have your planning appointment in the hospital radiotherapy department. This can take from 15 minutes to 2 hours. 

You usually have a planning CT scan in the radiotherapy department.

The scan shows the cancer and the area around it. You might have other types of scans or x-rays to help your treatment team plan your radiotherapy. The plan they create is just for you.

Photo of a CT scanner

Your radiographers tell you what is going to happen. They help you into position on the scan couch. You might have a type of firm cushion called a vacbag to help you keep still.

The CT scanner couch is the same type of bed that you lie on for your treatment sessions. You need to lie very still. Tell your radiographers if you aren't comfortable.

Injection of dye

You might need an injection of contrast into a vein in your hand. This is a dye that helps body tissues show up more clearly on the scan.

Before you have the contrast, your radiographer asks you about any medical conditions or allergies. Some people are allergic to the contrast.

Having the scan

Once you are in position your radiographers put some markers on your skin. They move the couch up and through the scanner. They then leave the room and the scan starts.

The scan takes about 5 minutes. You won't feel anything. Your radiographers can see and hear you from the CT control area where they operate the scanner. 

Your treatment team can put all the scans together in a special computer to decide your radiotherapy plan.

Ink and tattoo marks

The radiographers make pin point sized tattoo marks on your skin. They use these marks to line you up into the same position every day. The tattoos make sure they treat exactly the same area for all of your treatments. They may also draw marks around the tattoos with a permanent ink pen, so that they are clear to see when the lights are low.

Photograph of radiotherapy tattoo marks

The radiotherapy staff tell you how to look after the markings. The pen marks might start to rub off in time, but the tattoos won’t. Tell your radiographer if that happens. Don't try to redraw them yourself. 

Head mask for radiotherapy to the brain

You will have a head mask (or mould) made if you’re having radiotherapy to the brain. This keeps your head still during your planning CT scan and while you have treatment. 

You have this made before you start your treatment.

Radiotherapy mask (mould)

Your radiographer or technician makes your mask in the radiotherapy department. They might call the mask a radiotherapy shell.

The mask covers your face, and the top and sides of your head. It attaches to the couch when you are lying down for the planning scan or radiotherapy treatment.

The process of making the mask can vary slightly between hospitals. It usually takes around 30 minutes.

Before making the mask

You need to wear clothes that you can easily take off from your neck and chest. You also need to take off any jewellery from that area.

Facial hair, long hair or dreadlocks can make it difficult to mould the mask. Your radiotherapy team will tell you if you need to shave or tie your hair back.

Making the mask

The technician uses a special kind of plastic that they heat in warm water. This makes it soft and pliable. They put the plastic on to your face so that it moulds exactly. It feels a little like a warm flannel and is a mesh with holes in so you can breathe.

After a few minutes the mesh gets hard. The technician takes the mask off and it cools down. You might need to have one more fitting to make sure it is exactly right.

You wear the mask for your planning CT scan. Your radiotherapy team keep the mask in the department for when you go back for treatment. You wear it for each treatment session.

Photograph of a stereotactic radiotherapy mask for treating brain, head and neck cancers

After your planning session

You might have to wait a few days or up to 3 weeks before you start treatment.

During this time the physicists and your radiographer doctor (clinical oncologist) decide the final details of your radiotherapy plan. They make sure that the area of the cancer will receive a high dose and nearby areas receive a low dose. This reduces the side effects you might get during and after treatment. 

Last reviewed: 
15 Mar 2021
Next review due: 
15 Mar 2024
  • Advanced breast cancer: diagnosis and treatment
    National Institute for Health and Care Excellence (NICE), 2009 (updated 2017)

  • 4th ESO–ESMO International Consensus Guidelines for Advanced Breast Cancer

    F Cardoso and others

    Annals of Oncology, 2018. Volume 29, Pages 1634–1657

  • External Beam Therapy (2nd edition) 
    Peter Hoskin
    Oxford University Press, 2012

  • SEOM clinical guidelines in advanced and recurrent breast cancer 

    J Chacón López-Muñiz and Others

    Clinical & Translational Oncology 2019. Volume 21, Issue 1, Pages 31–45

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