What is a radiotherapy mask?

For most types of radiotherapy to your brain, head or neck area, you wear a mask during each treatment. This is sometimes also called a mould, head shell or cast.

The mask is made to hold your head and neck still and in exactly the right position. This helps make your treatment as accurate and effective as possible. The mask fits tightly but should not be uncomfortable. You can breathe normally while you are wearing it.

We have more information about radiotherapy for head and neck cancers. We also have more information about radiotherapy for brain tumours including stereotactic radiotherapy for brain tumours.

Before the radiotherapy mask is made

After your mask is made, it can only be adjusted slightly. So there are some things you may be asked to do beforehand, to help make sure your mask fits well:

  • Dental work
    Before the radiotherapy mask is made, you may need to see a dentist to have your mouth and teeth checked. If some of your teeth are unhealthy, they may need to be removed or repaired. Dental work can change the shape of your mouth and face slightly. So, it is important this is done before the mask is made.
  • Mouth bites
    Some people are given a mouth bite to wear inside their mouth during radiotherapy. This holds your mouth and jaw in position, so the right area is treated. This can also help reduce side effects. Your radiotherapy team will tell you if you need a mouth bite. If you do, you also need to wear it while your mask is made.
  • Hair
    You do not usually need to have your hair cut before the mask is made. But if you have a beard, you should trim or shave it off. During your treatment, do not make big changes to your hairstyle or let your facial hair grow back. This can affect how well the mask fits. Wet shaving can irritate the skin during radiotherapy. Use an electric shaver if you need to shave.

How a radiotherapy mask is made

A technician or radiographer usually makes the mask in the radiotherapy department. The process of making the mask can be different depending on the hospital, but it usually takes about 30 minutes. You may need to take off some of your clothes and wear a hospital gown while it is being made. If you usually wear a wig or head scarf, you need to take these off too.

Masks are usually made using a type of mesh plastic. This is moulded to fit the shape of your head and neck. Less often, wet plaster bandages are used to make a mould, which is then used to make a clear plastic (Perspex®) mask.

There are two types of radiotherapy mask:

  • Mesh plastic mask – this is made using a type of plastic mesh that becomes soft when heated in hot water (thermoplastic).
  • Perspex® mask – this is made using a clear plastic called Perspex®.

Making a mesh plastic mask

Stage 1

You lie on a couch, similar to the one used for treatment. Your head rests on a plastic head rest. The technician or radiographer tries to make you as comfortable as possible. They heat the plastic mesh and put it onto your face, so it gently moulds to fit your head and neck exactly.

This feels a bit like a hot flannel. It will not harm you and it cools down very quickly. The plastic mesh has lots of holes in it, so you can breathe easily.

The first photo below shows the plastic mesh being placed onto a man’s face. The second photo shows the mesh being gently moulded to his face and around the sides and top of his head.

Plastic mesh being placed on the face

Plastic mesh being moulded to fit the face

Stage 2

You lie still for up to 15 minutes while the plastic mesh cools down and hardens.

Plastic mesh cooling and hardening on the face

Stage 3

The mask is then taken off and is ready to be used.

The first photo below shows the mask being lifted off a man’s face. The second photo shows the finished mask on the treatment couch.

Finished plastic mesh mash being removed from the face

Finished plastic mesh mask on the treatment couch

Making a Perspex® mask

A Perspex® mask is made in two stages. First, the technician or radiographer makes a plaster mould of your head and neck. Then they use the mould to make the clear plastic (Perspex®) mask for your treatment.

To make the plaster mould, they spread a cool cream or gel on your face to protect your skin. They also give you a swimming cap or other covering to protect your hair from the plaster mould mixture. They then put wet strips of plaster of Paris bandage on top. They leave holes around your nose and mouth, so you can breathe easily.

Plaster of Paris gets warm as it sets. This is normal and does not harm your skin, but it may feel uncomfortable. It takes about 5 minutes to set and then the mould is taken off.

They then make a Perspex® mask from the mould.

Radiotherapy masks and treatment

Once the mask is ready, your treatment can be planned. This may be straight after the mask is made, or you may need to come back for another appointment.

Treatment planning makes sure the radiotherapy is aimed precisely at the cancer. You may need to take off some clothes and wear a hospital gown. If you usually wear a wig or head scarf, you need to take these off too.

The radiotherapy team help you get into the same position as when your mask was made. The mask is gently placed over your face and fixed to the treatment couch, so your head and neck do not move. The mask should be tight but not uncomfortable. If it is uncomfortable, tell the staff so that they can try to adjust it.

You may feel very nervous about wearing the mask, or feel claustrophobic. You may want to bring some calming music or a relaxation podcast to listen to during your appointments. Most people cope well with the support of the radiotherapy team. If you are worried or uncomfortable, let them know so they can help you. Your doctor can give you medication to take before your treatment to help you relax. But this is not usually needed.

During treatment planning, the doctor or radiographer may make a few ink marks on the mask. You may also have a permanent mark made on your chest. This involves making a small scratch in the skin with a needle and some ink – the same way as a tattoo is made. If you are concerned about having permanent marks, let your radiographers know. They can discuss other options with you. These marks make it easier to get you into the same position each time you come in for treatment.

The treatment planning appointment usually takes 30 to 60 minutes. You do not need to wear the mask for the whole time.

When you have the radiotherapy treatment, you lie in exactly the same position on a couch below a radiotherapy machine. The mask is gently placed over your head and neck and fixed to the couch. Treatment can take 10 to 30 minutes and is not painful. Again, the team can see, hear and talk to you and are close by if you need them at any time.

Getting support

Macmillan is here to support you. If you would like to talk, you can do the following: