Making a radiotherapy mask
Perspex and plastic masks are often used when radiotherapy is given to the brain or the head and neck area. These masks are called radiotherapy masks.
This should ideally be read with our general information on brain tumours or head and neck cancer, as well as our information on radiotherapy.
We hope this information answers your questions. If you have any further questions, you can ask your radiographer, doctor or nurse at the hospital where you are having your treatment.
Radiotherapy is the use of high-energy x-rays (and other rays) to treat cancer. Radiotherapy has to be aimed very precisely to make sure that exactly the right area of the body is treated each time.
It's important that a person having radiotherapy lies still while the treatment is in progress. This is because any movement could change the area that gets treated.
When radiotherapy is given to treat tumours of the head and neck area or brain tumours, it is even more important to be as still as possible. To help with this, a radiotherapy mask (sometimes called a mould, a head shell or a cast) is made to be worn during the treatment. Once the mask is fitted, it is fixed to the radiotherapy treatment table. This ensures that your head and neck are held in exactly the right position for the treatment.
Wearing a mask reduces the possibility of any movement while the radiotherapy is given. The mask is only worn during the planning procedures and during the treatment itself, which usually takes about 10-15 minutes at a time each day. You will wear the same mask for planning and treatment. You will not have to wear the mask at any other time.
How a radiotherapy mask is made
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The mask is made in the mould room of the radiotherapy department by a mould technician or radiographer. The process of making the mask can vary slightly between hospitals but it usually takes about 30 minutes. One technique uses wet plaster bandages and the finished mask is made of perspex. The other technique uses a type of mesh plastic, which is moulded to fit the shape of your face.
If you have a beard, you will need to trim it or shave it off before the mask is made. You will also need to have your hair cut before the mask is made. This is to ensure that the shape of your face or head stays the same during treatment. If the shape changes, a new mask needs to be made, which can delay treatment.
If you're having a perspex mask, you may be given a swimming cap or some other covering to wear to protect your hair from the mould mixture.
Firstly, the mould technician will apply a cool cream or gel to your face. They then put strips of plaster of paris bandage on top of this. Holes are left around your nose and mouth, so you will still be able to breathe easily.
Plaster of paris gets warm as it sets. This is normal but it may make the process uncomfortable. Do not worry; it will not burn you. Once the plaster of paris has set (which will take about five minutes), the mould is taken off. A perspex mask is then made from this mould.
This technique uses a type of plastic that becomes soft and pliable (thermoplastic), when heated in warm water.
It is put on to your face so that the plastic gently moulds to fit your face exactly. It feels a little like a warm flannel. The mask has many holes in it so you will be able to breathe easily.
Once the mesh has moulded and become hard (which takes a few minutes), the mask is taken off. It is then ready to be used when you have your treatment.
Once the mask is ready, you may need to visit the mould room again so that adjustments can be made to position the mask correctly on the radiotherapy treatment table.
You may also have your treatment planned during this visit. Treatment planning ensures that the radiotherapy is aimed very precisely at the cancer. You will be positioned on a machine called a simulator or a CT scanner, which helps the radiographer plan the exact position you need to be in. Sometimes scans or x-rays are necessary to help with planning.
The doctor or radiographer may make a few ink marks on the mask. This makes it easier to position you correctly each time you come in for treatment. Radiotherapy planning can take more than one visit.
When you have the radiotherapy you will be lying down on a table below the radiotherapy machine. The mask is placed on your face and fixed to the table so your head doesn’t move during the radiotherapy. Treatment usually takes only a few minutes and is not painful. The staff will be close by to answer any questions you may have.
This section has been compiled using information from a number of reliable sources, including:
Khan. Treatment Planning in Radiation Oncology. 2nd edition. 2007. Lippincott Williams and Wilkins.
Souhami, Tobias. Cancer and its Management. 5th edition. 2005. Blackwell.
With thanks to: Peggoty Moore, Macmillan Specialist Radiographer; and the people affected by cancer who reviewed this information. Reviewing is just one of the ways you could help when you join our Cancer Voices network.
This information is dedicated to the memory of Mrs Vron Crew.