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This information is about how a radiotherapy mask is made. Perspex and plastic masks are often used when radiotherapy is given to the brain or the head and neck area.
This should ideally be read with our general information on brain tumours| or head and neck cancer|, as well as our information on radiotherapy|.
Radiotherapy is the use of 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 is usually for around 10-15 minutes at a time each day. You will not have to wear the mask at any other time.
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 around 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 are 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.
Strips of plaster of Paris being applied to the face to make a mould
View a large copy of the illustration of strips of plaster of paris being applied to the face to make a mould|
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.
A finished perspex mask
View a large copy of the illustration of a finished perspex mask|
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. Holes can be made around the mouth or nose to help you breathe more 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.
A plastic mesh mask
View a large copy of the illustration of a plastic mesh mask|
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 is based on our Making a radiotherapy mask fact sheet and has been compiled using information from a number of reliable sources including:
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