Find out about radiotherapy moulds and masks and about the process of making them.
About radiotherapy moulds and masks
You might need to have a mould or mask made before your radiotherapy. The mould is also called a shell. The shell keeps the treatment area of your body still each time you have your radiotherapy. So your treatment will be as accurate as possible.
You might need a shell for radiotherapy to your head or neck or to an arm or leg. Moulds for the head or neck area are called masks.
Some types of mould are see through and others aren't. The radiographers might make marks on them. They use the marks to accurately line up the radiotherapy machine for each treatment. It is very important that you are in exactly the same position each time.
You might have the mould made in the mould room of the radiotherapy department or during your CT planning session. It takes between 10 to 45 minutes depending on the type of mould.
Preparing for a mould or mask
The mould is normally made directly against your skin. You need to wear clothing that you can easily take off from the area to be treated. You also need to take off any jewellery from that area.
You might need to take off make up. It may be helpful not to wear any. Or you could take along make up removing items as well as new make up to apply afterwards.
Having a lot of facial hair can make it difficult to make a head and neck mask. The radiotherapy staff will advise you on any hair issues at your planning session.
There are 2 ways of making masks. One way uses a plastic mesh that the technician moulds to the shape of your face and neck. The other method uses wet plaster bandages to make a perspex mask.
The process can vary slightly between hospitals.
Making a mesh plastic mask
A mould technician or radiographer makes the mask in the mould room of the radiotherapy department or during your CT planning scan.
This technique uses a special kind of plastic heated in warm water so that it becomes soft and pliable.
The technician puts the plastic on to your face so that it moulds to fit your face exactly. It feels a little like having a warm flannel put onto your face. You can still breathe easily, as the plastic won't cover your nose or mouth.
After a few minutes the mesh moulds and becomes hard. The technician takes the mask off. It is then ready for use.
The video below shows what happens when you have your mesh mask made:
Voiceover: Making a mesh mask for radiotherapy takes a few minutes.
Radiographer: I am just going to heat this up now if you just keep nice and still there and just want to close your eyes for us.
Voiceover: The radiographer softens the mask by putting it in warm water for a minute or two. When the radiographer puts the mask on to your face it will feel warm and damp. They then clip it to the bed that you are lying on. It takes a minute or two to dry into the shape of your face. The radiographers will mark the mask where the light lines are.
Radiographer: OK, you are just going to feel us pressing down on the mask there; you are doing really well are you still ok?
Voiceover: They use the marks on the mask to line up the machine each time you have treatment. The mask keeps you head still and makes sure that your treatment is directed at the cancer. They put your name on the mask and keep it in the radiotherapy department ready for your treatment.
Patient: They told me about the procedure, a mask being fitted, that it would be moulded to the shape of my face. Which they did, three lovely girls put my mind at ease sat me down heated the mask moulded it around my face, not an uncomfortable thing at all to go through.
Making a perspex mask
The technician may give you a swimming cap or some other covering to wear, to protect your hair from the mould mixture.
They apply a cool cream or gel onto your face. Then, they put strips of plaster of paris bandage on top of this. You will still be able to breathe, because they leave holes around your nose and mouth.
Plaster of paris gets warm while it is setting. This is normal and may make the process uncomfortable. It won't burn you though.
The plaster takes about five minutes to set and the technician then removes it. They make a perspex mask from this mould.
The mask fits snugly to your face and neck and has holes cut for your eyes, nose and mouth. It is ready to wear at your next visit.
The photo above shows how the mould fixes to the radiotherapy table while you are having treatment.
It may feel strange and claustrophobic at first. You may need to wear it for between 15 to 45 minutes.
Let the staff in the department know if you feel worried or anxious. They can make suggestions about what may help you to relax.
Arm or leg moulds
If you are having a mould for radiotherapy treatment to your arm or a leg, you have the same process as for a face mask.
The mould room may also need to make a personalised leg or arm rest for you, as well as the mould.