Planning radiotherapy for nasopharyngeal cancer
You have a planning session with your radiotherapy team a few days or weeks before you start treatment. First, you have a radiotherapy mould (shell) made of your head and neck.
Radiotherapy mould (shell)
You might need to have a radiotherapy mask or mould made before you start treatment. They can also be called shells. They keep the treatment area of your body still each time you have your radiotherapy. This is so your treatment is as accurate as possible.
Your radiographers may make marks on it. They use the marks to line up the radiotherapy machine for each treatment.
The process of making the shell can vary slightly between hospitals. It usually takes around 30 minutes.
Before making the shell
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 shell. Your specialist cancer nurse or radiotherapy team will tell you if you need to shave or tie your hair back.
Making the shell
A technician uses a special kind of plastic mesh that they heat in warm water. This makes it soft and pliable. They put the plastic on to your face, neck and chest so that it moulds exactly.
After a few minutes the plastic gets hard. The technician takes the shell off and it is ready to use.
The video below shows what happens when you have a mesh mask made. For head and neck cancer, the mask covers your neck and the tops of your shoulders as well as your head.
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?
Patient: Mmm
Voiceover: They use the marks on the mask to line up the machine each time you have treatment. The mask keeps your 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.
What happens at your planning session
The radiotherapy team plan your external radiotherapy before you start treatment. This means working out the dose of radiotherapy you need and exactly where you need it.
Your planning appointment takes 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.
Your radiographers tell you what is going to happen. They help you into position on the scan couch.
The CT scanner couch is the same type of bed that you lie on for your treatment sessions. You need to lie very still during the scan. You might also have a type of firm cushion called a vacbag to help you keep still. Tell your radiographers if you aren't comfortable.
Once you are in position on the scanner couch your radiographers move it 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 watch from the room next door and you can talk to them on an intercom if you need to.
Your treatment team puts all the scans together in a special computer to decide your radiotherapy plan.
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 radiotherapy 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.
