Radiotherapy: planning your treatment

Radiotherapy treatment is carefully planned for each patient individually.

Planning usually takes place in a CT scanner. This provides an exact mock-up of the treatment position. The radiographers will explain what will happen during planning and carry out any preparation you may need. This scan will give your doctor and radiographers a detailed picture of the area that needs treatment.

The radiographers and physicists (who are specialists in the subject of radiation) calculate the dose of radiation you will be given. This is usually carried out with the help of computers.

The doctors will use your previous X-rays or scans to help them plan your treatment. Any extra preparation or procedures will be explained to you.

Treatment planning sessions may last for 30 minutes and sometimes up to an hour. Ask your radiographer how long each session will be.

If you are to have radiotherapy to your head or neck you may have an extra step in your planning process – the making of a shell.

What is a mask?

If you are having treatment to your head or neck you will need to wear a special mask to keep your head still. The mask will need to be worn for your planning CT scan and your treatment. The mask is made of a perforated sheet of thermoplastic and keeps you from moving during treatment. Any marks to guide the radiographers can then be drawn on the mask and not on your skin.

You will be given an appointment to attend the mould room. The technicians or radiographers will explain what they are going to do and what you need to do to help them.

You will be positioned on a couch; a sheet of thermoplastic will have been warmed in a water bath to make it flexible. It will be laid across your face and neck, and gently pressed into position around your features. It will feel warm and a little damp but is not an unpleasant sensation – a bit like holding a warm cloth on your face. Your mouth and nose will be covered but you will be able to breathe normally through the perforations.

A well fitting mask is difficult to make if you have long hair or a beard or moustache, so you may be asked to tie your hair back and shave any facial hair before your appointment at the mould room.

Dates and times

How soon the planning stage of your treatment will begin depends on the reason for your radiotherapy. Your first appointment may be a few days or weeks after you first saw the clinical oncologist. When radiotherapy is part of a combined treatment plan (with surgery or chemotherapy), you may be given dates for your radiotherapy some time ahead.

You may be given more than one appointment for treatment planning. These sessions can last for 30 minutes, and sometimes up to an hour. Ask your doctor or radiographer how long each session will be.