Planning your treatment

Before you can start your radiotherapy treatment, it needs to be carefully planned.

The radiotherapy department staff will explain what to expect. You will have scans of the area to be treated. This helps the radiotherapy team decide the exact dose of radiotherapy and area to be treated.

You may need other things done as part of the planning process. You must stay very still during radiotherapy and in a particular position. So you may need to wear a mould or mask on the part of your body being treated to help keep you still. This needs to be made before your treatment starts. It might feel uncomfortable but you won’t have it on for very long.

A small, permanent mark (tattoo) may also be made on the skin to show the exact place the radiotherapy should be directed.

Let your radiographers know if you’re worried about any part of the radiotherapy process. It’s important that you feel involved and comfortable to ask questions at any time.

Before you start your treatment

Before you start your treatment it needs to be planned. Planning makes sure that the radiotherapy is aimed precisely at the cancer so that it causes the least possible damage to the surrounding healthy tissue. All radiotherapy treatments are planned on an individual basis by your clinical oncologist, a physicist and sometimes by a senior or specialist radiographer.

Some people may need to have a mould or mask made before treatment planning.

First planning visit

Your first planning visit will take 30–60 minutes. The staff in the radiotherapy department will explain what to expect and they will also tell you beforehand if you need to prepare in any special way. It‘s important for you to feel that you’re involved in your treatment, so feel free to ask as many questions as you need to.

You’ll usually have a CT (computerised tomography) scan taken of the area to be treated. This helps your oncologist and physicist plan the precise area for your radiotherapy. Before your scan, you may be asked to remove some of your clothes (from the area of your body that will be treated with radiotherapy) and to wear a gown.

The CT scan takes lots of images from different angles to build up a three-dimensional picture. You may have an injection of dye into a vein when you have the CT scan. This allows particular areas of the body to be seen more clearly. You may also be asked to have a full or empty bladder for the scan.

Instead of a CT scan, some people have an MRI (magnetic resonance imaging) scan or occasionally a PET (positron emission tomography) scan to help with planning their treatment. An MRI scan uses powerful magnetic fields to give a very detailed picture of the area that needs treating. A PET scan uses low dose radioactive glucose (a type of sugar) to measure the activity of cells in different parts of the body. Your hospital team will tell you more about these scans.

During your scan, you’ll need to lie still on a hard couch (sometimes called a table). If you feel uncomfortable when the radiographers position you on the couch, let them know so that they can make you more comfortable. This is important because, once you’re comfortable, the details of your position will be recorded. You’ll need to lie in the same position on a similar couch for your treatment.

The information from the scan is fed into a planning computer, which will be used by your radiotherapy team to work out the precise dose and area of your treatment.

Before your planning appointment, you may be asked to follow some instructions that will help the radiographers get a clearer picture. For example, you may be asked to follow a special diet or to drink plenty of water.

Depending on the type of cancer you have, extra procedures might be needed as part of your planning treatment. If this is the case, you will be given information about them.

An icon of a green ring-binder calendar with the number 31 on it.

Radiotherapy moulds and masks

To help you stay still and in position during the radiotherapy, you may need to have a mould or mask made before planning starts. This is used to help keep you still so that the treatment is accurate and as effective as possible.

Moulds are used to keep a leg or arm, or other body part, still during treatment. Masks keep your head and neck area still during treatment and are often used for treatments to the brain or head and neck area. Sometimes the terms ‘mask’ and ‘mould’ are used interchangeably. Occasionally they are also called shells. They’re made of a plastic mesh or clear perspex.

Moulds and masks are commonly used for children having radiotherapy.

Your mould or mask should fit snugly. If you have a mask that fits over your face, it may feel claustrophobic. But remember, you won’t have it on for very long. Your radiographers will tell you how long your treatment will take.

We have more detailed information about how radiotherapy masks are made.

Skin markings

Once the treatment area has been decided, markings are made on your skin to pinpoint the exact place where the radiation will be directed. Usually, permanent markings are made (tattoos). They’re the size of a pinpoint and will only be done with your permission. It’s a little uncomfortable while the tattoo is being made, but it makes sure that treatment is directed accurately. If you’re concerned about having permanent tattoos, let your radiographers know. They can discuss alternative options with you. You may not have tattoos if you’re only having a single or short session of radiotherapy for symptom control.

If you have a mould or mask, any marks that need to be made will be made on the mould or mask rather than your skin.

Skin care

During your radiotherapy, you’ll need to take extra care of the skin in the area that’s being treated. This is because the treatment may cause a skin reaction. Before your treatment starts, the staff in the radiotherapy department will give you advice on how to look after your skin. This will depend on the type of treatment you’re having and the area of your body being treated.

Usually you’ll be asked to avoid using any deodorants, soaps, perfumes and lotions on the area being treated other than those advised by the radiographers. This is because some products may make any soreness worse.

If you shave in the area that’s being treated, you may be asked not to shave during your treatment or to use an electric razor instead.

If you swim, you’ll need to ask your specialist team if you should avoid swimming until after your treatment has finished. They will also tell you when you can go swimming again after your treatment.

Back to External beam radiotherapy explained

What is external beam radiotherapy?

You may have external beam radiotherapy if it isn’t possible to remove all the thyroid tumour, there’s a high risk or it coming back or it’s spread to other parts of the body.

Making a radiotherapy mask

During radiotherapy to the head and neck a mask is used to help you keep still so that exactly the right area is treated.

After treatment

It can take time for your body to recover after finishing treatment. Advice and support is always available.