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Radiotherapy

Having radiotherapy to the brain (prophylactic cranial irradiation)

Prophylactic cranial irradiation (PCI) means giving radiotherapy to the brain to kill any cancer cells that might have spread into the brain but are too small to see.

When you might have prophylactic cranial irradiation

Your doctor will suggest radiotherapy to the brain if you have small cell lung cancer with limited disease, and:

  • you are well enough

  • your cancer has responded to chemotherapy and radiotherapy (first line treatment)

You usually have up 10 treatments.

Some people with small cell lung cancer who have extensive disease might also be offered PCI. Research shows better outcomes for people with limited disease.

The planning CT scan

Before your radiotherapy you have a planning session and a planning CT scan.

Photo of a CT scanner.

The planning session takes between 15 minutes and 2 hours.

You also have a mask (shell) made that keeps your head very still.

Radiotherapy mask (mould)

Your radiographer or technician makes your mask in the radiotherapy department. They might call the mask a radiotherapy shell.

The mask covers your face, and the top and sides of your head. It attaches to the couch when you are lying down for the planning scan or radiotherapy treatment.

The process of making the mask can vary slightly between hospitals. It usually takes around 30 minutes.

Before making the mask

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 mask. Your radiotherapy team will tell you if you need to shave or tie your hair back.

Making the mask

The technician uses a special kind of plastic that they heat in warm water. This makes it soft and pliable. They put the plastic on to your face so that it moulds exactly. It feels a little like a warm flannel and is a mesh with holes in so you can breathe.

After a few minutes the mesh gets hard. The technician takes the mask off and it cools down. You might need to have one more fitting to make sure it is exactly right.

You wear the mask for your planning CT scan. Your radiotherapy team keep the mask in the department for when you go back for treatment. You wear it for each treatment session.

Photograph of a stereotactic radiotherapy mask for treating brain, head and neck cancers.

The radiotherapy room

Radiotherapy machines are very big and could make you feel nervous when you see them for the first time. The machine might be fixed in one position. Or it might rotate around your body to give treatment from different directions. The machine doesn't touch you at any point.

Before your first treatment, your ​​ will explain what you will see and hear. In some departments, the treatment rooms have docks for you to plug in music players. So you can listen to your own music while you have treatment.

Photo of a linear accelerator radiotherapy machine.

Before each treatment session

Your radiographers help you to get into position on the radiotherapy table. If you need to wear a mask for your radiotherapy, they will position the mask over your face and attach it to the table. The mask keeps your head completely still while you have treatment.

During treatment

You need to lie very still. Your radiographers might take images (x-rays or scans) before your treatment. This is to make sure that you're in the right position. The machine makes whirring and beeping sounds. You won’t feel anything when you have the treatment.

Your radiographers can see and hear you on a CCTV screen in the next room. They can talk to you over an intercom and might ask you to hold your breath or take shallow breaths at times. You can also talk to them through the intercom or raise your hand if you need to stop or if you're uncomfortable.

You won't be radioactive

This type of radiotherapy won't make you radioactive. It's safe to be around other people, including pregnant women and children.

Travelling to radiotherapy appointments

You might have to travel a long way each day for your radiotherapy. This depends on where your nearest cancer centre is. This can make you very tired, especially if you have side effects from the treatment.

You can ask your radiographers for an appointment time to suit you. They will do their best, but some departments might be very busy. Some radiotherapy departments are open from 7 am till 9 pm.

Car parking can be difficult at hospitals. Ask the radiotherapy staff if you are able to get free parking or discounted parking. They may be able to give you tips on free places to park nearby.

Hospital transport may be available if you have no other way to get to the hospital. But it might not always be at convenient times. It is usually for people who struggle to use public transport. Or who have any other illnesses or disabilities. You might need to arrange hospital transport yourself.

Some people are able to claim back a refund for healthcare travel costs. This is based on the type of appointment and whether you claim certain benefits. Ask the radiotherapy staff for more information about this and hospital transport.

Some hospitals have their own drivers and local charities might offer hospital transport. So do ask if any help is available in your area.

Side effects of radiotherapy to the brain

Radiotherapy to the brain can cause side effects. Let your doctor, nurse or radiographer know about any side effects that you have. Then they can find ways to help you.

Side effects usually get worse around the second week of treatment and will be at their worst at the end or just after your treatment course.

They generally last a number of weeks. Some might last for a few months after the treatment has finished.

Long term side-effects

There is a small chance that radiotherapy will affect your brain. Some people might have problems with memory, movement, or the ability to think or reason (cognitive function). If you are worried about this, talk to your doctor.

Last reviewed: 07 Feb 2023

Next review due: 07 Feb 2026

Treatment for lung cancer

Your treatment depends on several factors. These include what type of lung cancer you have, how big it is and whether it has spread (the stage). It also depends on your general health.

Treatment options for small cell lung cancer (SCLC)

A team of health professionals decides what treatment you might need. They also decide what treatment options you have. The type of treatment you have for small cell lung cancer will depend on the stage of your cancer.

Living with lung cancer

There is support available during and after treatment to help you cope. This includes support from your clinical nurse specialist, cancer charities, community services, and family and friends.

Research and clinical trials for lung cancer

Current research is looking at ways to improve the diagnosis and treatment of lung cancer.

Lung cancer main page

Lung cancer starts in the windpipe (trachea), the main airway (bronchus) or the lung tissue. Cancer that starts in the lung is called primary lung cancer.

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