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External radiotherapy for nasopharyngeal cancer

External radiotherapy uses x-rays to treat cancer cells. A large machine aims the x-ray beams at the cancer. External radiotherapy is the most common type of radiotherapy for nasopharyngeal cancer. 

You usually have a form of external radiotherapy called intensity modulated radiotherapy (IMRT).

IMRT shapes the radiotherapy beams to the cancer and different doses of radiotherapy can be given to different parts of the treatment area. This means the healthy tissue around the cancer gets lower doses of radiotherapy. This helps to reduce the risk of side effects.

How do you have external radiotherapy?

You have your treatment in the hospital radiotherapy department.

You go to the hospital for treatment once a day, from Monday to Friday, with a break at the weekends. The length of the course of treatment varies but it is usually between 4 and 7 weeks.


If you smoke, your doctor will advise you to give up before your treatment. Radiotherapy might not work as well and you may have more side effects if you continue to smoke.

The radiotherapy room

Radiotherapy machines are very big. They rotate around you to give you your treatment. The machine doesn't touch you at any point.

Before you start your course of treatment your therapy radiographers Open a glossary item explain what you will see and hear. In some departments the treatment rooms have docks for you to plug in your music player. So you can listen to your own music.

Photo of a linear accelerator

It is important to lie in the same position each time, so the radiographers may take a little while to position you on the couch and attach your mask to the couch. They make sure your mask feels comfortable.

Once you are in the right position the staff leave you alone in the room.

During the treatment

You need to lie very still. 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. They will ask you to raise your hand if you need anything but it is important to stay as still as possible. 

The treatment can take between 15 to 30 minutes.

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.

Stereotactic radiotherapy

Stereotactic radiotherapy is another form of external radiotherapy you might have for nasopharyngeal cancer.

This gives radiotherapy from many different angles around the body. All the radiation beams meet where the cancer is. So the cancer gets a very high dose of radiation and the areas around it get a much lower dose. This helps to reduce side effects. You may have this treatment in a single session.

You are more likely to have stereotactic radiotherapy for nasopharyngeal cancer that has come back near to where it started (local recurrence).

Travelling to radiotherapy appointments

Tell the radiotherapy department if you prefer treatment at a particular time of day. They can try to arrange this.

Car parking can be difficult at hospitals. It’s worth asking the radiotherapy unit staff:

  • if they can give you a hospital parking permit
  • about discounted parking rates
  • where you can get help with travel fares
  • for tips on free places to park nearby

If you have no other way to get to the hospital, the radiotherapy staff might be able to arrange hospital transport for you. But it might not always be at convenient times. To see if you're eligible they usually work it out based on your earnings or income.

Some hospitals have their own drivers or can arrange ambulances. Some charities offer hospital transport.

Side effects

Last reviewed: 
16 Feb 2021
Next review due: 
16 Feb 2024
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