Side effects of radiotherapy for nasopharyngeal cancer

Most people have side effects from radiotherapy to the nasopharynx. The side effects usually appear gradually during your course of treatment. They are likely to be worse towards the end of your course. 

Over the 2 to 3 weeks following your treatment they start to slowly get better. Getting over a long course of treatment completely can take quite a few months.

There is a possibility of having long term or late side effects. These can be side effects that don't go away after finishing radiotherapy, or begin several months or years afterwards. Your doctor or radiographer will talk through the possible side effects with you before you start treatment.

Everyone is different and the side effects vary from person to person. You might not have all of the side effects mentioned below.

Possible side effects of radiotherapy

The side effects of radiotherapy to the nasopharynx can include:

You might feel tired during your treatment. It tends to get worse as the treatment goes on. You might also feel weak and lack energy. Rest when you need to.

Tiredness can carry on for some weeks after the treatment has ended but it usually improves gradually.

Various things can help you to reduce tiredness and cope with it, such as exercise. Some research has shown that taking gentle exercise can give you more energy. It's important to balance exercise with resting.

The skin in the area being treated may become red and sore. It may take 4 to 6 weeks for this to get better.

Using lotions, powders or creams on the treatment area might make things worse. It is important to get advice from the radiotherapy department before you use something to soothe your skin.

Radiotherapy to the nasopharynx damages the glands that produce your spit (the salivary glands). This can happen within a couple of weeks of starting your treatment. Your doctor might call a dry mouth from lack of saliva xerostomia (pronounced ze-ro-stome-ee-ah).

Some people say they make as much saliva as before, but that it is thicker and stickier. This can make it harder to chew and swallow.

Long term

After the treatment, you might have a permanently dry mouth. This can make eating and talking quite uncomfortable.

Your doctor can prescribe artificial saliva to keep your mouth moist. This is not just to make you more comfortable. You are more likely to get an infection or tooth decay if your mouth is dry. So you have to keep an eye on this, and have regular check ups with your dentist.

There is some evidence to suggest that having acupuncture might help with a dry mouth caused by radiotherapy to the head or neck. 

Newer radiotherapy techniques mean that the risk of developing a dry mouth in the long term is less than it used to be.

Most people who have radiotherapy for nasopharyngeal cancer get a sore mouth and throat. You might also have ulcers. Your mouth and throat are likely to become increasingly sore until after your treatment. And can take a couple of months to get better.

You might need strong painkillers such as morphine if your throat becomes very sore. Some people have these through a pump or skin patches. 

Your doctor might also give you a mouth gel that forms a protective coating over the inside of your mouth, a bit like a dressing. This can make your mouth less painful and make it easier to eat and drink.

Mouth care is very important with radiotherapy. Your nurse or radiographer might give you mouthwashes to use and will talk you through your mouth care plan. Do stick to this plan. Regular mouthwashes help to keep your mouth clean and avoid infection. Infection can make your mouth even more sore.

As your course of radiotherapy goes on, you might have difficulty chewing and swallowing because your mouth and throat are sore.

You can have a liquid diet if you feel this would help. So make sure you tell the staff in the radiotherapy department about any problems you are having. They can arrange for you to see a dietitian.

Feeding through a tube

Most people find they need feeding through a tube, to make sure they get enough calories. There are 2 ways of doing this. You can have either:

  • a tube up your nose and down into your stomach (a nasogastric tube)
  • a tube that goes through the skin into your stomach (a PEG tube)

Your nurse shows you and your relatives how to care for the tube and how to give the feeds.

Some people feel quite upset if they need to have tube feeding. It can feel as if another bit of normal life has been lost to you. But it is only temporary. Your health is the most important thing and you will feel a lot better if you are getting the nutrition you need for everyday living.

Good nutrition also helps you to recover better from your treatment. Eating can become a strain during this type of treatment and feeding through a tube takes away that extra stress.

Radiotherapy to the head or neck often affects taste.

People often say they have a metallic taste in their mouth with radiotherapy and some chemotherapy drugs. You might lose your sense of taste, or have strange tastes or dulled taste. Loss or changes of taste affect your appetite.  

In time, you are likely to recover fully from this. But some people might find their sense of taste is permanently dulled.

Radiotherapy for nasopharyngeal cancer often affects hearing. You might find it hard to hear soft sounds. Or you might find it hard to tell different sounds apart. 

Usually this is a temporary problem that happens during your treatment and recovery. But occasionally hearing loss or changes can be permanent.

You might be more likely to have hearing problems if you are having chemoradiotherapy. This is because the chemotherapy drug cisplatin can also affect hearing.

Radiotherapy can damage the nerve which controls the muscles that you use to open and close your mouth (trigeminal nerve). This make the muscles tighter, which makes it harder to open and move your mouth. 

This tightening (contraction) of the mouth muscles is called trismus. It can make it difficult to eat and brush your teeth. Your doctor or nurse gives you exercises to help if you have this side effect.

Radiotherapy to the neck can damage the thyroid gland.

Your doctor will check whether your thyroid is working properly after your radiotherapy treatment. If it isn't, you have to take medicines to replace your thyroid hormones.

If your radiotherapy reaches the pituitary gland in your brain, it can stop this gland making enough hormones. This is called hypo pituitarism.

These hormones affect your growth and sex drive. You have to take replacement hormones for the rest of your life if your pituitary gland is affected. This could happen years after your radiotherapy has finished.

After radiotherapy to treat a head and neck cancer, you are at risk of getting swelling called lymphoedema in your neck or face.

Lymphoedema in the head or neck area might also cause swelling of your tongue and other parts of your mouth.

Tell your doctor if you:

  • have any swelling in the head or neck area or a feeling of fullness or pressure
  • find it difficult to swallow
  • have changes in your voice

Possible side effects of chemoradiotherapy

Having chemotherapy with radiotherapy (chemoradiotherapy) can make some side effects worse.


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

Getting help

You usually have regular checks by your head and neck cancer team during your course of radiotherapy and for a couple of weeks afterwards. They can assess any side effects you have and give you advice and medicines to help. Between checks, do speak to your radiographer or nurse if you need help managing any side effects.

Very rarely, the side effects of radiotherapy can be particularly severe. If this happens, your doctor will stop your treatment to allow you to recover.

Last reviewed: 
22 Feb 2021
Next review due: 
22 Feb 2024
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  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.

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