Radiotherapy can cause some side effects, such as a sore mouth, throat or skin. Side effects can be mild or more severe. This depends on the size of the area being treated and the length of your treatment. They are usually more severe if you have radiotherapy combined with chemotherapy (chemoradiation).
Side effects usually begin to develop after 2 weeks of radiotherapy. They may continue for about 2 weeks after treatment ends before starting to get better. Most people notice that their side effects have improved about 4 to 6 weeks after treatment finishes.
Radiotherapy can cause some side effects after treatment has finished. These are called late effects and can be temporary or permanent.
Before you start radiotherapy, someone from your healthcare team will discuss your treatment with you so you know what to expect. This could be your cancer doctor, nurse, speech and language therapist (SLT), dietitian or radiographer. Tell them about any side effects you have during
, or after treatment. There are often things that can help.
Radiotherapy often makes people feel tired. Tiredness may get worse as treatment goes on.
If you are having radiotherapy alongside other treatments, such as surgery or chemotherapy, you may feel more tired.
But there are things you can do to help, such as:
- get plenty of rest
- do some gentle exercise, such as short walks
- eat a healthy diet and drink plenty of fluids
- ask others for help with everyday jobs.
After treatment finishes, you may continue to feel tired for weeks or months. If it does not get better, tell your cancer doctor or specialist nurse.
We have more information about coping with tiredness (fatigue).
The skin in the area that is treated may:
- feel sore or itchy.
Your radiographer or specialist nurse will give you advice on taking care of your skin.
If your skin becomes sore or itchy or changes colour, tell them straight away. They can give you advice and treatments if needed.
Skin reactions should get better within 4 weeks of treatment finishing.
During your treatment, you are usually advised to:
- wear loose-fitting clothes made from natural fibres, such as cotton
- wash your skin gently with mild, unperfumed soap and water and gently pat it dry
- avoid rubbing the skin
- avoid wet shaving
- avoid hair-removing creams or products, including wax
- follow your radiotherapy team’s advice about using moisturisers
- protect the treated area from the sun.
The lining of your throat may become swollen, sore and inflamed. This may make it difficult to swallow. Your doctor can prescribe liquid painkillers to help with this. Try to take these before meals to make eating easier.
Your speech and language therapist (SLT) will talk to you about any swallowing or eating problems you may have. It is important to try to keep eating and drinking for as long as possible during your treatment.
You may cough when you eat and drink. Sometimes this can be a sign that food and drink is going down the wrong way (into the windpipe). This can cause a chest infection.
When to contact to your SLT
Eating and drinking
Your team will give you advice on foods that are easy to swallow. They may also give you nutritious or high-calorie drinks.
Most people manage to eat soft, moist foods while their throat is sore. Some people can only manage a liquid diet.
The soreness usually lasts for a few weeks after radiotherapy has finished. But some problems may continue for longer, depending on the area treated.
Some people find the soreness stops them eating or drinking enough. This is more common if you have radiotherapy and chemotherapy at the same time (chemoradiation).
We have more information on eating problems.
If you are not eating and drinking enough, your doctor might suggest you have nutritional support so that you do not lose too much weight. This means you have liquid food that contains all the nutrients you need. You will have this through a feeding tube that goes into your stomach. You can also have liquids and medicines through the tube.
If doctors think you might have problems eating, they may suggest putting in a feeding tube before you start treatment.
Nutritional support can:
- prevent weight loss and make sure you get enough fluids and nutrients
- help you feel less weak or tired
- make you feel less stressed about having to eat
- allow the sore area to heal and help you recover faster
- allow you to eat smaller amounts when eating is uncomfortable
- give you enough calories to help prevent you needing any breaks in treatment.
Your SLT will assess whether you can still swallow food and fluids safely while you have a tube in. If you swallow safely, you will still be encouraged to eat and drink normally with a tube in place. This will happen even if you can only manage small amounts at a time.
When treatment has finished, you are usually encouraged to stop using the tube as soon as it is safe.
It is important to follow the advice of your healthcare team when you have a feeding tube in.
Radiotherapy to the larynx may affect the salivary glands. This can make you produce less saliva. The lining of your mouth and throat can become dry. This can make eating and speaking difficult.
Saliva helps keep your mouth clean. This means it is important to brush your teeth with a soft toothbrush twice a day.
You can also use mouthwashes, but make sure you follow any instructions from your specialist nurse or doctor.
Drinking sips of water regularly can help keep your mouth moist. Your cancer doctor can give you artificial saliva sprays and gels to help. You are less likely to get an infection if your mouth is moist.
You may have a dry mouth for several months after treatment has finished. Sometimes, it can be permanent.
This usually depends on the size of the area being treated. Your doctor will be able to tell you what to expect.
Radiotherapy can change the consistency of your saliva. It may become thicker, stringy and sticky, like mucus.
The mucus does not flow as well as normal saliva, so it may build up in the mouth and throat.
You might need to spit often to get rid of the mucus, so it is a good idea to always have tissues with you. Rinsing your mouth and drinking water regularly can also help.
If you have a build-up of mucus, your cancer doctor or specialist nurse may suggest you use a nebuliser. This is a small machine that changes liquid medicine into a fine mist of fluid, which you inhale. It can help to loosen the mucus.
If your sleep is disturbed by coughing, using a nebuliser before bed may help. A nebuliser may also help if you have problems swallowing or a dry mouth and throat.
Your voice may already be hoarse, and this could get worse during radiotherapy. Your cancer doctor or speech and language therapist (SLT) will tell you about the risk of permanent voice changes.
If your voice is hoarse and weaker than before, try not to strain it, and avoid smoky places.
Your voice should slowly get better and stronger after radiotherapy has finished. This may take several weeks.
Your SLT can advise you on how to look after your voice during treatment. They can also suggest voice exercises to speed up your recovery.
You may not feel like eating if your mouth is sore. The soreness may be worse towards the end of radiotherapy and in the first 2 weeks after treatment has finished.
It is important to try to eat, even if you do not feel like it. If your mouth is very sore, it can help to take painkillers before you eat.
You can also see a dietitian. They may suggest you have some high-calorie or nutritious drinks until your appetite returns.
Radiotherapy may cause swelling in your throat. Very rarely, this can cause breathing problems, which need treatment straight away.
If you develop difficulty breathing, or if your breathing sounds different, tell a doctor or contact the hospital straight away.
Very rarely, you may need an operation to help you breathe. This is called a temporary tracheostomy.