Side effects of radiotherapy
Radiotherapy destroys cancer cells but can also affect some normal cells. This is what causes the side effects you may get.
Most side effects usually disappear gradually after the treatment is finished. This can take a few weeks or longer. The staff looking after you will explain the side effects you’re likely to get and give you advice on coping with them.
Most side effects will depend on the part of the body the radiotherapy’s aimed at. But some are general side effects that can happen no matter which part of the body is being treated.
This is a common general side effect and is probably the main thing you’ll notice. It sometimes carries on for a couple of months after treatment has finished. It usually builds up as treatment goes on, especially if you’re travelling to hospital every day for your treatment.
You won’t have your usual amount of energy and you’ll need plenty of rest. Get plenty of rest, try to pace things and don’t overdo it. But try to get some gentle exercise (like short walks) as well. Being active increases your energy levels and helps keep up your muscle strength.
If you feel up to going out with your friends, there’s no reason why you can’t go. But let them know you might have to cancel plans at short notice if you’re not up to it. Ask your friends to keep in touch through text, email or social networking sites so you don’t feel you’re losing touch.
If you're still studying, you probably won’t be able to go to school or college during all your treatment, or you may have some home-schooling. Try not to worry about catching up. Schools and colleges are used to helping pupils who’ve been ill, and they can set up any extra help you need.
Skin changes in the treated area
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This is another common general side effect. Your skin may become flaky and dry, and it may be itchy or sore. If you’re fair-skinned it may go red, and if you’re dark-skinned it can get a blue or black tinge.
The radiographer or nurse will give you advice on looking after your skin in the treatment area. For example, you may be advised to gently pat it dry, and not to use perfumed soaps, deodorants and creams, as they can make your skin sore. You might be asked to moisturise the skin using a plain unperfumed moisturiser. Your radiographer can suggest creams that you might use. Skin changes usually settle down 2-4 weeks after treatment has finished, and you can swim as soon as any skin reaction has settled down. You still have to protect the skin in the treatment area from strong sunshine for about a year after radiotherapy. Wear cotton fabrics and use suncream of at least factor 30. Remember to use waterproof suncream if you’re swimming.
This can be a side effect of having radiotherapy to the tummy, the chest, or the head and neck area. Having small regular snacks throughout the day rather than three main meals will probably be easier for you. A dietitian can give you advice on the particular problem you’re having and help make sure you’re eating enough. Always let a doctor or nurse know if you have worries about eating or your weight.
Body-specific side effects
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Other side effects depend on the area of the body being treated, so have a look at the section that applies to you.
Tummy and pelvis (the area between your hips)
Radiotherapy given close to the tummy can make you feel sick. Your doctor will prescribe anti-sickness drugs for you to take regularly. Let your nurse or doctor know if they aren’t working, as there are different ones they can try. The sickness will go away when the treatment is over.
Radiotherapy to the tummy and/or the pelvis can cause tummy cramps and diarrhoea. You’ll be prescribed anti-diarrhoea tablets to take regularly until it settles down. It’s important to drink plenty of fluids when you have diarrhoea. Your radiographer or nurse will give you advice on any foods you should avoid until the diarrhoea stops.
Radiotherapy to the pelvis can also make you feel uncomfortable or sore when you wee (pass urine). It can also make you feel like you need to wee more often than usual. Let your doctor or nurse know if this happens. Drinking lots of fluids can help, and your doctor can prescribe painkillers to make it less uncomfortable.
Another side effect of radiotherapy to the pelvis is losing pubic hair, but it grows back a few months after your treatment is over.
You might find it difficult to swallow, have a cough or feel breathless. Eating soft foods will make it easier and feel more comfortable. You’ll be given advice on the kind of foods to eat. If you have a cough or feel breathless, always let your doctor or nurse know.
Head and neck
This can cause a sore throat and difficulty swallowing. Your doctor can prescribe liquid painkillers, and eating soft foods will make swallowing easier.
Radiotherapy to the brain causes hair loss after 2 or 3 weeks. Your hair will usually start to grow back again 2-3 months after radiotherapy is over. Sometimes it grows back a slightly different colour or texture than it was before. You can lose hair where the radiation beam leaves the head as well as where it enters. Your doctor or nurse will show you where your hair is likely to fall out. When the dose of radiotherapy is higher, the hair might grow back more thinly than before or there may be patches where the hair doesn’t grow back at all.
Losing your hair is difficult, but there are ways of coping with it until it grows back.
Our video shows Bengu telling her story of when she lost her hair during chemotherapy treatment. We also have more information about hair loss, which is written for people of all ages, not just young people.
Radiotherapy to the brain sometimes causes headaches, and it may make you feel a bit sick. Your doctor can prescribe medicines to help with these side effects and they’ll go away shortly after treatment is over.
A short while after treatment is over you may also get very sleepy (as if you want to sleep all day). This gets better by itself, but let your nurse or doctor know if you feel very tired or drowsy.
Treatments like radiotherapy that help cure cancer may sometimes cause other health problems years later. These are called late effects or long-term side effects.
Newer ways of giving radiotherapy are designed to limit the chances of late effects as much as possible. Doctors are always researching new ways of preventing or reducing problems linked to cancer treatments.
After your radiotherapy is over you’ll come back to the clinic for check-ups, usually for many years. Any health problems linked to the treatment you had can be picked up and treated early through these checks.
Possible late effects depend on the part of the body treated and the dose of radiotherapy you had. Your cancer specialist and specialist nurse will talk to you about any possible late effects.