Side effects of radiotherapy

Tiredness is a common side effect and probably the main one you will notice. Tiredness is different for each person and does not happen straight away. 

After a couple of weeks of treatment, it is common to feel more tired than usual. Having other treatments (such as surgery or chemotherapy) or travelling to the hospital every day can also make you feel more tired. Tiredness may increase throughout treatment and continue for a while afterwards.

It is important to listen to your own body and allow extra time to rest. This can be by going to bed earlier or having naps during the day. It can also help to do some gentle exercise, such as short walks, as this will help increase energy levels.

If you feel up to it, there is no reason you can’t still go out with your friends. It may help to tell them you might have to cancel plans at short notice if you are too tired. You can also keep up with friends through social media or texts so you still feel involved.  

If you are studying, you will probably need some time off from school or university during your treatment. But you may be able to have some home schooling. Try not to worry about catching up. Schools and universities are used to helping students who have been unwell. They can set up any extra help you might need.  

Tiredness can continue for a few weeks or months. If it does not get better, talk to your medical team.

Some people develop a skin reaction during their treatment. This is dependent on the skin sensitivity, the area being treated, and the amount of treatment the skin receives. 

Some people don’t experience any skin problems at all and others find that their skin is affected in a similar way to sunburn. Skin can become dry, sore and itchy. Depending on skin colour, it can become redder or darker.

Skin reactions don’t generally happen straight away, but gradually build up over a period of time and can continue for a couple of weeks after the radiotherapy has finished. The radiographers will give you specific
advice about how to care for skin while on treatment. 

It can help to:

• wear loose cotton clothing
• wash skin gently with mild soap and water, and pat dry
• use unperfumed moisturiser
• protect skin from strong sunlight during and after treatment — always use factor 50 sun cream and wear a hat
• if your underarm is in the area that’s being treated use your normal deodorant, unless the skin is broken
• try not to shave the area being treated - if you feel you have to shave, use an electric shaver

If your skin becomes sore, flaky, or broken in areas, tell your team straight away. If you do get a skin reaction, it should get better within four weeks of treatment finishing.  

Radiotherapy may cause side effects that make eating difficult. Depending on what area of the body is being treated, it can become difficult or painful to swallow. It can cause nausea (feeling sick) or vomiting (being sick).

It may help to eat small snacks regularly throughout the day rather than large meals. Your medical team can give advice about nutrition, provide anti-sickness medicines to help with feeling and being sick and prescribe pain relief to help with pain when swallowing.

Some side effects from radiotherapy can be long-term or may happen many years after treatment has finished. This is called late effects of radiotherapy. 

These side effects will depend on the area of the body being treated, the dose of radiation given, and the age when it was given. 

Your clinical oncologist will discuss these late effects with you, and provide detailed information at the first introductory appointment, before consent for the treatment is given. 

After radiotherapy treatment, you will have regular check-ups to monitor any late effects. So, any problems linked to your treatment can usually be picked up and managed or treated early.  

A possible late effect of radiotherapy to the pelvis, or sometimes to the brain, is that it might affect fertility. Fertility means being able to get pregnant or make someone pregnant. Your specialist doctor and nurse will talk to you about this. You can ask about possible ways of preserving your fertility before treatment starts. 

Another important late effect is the risk of getting another cancer in the treated area. The thought of this can be scary. But it is important to remember that this is rare. It can help to talk this over with your doctor or nurse. They will advise you to have any new symptoms or lumps checked by your specialist team or GP.  

Your specialist doctor or nurse can explain what you can do to help reduce the risk of certain late effects. This usually includes making healthy lifestyle choices such as not smoking, protecting your skin from the sun, keeping physically active and eating healthily.  

This can be a lot of information to take in at the start of your treatment. Make a note of any questions you have as you think of them so that you can ask when you go back for check-ups. 

Radiotherapy given close to your tummy or pelvis (the area between your hips) may cause different side effects.  

Feeling sick 

You may feel sick. Your doctor will prescribe anti-sickness drugs for you. These usually control any sickness you have. Tell your nurse or doctor if they do not, as there are different ones they can try. Any sickness goes away when your radiotherapy finishes.  

Diarrhoea 

Radiotherapy to your pelvis may cause tummy cramps and diarrhoea. Your doctor will prescribe anti-diarrhoea tablets to take regularly until it settles down. It is important to drink plenty of fluids when you have diarrhoea. Your radiographer or nurse will give you advice on any foods you may need to avoid until the diarrhoea stops.  

Bladder irritation  

Radiotherapy to the pelvis can 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 or if your symptoms get worse. Your doctor can prescribe drugs to ease these symptoms and check for any urine infection.  

Try to drink 2 to 3 litres of fluids each day. Concentrated urine can irritate the bladder and make your symptoms worse, and drinking more fluids reduces this. Avoid drinks that can irritate the bladder. These include drinks with caffeine in them (tea, coffee, hot chocolate, cola), alcohol, fizzy drinks, acidic drinks (orange and grapefruit juice) and drinks with artificial sweeteners (diet or light drinks).  

Hair loss 

Radiotherapy to the pelvis will cause you to lose your pubic hair. It will usually grow back a few months after radiotherapy finishes.  

You might find it difficult to swallow, have a cough or feel breathless. Eating soft foods will make it easier to swallow. The radiotherapy team will give you advice on the kind of foods to eat. Your doctor can prescribe painkillers to make it more comfortable. If you have a cough or feel breathless, always let your doctor or nurse know.  

Your mouth and throat may become sore and you may have difficulty swallowing. Try to follow the advice from your radiographer or nurse about taking care of your mouth and keeping it clean. Your doctor can prescribe liquid painkillers. Your radiotherapy team will give you advice on foods to eat that make swallowing easier. Once your course of radiotherapy has finished, your mouth will gradually heal. Most people get back to eating normally after a few weeks.  

Radiotherapy to the head and neck may stop you making enough saliva. This means your mouth gets dry. Taking regular small sips of water can help. Your doctor can prescribe mouthwashes, lozenges, artificial saliva sprays or gels to help. Saliva washes your teeth and protects them from decay. 

Radiotherapy to the brain can cause different side effects. Common side effects include tiredness, itchy sore skin on your scalp, hair loss and headaches. Tell your doctor if you have headaches or feel sick. They can prescribe painkillers, steroids, or anti-sickness drugs to help. The side effects will usually improve gradually after treatment is over. 

Hair loss 

You will lose the hair in the treated area. You may also lose some hair on the opposite side of your head where the rays come out. The radiotherapy staff will show you where your hair is likely to fall out. They will give you advice on looking after the skin on your scalp. Your hair usually grows back within 2 to 3 months of finishing treatment. Sometimes, it grows back a slightly different colour or texture than before.  

Depending on the dose of radiotherapy, the hair might grow back thinner. Or sometimes there may be patches where the hair doesn’t grow back at all.  

Tiredness  

Tiredness is a common side effect. Try to balance getting plenty of rest with doing some gentle activity, like short walks. This can help give you more energy. Tiredness can sometimes take months to improve.  

Some weeks after treatment, you may feel extremely tired, as if you want to sleep all the time (called somnolence). Tell your doctor or nurse if you feel like this.  

Sometimes side effects get worse after treatment but this is temporary. Let your doctor know if this happens. It usually gets better by itself over the following weeks.