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Radiotherapy affects people in different ways, so it’s difficult to predict exactly how you’ll react to your treatment. Before you start, the staff will discuss the side effects of the particular treatment you’re having with you.
On this page, we discuss the general side effects of radiotherapy that you may experience, whichever part of the body you’re having radiotherapy to. Being aware of side effects in advance can help you cope with any that may develop. You may find it helpful to read this information alongside information about the specific type of cancer| you have.
External radiotherapy| tends to cause more general side effects than internal therapy|. It’s important to remember that most people will have only a few of the side effects mentioned here, and for many people they will be mild. There have been huge improvements in radiotherapy treatment, and severe side effects are very rare.
Most side effects of radiotherapy will continue for about 10-15 days after treatment has finished and then gradually begin to get better. For some people however, they may continue for a few weeks.
You may feel very tired| during your radiotherapy treatment. Tiredness (fatigue) can often be made worse by having to travel to hospital each day, or by other treatment such as surgery| or chemotherapy|. Listen to your body and, if necessary, allow yourself extra time to rest, perhaps by taking a nap. It may help if you spread chores out over the week, sit down to do them wherever possible and accept any offers of help. Tiredness can be a problem for several months after your treatment has finished.
Some people find that their treatment makes them feel sick| (nauseous), and sometimes they may actually be sick (vomit). This is most common when the treatment area is near the stomach. Your clinical oncologist can prescribe very effective anti-sickness (anti-emetic) drugs if this happens, and they may prescribe them anyway as a precaution.
Tell your clinical oncologist if you have any nausea or vomiting, and remember that it usually stops once treatment is over.
As always during treatment of any kind, it’s important to have a healthy diet| and drink plenty of fluids. At times you may not feel like eating or you might find that your eating habits change. It can be easier to have small snacks throughout the day rather than large meals. You may lose a bit of weight during radiotherapy, especially if you have radiotherapy to the head or neck| area. It’s important to try to maintain your weight throughout treatment, as the radiotherapy will have been planned on your body’s shape. Tell the radiotherapy staff if you’re having any problems with eating, as they can arrange for you to talk to the hospital dietitian.
Some people develop a skin reaction while having external radiotherapy. If this happens, it may begin after about 10 days.
How your skin reacts will vary depending on the amount of radiotherapy you have. People with pale skin may find that the skin in the treatment area becomes red and sore or itchy. People with darker skin may also find their skin feels itchy and becomes darker with a blue or black tinge. Sometimes the skin will get very sore and it may break and leak fluid, although this doesn’t happen very often. If your skin gets very sore, your treatment may have to be delayed for a short time to allow the area to recover, although this is rare.
The extent of the reaction depends on the area being treated and the individual’s skin. Some people have no skin problems at all. Your radiographers will be looking for these reactions, but you should also let them know as soon as you notice any soreness or change in skin colour.
Staff in the radiotherapy department will be able to give you advice on how to look after your skin in the treated area.
This will vary according to the part of the body that’s being treated and the dose of radiotherapy. You may be advised to use only tepid water and unperfumed soaps to wash the area, and not to soak too long in the bath. You can dry your skin by patting it gently with a soft towel or using a hairdryer blowing cold air, but you shouldn’t rub the area, as this may make it sore.
Perfumed soaps, talcum powder, deodorants and perfumes may also make your skin sore and shouldn’t be used at all. The staff at the hospital may suggest that you gently apply plain moisturisers, such as E45 cream or aqueous cream, to the area.
After your treatment, plain soap and plain moisturisers are often recommended. Aloe vera cream can sometimes help the skin to heal.
It’s important not to use any creams or dressings unless they have been prescribed or recommended by your clinical oncologist or radiographer.
It’s very important that any marks put on your skin to show the treatment area are not removed until the treatment has finished. If the marks do fade or disappear, don’t try to replace them yourself - tell the radiotherapy staff straight away.
Men who are having radiotherapy to the head and neck may be advised not to shave the area or to use an electric razor rather than wetshaving.
These restrictions apply only to the treatment area - the rest of your skin can be treated normally. Your skin may peel after the redness has faded, but it will gradually heal. Changes to the skin usually settle down 2-4 weeks after treatment has finished, but the area may stay slightly darker than the surrounding skin.
The skin in the treated area is very sensitive and needs protecting from the sun or cold winds. If you’re having radiotherapy to your head or neck, try wearing a hat or a silk or cotton scarf when you go outside.
For at least the first year after your radiotherapy, it’s very important to cover the treated area if you go out in strong sunshine. Wear clothes made of cotton or natural fibres, which have a closer weave and offer good protection against the sun. Even after this time, the area of treated skin will be more delicate than normal, so take extra care.
Use a suncream with a high sun protection factor (SPF) of at least 30 and cover the area with a hat or close-weave clothing. It’s important to remember that you can burn through clothing if you are out in hot sun for a long time.
You can swim as soon as any skin reaction has settled down, usually within a month of finishing treatment. If you are swimming outdoors however, don’t stay in the water too long and remember to use a waterproof suncream.
Loose-fitting clothes, preferably made of natural fibres rather than man-made materials, are more comfortable and less irritating to the skin. Avoid tight collars and ties if you’re having radiotherapy to your neck.
Shoulder straps and bra straps can cause irritation if they rub against treated skin. If your breast| area is being treated, you may be more comfortable not wearing a bra or wearing a vest instead.
Having radiotherapy causes hair loss within the treatment area. Hair loss can also happen where the radiation beam leaves the body (for example, on the back of the neck), as well as where it enters the body. Ask your clinical oncologist or radiographer to show you exactly where your hair will fall out.
Hair usually begins to fall out after 2-3 weeks. Hair should grow back after treatment finishes. This may take several months, although it depends on the dose of radiotherapy you have.
Your radiographer can tell you if any hair loss is likely to be permanent.
Our hair loss| section gives tips on covering it up and coping with the emotional effects.
Radiotherapy to some parts of the body may affect the bone marrow. This is the spongy material inside some of our bones and is where the different types of blood cells are made. If the doctors think this might happen to you, you will have regular blood tests during your treatment to check the number of cells in your blood (your blood count). If your blood count is low, you may feel tired and run down. If your blood count becomes very low (which is unlikely), you may need to have a short rest from treatment so that your blood cell levels can return to normal. You may also need to have a blood transfusion|.
It’s very important to let your doctors know if you feel very unwell, if your temperature goes above 38°C (100.4°F), or if you start feeling cold and shaky.
Stopping smoking| during and after radiotherapy is very worthwhile. Research has shown that it may make the radiotherapy more effective as well as reducing the side effects. It will also improve your general health and reduce your risk of developing other cancers.
Stopping smoking or even cutting down at such a stressful time can be very difficult, but do your best. If you want help or advice you can talk to your specialist, GP or a specialist nurse, who will be able to suggest ways of stopping. Organisations such as QUIT| also offer advice and valuable support.
All cancer treatments can result in long-term side effects. Modern ways of giving radiotherapy are designed to limit the chance of permanent side effects as much as possible, and very few people develop long-term problems. If you’re concerned about the risk of developing particular side effects from radiotherapy, it’s best to speak to your clinical oncologist before your treatment starts.
Here we discuss some of the long-term side effects that can occur, but they will depend on the part of the body that was treated, so you won’t necessarily experience all of them.
Long-term side effects can take months and sometimes years to develop:
Our sections about the long-term side effects of pelvic radiotherapy for men| and women| have more information about some of these side effects.
Radiotherapy can cause cancer, and a small number of people will develop a second cancer because of the treatment they’ve had. However, the chance of a second cancer developing is so small that the risks of having radiotherapy are far outweighed by the benefits.
If you’re concerned about your risk of developing a second cancer, discuss your worries with your cancer specialist.
Content last reviewed: 1 July 2011
Next planned review: 2013
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© Macmillan Cancer Support 2013
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