Radiotherapy uses radiation to treat cancer. Modern radiotherapy techniques mean that your team can target a very precise area containing the cancer. They also try to plan your treatment so that it causes as few side effects as possible. But any healthy cells in the treatment field are also affected and this causes side effects.
While radiation kills the cancer cells, the normal cells are usually able to recover. And your side effects generally get better over a few weeks.
Finding out about side effects
Before you start treatment your doctor will explain any possible side effects of the treatment. Knowing about the side effects can help you to prepare and manage any problems.
Ask about any possible long term side effects that the treatment may cause or anything else you might be worried about.
Side effects during treatment
Radiotherapy affects people in different ways, so it's difficult to predict exactly what side effects you will have and how bad they might be. Some people only have mild side effects but for others the side effects can be more severe.
Some general side effects include:
Tiredness and weakness
You might feel tired or lack energy when you're having radiotherapy. This may last for a few weeks after the treatment ends.
This can be because:
- your body is repairing damage to healthy cells
- you have low levels of red blood cells (anaemia)
- you're travelling to the radiotherapy department each day
Some people do keep working during treatment. Whether you can or not depends on how you feel. Rest if you need to and try to exercise when you can. This can help to reduce tiredness.
Some people get sore skin in the treatment area from radiotherapy. Your skin might:
- look red or darker
- become more sensitive
- be dry and itchy
- break and blister
The staff in the radiotherapy department can advise you on the best way of coping with this. They usually advise that you continue to use your normal moisturiser unless this begins to irritate your skin. Or use a simple non fragranced moisturiser and to be gentle with the area.
Continue to protect the treated area from the sun for at least one year after you have finished treatment. Your skin will be more sensitive, so use sunscreen with SPF 50 (sun protection factor 50).
Ask your radiographer if you have any concerns.
Loss of hair in the treatment area
Radiotherapy makes the hair fall out in the treatment area. It won't cause hair to fall out in other parts of your body.
Your hair might grow back a few weeks after treatment ends. If it's unlikely to your doctor should tell you this before you start treatment.
Other side effects
Other side effects that you may have depend on the area of the body being treated. Tell your doctor, nurse or radiographer about any side effects.
They can help you find ways of reducing the effects and coping with them.
Radiotherapy can cause many different side effects, such as tiredness. The side effects you get will depend on the area you're having treatment to, but there are some general side effects you might experience regardless of where your cancer is. This video is about the general side effects you might have.
On screen text: Tiredness and weakness
Martin (Radiographer): As the normal cells repair themselves from the treatment this can use a lot of the body's resources, causing tiredness.
David: After about four weeks, I started to get tired. The body was starting to weaken.
Laurel: I was tired, day and night. Getting up in the morning was like a chore. I couldn't talk for 5 minutes. I would just sleep and just sleep and just wake up and sleep again.
Martin (Radiographer): Listen to your body. Take rests if you need to. Try not to overdo things.
Laurel: Don't fight with yourself too much. Just like go at a pace and just work with your body. If you can't make it today, you can't make it today.
David: You've got to rest. You have to take the time to rest.
Mary: Just going for them small walks. They really do help you. And even if it is just walking around your house or just walking around the block.
Martin (Radiographer): Doing exercise can help with tiredness by helping you maintain energy levels.
Mary: Being outside, that's a big, massive thing as well because you're feeling the fatigue and I think getting outside, just getting a bit of fresh air that really, really did help me.
Martin (Radiographer): The tiredness you can expect to begin within the first few weeks of treatment. Once it reaches its peak, about two weeks after treatment it recovers quite quickly after that.
Mary: It's not forever. You're not going to be like this forever and I did have to tell myself that.
Laurel: Two months after treatment, I start to feel less tired and that was a way forward because things start to really improve.
On screen text:
- Rest and have short naps when you need to
- Drink plenty of water
- Eat a balanced diet
- Do some gentle exercise
- Get some fresh air
On screen text: Sore skin
Martin (Radiographer): The radiotherapy can cause soreness of the skin. This only affects the area that you are having treated. This usually starts to appear about two weeks after you start treatment. You may notice this becoming more red and may become more itchy and sore as treatment continues.
David: After about ten days I started to get red on the area that they were targeting and it just progressively got redder and redder.
Laurel: My skin was dry and at the back was just like this triangle shape thing where it was like, okay, I'm a woman of colour, but it was really, really black.
David: Wasn't too painful, it was sort of annoying, rather than painful.
Martin (Radiographer): After treatment’s finished, the skin will remain sore for up to two weeks, but then recovers quite quickly.
Laurel: I haven’t got no scarring now at all.
David: It was maybe three or four weeks and then all the blemishes disappeared front and back.
Martin (Radiographer): When you start treatment we would advise you to carry on with your normal skincare routine but as the side effects develop, then your team will advise you on which products you can use on the skin safely.
Laurel: When I'm washing myself I use a sponge and you're just literally as it were just squirt it down, you don't rub the skin at all because it's already damaged. Pat dry, don't rub.
David: I spoke to the hospital about it and it was them that recommended this cream to put on, just to alleviate the symptoms.
Martin (Radiographer): We'd recommend wearing loose clothing and keeping the treatment area covered up against the sun and wind.
Laurel: I had to change most of my wardrobe. I only wore cotton.
David: Wearing T-shirts, soft clothing, nothing that would rub.
Mary: It's important when you go outside to make sure that you do wear that headscarf, or you do wear a hat or whatever it is.
Laurel: I wouldn't go in the sun at all, at all because my skin was - I know it was too delicate.
On screen text:
- Don’t rub the area, press if it is itchy and dab your skin dry
- Don’t use perfume, perfumed soaps or lotions on the area
- Don’t shave the area
- Only use creams or dressings advised by your specialist or radiographer
- Wear loose fitting clothing
- Avoid strong sun or cold winds
- Make sure you wear sunscreen
On screen text: Hair loss
Martin (Radiographer): Radiotherapy can cause hair loss in the area that's being treated, whereas chemotherapy can cause hair loss all over the body.
Mary: 2 to 3 weeks after the radiotherapy, I was brushing my hair and loads came out on the brush. I knew it was going to happen, but it was just hard when it happened.
Martin (Radiographer): In most cases the hair will grow back. This can take a couple of months and the hair may have a slightly different colour or texture.
Mary: Mine did grow back and there's a lot of grey in it so I have to dye it. This is not my original colour. It's very slow growing back.
Martin (Radiographer): Use a simple soap to clean the area. Be gentle with the skin in that area and after washing pat the area dry with a soft towel.
On screen text:
- Radiotherapy can make hair fall out in the treatment area
- It won’t cause hair to fall out in other parts of your body
- Your hair might grow back a few weeks after treatment ends
- If your hair won’t grow back, then your doctor should tell you
- Don’t use perfume, perfumed soaps, or lotions on the area
On screen text: Your mental health
Laurel: I felt frustrated. Some days were really, really challenging where there were just tears without words.
Mary: It's a mixture of emotions. You feel angry and you feel frustrated. You lose your confidence.
Martin (Radiographer): Radiotherapy can cause a lot of emotions at various times during the treatment. You may feel sad or anxious or depressed, which is quite normal. It's good to talk to people about your experiences, whether that's your team at the hospital or friends and family.
David: I couldn't praise the team highly enough. Everybody that was involved were unbelievable and if it hadn't been for them, I just don't think I would have gotten through with it.
Mary: I did have a nurse as well and she had the experience of dealing with people that went through brain surgery, went through radiotherapy so it was just great that I could reach out.
Martin (Radiographer): Your team will be able to give you information about local patient support services that are available, that includes things like counselling and complementary therapies.
Laurel: A referral from the hospital counselling, which I attended for about a year.
Martin (Radiographer): There's also lots of support available online and in your local area.
Mary: I went on loads of different forums and I spoke to loads of different people and it really, really helped me. If I didn't do that, I don't think I would have got through most days.
Laurel: If you get a bit cranky or feel a bit low, go for it. But there's so much help out there and that's why I'm pushing forward like don't sit down in silence. It's the same thing, just get the help you need.
On screen text:
- There is help available – ask the hospital for support
- Talk to your friends and family about how you are feeling
- Ask about local support groups
- Your GP or hospital can provide counselling
- You can get help and support online through forums
If you're experiencing a side effect that hasn't been covered in this video, you can find more information on the Cancer Research UK website.
On screen text: For more information go to: cruk.org/radiotherapy/side-effects
Possible long term side effects
For many people, the side effects of radiotherapy wear off within a few weeks of the treatment ending. But for some people radiotherapy can cause long term side effects.
The possibility of long term side effects depends on the type of cancer, its size and position. It might also depend on how close the cancer is to nerves or other important organs or tissues.
It is important to ask your doctor, specialist nurse or radiographer about the possibility of long term side effects. Depending on the position of the cancer the possible long term effects might include:
- a change in skin colour in the treatment area
- red spidery marks on your skin (telangiectasia) caused by broken blood vessels
- a dry mouth
- breathing problems
- loss of ability to become pregnant or father a child (infertility)
- low sex drive
- erection problems (impotence)
- soreness and pain
- bowel changes
- bladder inflammation
- drainage channels to the arms or legs can become partly blocked resulting in swelling called lymphoedema