Side effects of radiotherapy

Side effects tend to start a week after the radiotherapy begins. They gradually get worse during the treatment and for a couple of weeks after the treatment ends. But they usually begin to improve after around 2 weeks or so.

The side effects depend on which part of the body is being treated. They are usually mild if you are having radiotherapy to control symptoms.

These side effects vary from person to person. You may not have all of the effects mentioned.

Side effects can include:

You are likely to feel very tired during your treatment. It tends to get worse towards the end of your course of treatment. You might also feel weak and lack energy.

After a while you may need to sleep after each radiotherapy session. Rest when you need to.

Tiredness gets better once you finish treatment but it can carry on for a few days or weeks.

Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.

Your skin might go red or darker in the treatment area. You might also get slight redness or darkening on the other side of your body. This is where the radiotherapy beams leave the body. 

The red or darker areas can feel sore. Your radiographers will give you creams to soothe your skin. The soreness usually goes away within 2 to 4 weeks of ending the treatment. But your skin might always be slightly darker in that area.

Tell the radiotherapy staff if you notice any skin changes.

The liver is very near the stomach and bowel, so radiotherapy to this part of the body can cause sickness or diarrhoea.

Tell your nurse or doctor if you have sickness or diarrhoea, they can give you medicines to help reduce both these side effects.
Last reviewed: 
10 Dec 2018
  • EASL Clinical Practice Guidelines: Management of hepatocellular carcinoma
    European Association for the Study of the Liver
    Journal of Hepatology, 2018. Volume 69, Pages 182-236

  • Hepatocellular carcinoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow up
    A Vogel and others
    Annals of Oncology, 2018. Volume 29, Supplement 4, Pages 238-255

  • External Beam Therapy
    Peter Hoskin
    Oxford University Press, 2012 

Related links