Side effects of radiotherapy for secondary breast cancer

You may have some side effects from radiotherapy. Everyone is different and the side effects vary from person to person. You might not have all the side effects we mention. Any effects that you do have tend to be mild. 

Most 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.

Tiredness and weakness

You might feel tired during your treatment. It tends to get worse as the treatment goes on. You might also feel weak and lack energy. Rest when you need to.

Tiredness can carry on for some weeks after the treatment has ended but it usually improves gradually.

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

Feeling or being sick

You might feel sick if you have radiotherapy to the tummy area (abdomen) or brain. Your treatment team will give you anti sickness medicines to help.

Taking anti sickness medicine 20 to 60 minutes before having radiotherapy can sometimes help.

Let your treatment team know if you still feel sick as they can give you other medicines.

Reddening or darkening of your skin

Your skin might go red or darker in the treatment area. 

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.

Loss of hair in the treatment area

Radiotherapy to the brain always causes some hair loss. If you are having treatment to a particular part of your head, your hair only falls out in that area.

Whether or not your hair grows back depends on the type of radiotherapy you're having. For example, if you're having whole brain radiotherapy to treat your symptoms it's likely that your hair will grow back. A higher dose of radiation focussed in one area can cause permanent hair loss in that area. 

If your hair does grow back it may not be quite as thick as before and in some people can be patchy.

You may have questionnaires or quality of life forms to fill in. These can help you describe how you feel and the symptoms you are having. They can be very helpful for your doctor to look at and decide how to treat them.

Tell your radiographer, doctor or nurse if you have any side effects and they can find ways to help you.

  • ESMO International Consensus Guidelines for Advanced Breast Cancer

    F Cardoso and others

    Annals of Oncology, 2018. Volume 29, Pages 1634–1657

  • Advanced breast cancer: diagnosis and treatment
    National Institute for Health and Care Excellence (NICE), 2009 (updated 2017)

  • Cancer and its management (7th edition)
    J Tobias and D Hochhauser
    Wiley-Blackwell, 2015

  • Principles and Practice of Modern Radiotherapy Techniques in Breast Cancer
    A Haydaroglu and G Ozyigit

  • The role of radiation therapy in bone metastases management

    F De Felice and Others

    Oncotarget 2017, Volume 8, Issue 15, Pages 25691–25699

  • SEOM clinical guidelines in advanced and recurrent breast cancer  
    J Chacón López-Muñiz and Others
    Clinical & Translational Oncology 2019. Volume 21, Issue 1, Pages 31–45

Last reviewed: 
11 Mar 2021
Next review due: 
11 Mar 2024

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