Radiotherapy side effects

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.

Everyone is different and the side effects vary from person to person. You may not have all of the effects mentioned.

Reddening or darkening of your skin

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. This may start after your radiotherapy treatment is completed. Your radiographers may 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.

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.

Loss of body hair

You might lose any body hair that is in the treatment area. This will grow back after your treatment has finished. 

Diarrhoea

Radiotherapy can inflame the lining of your bowel if you have had radiotherapy to your tummy (abdomen). This can cause diarrhoea. You may also have:

  • griping or cramping pain
  • an increase in wind
  • feeling you need to go to the toilet urgently
  • some mucus or blood in your poo (stool)

It’s important to drink plenty if you have diarrhoea. Your doctor or specialist nurse can prescribe tablets to help slow down your bowel if you need them. This should help reduce the number of times you have diarrhoea. Your nurse or radiographer may also advise you about making changes to your diet while you have diarrhoea, such as a low fibre diet.

Ask your nurse or radiographer for soothing creams to apply around your back passage (anus). The skin in that area can get very sore and might break if you have severe diarrhoea.

In the few weeks after your treatment, the diarrhoea should gradually get better. Let your doctor know if it continues.

Feeling sick or being sick

You might feel or be sick if you have had radiotherapy to your tummy (abdomen). Some people who have had extended field radiotherapy might also get this side effect.

Anti sickness injections and tablets can control it. Tell your doctor or nurse if you feel sick. You might need to try different anti sickness medicines to find one that works.

Contact your doctor or nurse straight away if you have been sick more than once in a day.

Tips

  • Avoid eating or preparing food when you feel sick.
  • Avoid foods that are fried, fatty, or have a strong smell.
  • Drink plenty of liquid to stop you from getting dehydrated.
  • Relaxation techniques help control sickness for some people.
  • Ginger can help – try it as crystallised stem ginger, ginger tea or ginger ale.
  • Fizzy drinks help some people when they’re feeling sick.

Possible long term side effects

Most side effects gradually go away in the weeks or months after treatment. But some side effects can continue or might start some months or years later.  

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  • Hodgkin’s Lymphoma: ESMO clinical practice guidelines for diagnosis, treatment and follow-up
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    Annals of Oncology, 2018, 29 (Supplement 4)

  • Perez and Brady's Principles and Practice of Radiation Oncology
    EC Halperin, CA Perez and LW Brady
    Lippincott Williams & Wilkins, 2008

Last reviewed: 
01 Oct 2020
Next review due: 
01 Oct 2023

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