Side effects of radiotherapy

The side effects of radiotherapy for advanced gallbladder cancer tend to be mild.

These side effects usually start a few days after the radiotherapy begins. They can gradually get worse during the treatment. And they might get a bit worse after the treatment it ends. But 1 to 2 weeks after you finish treatment they usually start to get better.

Everyone is different and the side effects will vary from person to person. You might not have all of the side effects we mention.

Tiredness and weakness

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.

Feeling or being sick

Feeling or being sick can be severe. It can start straight after treatment and last for a few days. Anti sickness injections and tablets can control it. Tell your doctor or nurse if you feel sick. You may need to try different anti sickness medicines to find one that works.

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

Tips

  • Avoid eating or preparing food when you feel sick.
  • Avoid fried foods, fatty foods or foods with 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 are feeling sick.

Diarrhoea

Your poo (stool) may be very watery. It might be watery and have a strong smell. And you may need to poo more often or urgently. Drink at least 2.5 litres of fluid a day to help keep you hydrated. Let your doctor or nurse know straight away if the diarrhoea is severe or getting worse.

Ask your nurse about soothing creams to apply around your back passage (anus). The skin in that area can get very sore.

Loss of appetite

You might lose your appetite for various reasons when you are having cancer treatment. Sickness, taste changes or tiredness can all put you off food and drinks.

Tips

  • Eating several small meals and snacks throughout the day can be easier to manage.
  • Ask your doctor or nurse to recommend high calorie drinks to sip between treatments, if you are worried about losing weight.
  • You can make up calories between treatments for the days when you really don’t feel like eating.
  • Drink plenty of fluids even if you can't eat.
  • Don't fill your stomach with a large amount of liquid before eating.
  • Try to eat high calorie foods to keep your weight up.

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. 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.

Side effects of chemotherapy with radiotherapy

Chemotherapy combined with radiotherapy can make some side effects worse. Combining these treatments is called chemoradiotherapy.

Last reviewed: 
07 Feb 2020
  • External Beam Therapy
    Peter Hoskin
    Oxford University Press, 2012

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