Login to Pancreatic Cancer UK

Side effects of radiotherapy

Radiotherapy does cause side effects, although they affect everyone differently. Many people will only have mild side effects, and severe side effects are not common.

If you have chemoradiotherapy, you may also get side effects from the chemotherapy.

We have described the most common side effects below, but your doctor will explain the possible side effects before treatment starts, including anything you need to contact them about straightaway. You will have regular check-ups with them during your treatment.

Let the radiographers know as soon as you start to get any side effects. It’s normally possible to manage most of them, sometimes with medication. Side effects usually last for about one to two weeks after your treatment has finished, but some such as fatigue (extreme tiredness), can last for longer. Sometimes, side effects can get worse straight after treatment before they start to get better.

If you have any questions about side effects or how to manage them, speak to your doctor or nurse. Or call our specialist nurses on our free Support Line.

Fatigue (extreme tiredness)

Fatigue is a common side effect of radiotherapy for pancreatic cancer. Travelling to hospital every day can make it worse. Tiredness can last for several weeks or months after treatment has finished. Find out more about managing fatigue.

Nausea and vomiting

During radiotherapy, organs such as the stomach and bowel will get some of the radiation. This may make you feel sick (nausea).  A few people might actually be sick (vomiting). Nausea or vomiting may increase as treatment goes on, and last for a few weeks once treatment stops. Your nausea may be worse if you have chemoradiotherapy.

What helps?

Runny watery poo (diarrhoea)

You might get diarrhoea and, more rarely, tummy pains.

What helps?

  • Drink plenty of fluids to avoid getting dehydrated (where your body loses more water than it takes in).
  • Speak to your medical team if diarrhoea continues to be problem or is severe – for example if you have diarrhoea more than four to six times a day, or if you are not able to drink enough fluid to replace what you’re losing. They can give you tablets to control it.
  • Ask a dietitian at the hospital about any changes to your diet that might help.
  • Read our tips for coping with diarrhoea.

Problems with eating and drinking

Some people also find that they have indigestion or heartburn before and after radiotherapy. Discuss this with your medical team if it’s a problem – they might be able to give you medication to help.

You also might not feel like eating and may lose weight. Find out more about dealing with diet and weight loss.

Skin reactions

Some people’s skin can react to radiotherapy although this is rare. It may become drier and more rarely, sore, itchy or darker, often on your back. Any skin reaction will usually settle down two to four weeks after treatment finishes. Your medical team may advise you to use moisturiser and drink plenty of fluids to minimise the risk of skin problems. If you do get any skin reactions your medical team can give you advice on managing them.

What is radiotherapy and how does it work?

What are the advantages and disadvantages of radiotherapy?

Types of radiotherapy

Clinical trials for radiotherapy

How will I have radiotherapy?

Side effects of radiotherapy

Looking after yourself during radiotherapy

Check-ups after radiotherapy

Published July 2017

Review date July 2019

Information Standard