Side effects of radiotherapy affect everyone differently. Many people will only have mild side effects. Severe side effects are not common. If you have chemoradiotherapy, you may also get side effects from the chemotherapy.
The side effects may include:
Ask your radiotherapy team about the possible side effects, and how they will plan your treatment to reduce these. Side effects can usually be managed, and you will have regular check-ups during treatment where you can discuss them. Let the radiographers know as soon as you start to get any side effects.
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.
Side effects usually last for a few weeks after your treatment has finished but can sometimes last longer. They may get worse after your final treatment before they start to get better.
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.
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 be sick (vomiting). Nausea or vomiting may get worse as treatment goes on, and last for a few weeks after treatment. It may be worse if you have chemoradiotherapy.
You might get diarrhoea because the stomach and bowel get some of the radiation during treatment.
You might not feel like eating and may lose weight. Keeping your weight stable may improve how you feel and help you cope better with pancreatic cancer and its treatment.
Read more about dealing with diet and weight loss.
Some people also find that they have indigestion or heartburn after radiotherapy. Talk to your medical team about this if it’s a problem. They might be able to give you medicine to help.
Sometimes SABR can cause tummy pain. This is usually worse after two weeks and settles down within six weeks. Your medical team can give you painkillers to manage it.
It’s important you tell your medical team about any pain after radiotherapy. They will check what’s causing it and how best to treat it.
Some people’s skin can react to radiotherapy although this is rare. The skin 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 suggest you use moisturiser to reduce the risk of skin problems. If you do get any skin reactions, your medical team can give you advice on managing them.
It is very rare, but there is a small risk of long term bowel damage from radiotherapy. This can happen months or years after treatment. Symptoms include severe tummy pain, persistent nausea and vomiting, vomiting blood, or poo like black tar. If you have any of these symptoms at any time, go to A&E straight away.
If you have any questions or concerns during or after treatment talk to your nurse or treatment team. You can also contact our specialist nurses on our free Support Line. They can answer questions about side effects and radiotherapy.
We have listed some of the references to the sources used to write this information. If you would like the full list of references, email us at publications@pancreaticcancer.org.uk
Updated January 2026
Review date January 2029
