Side effects of radiotherapy

You may develop side effects while you’re having radiotherapy. These usually improve in the weeks and months after treatment finishes. Your health care team will discuss possible side effects with you. Let them know if you have any side effects, as there are often ways to help.

Side effects you may have include:

After radiotherapy, some people may develop swelling known as lymphoedema. This happens because the lymph nodes and vessels can become damaged by the radiotherapy. If lymphoedema develops, it can’t be cured but it can often be treated and managed.

A small number of people will develop a second cancer because of the radiotherapy treatment they have had. However, the chance of a second cancer developing is so small that the risks of having radiotherapy are far outweighed by the benefits.

Let your health care team know if you notice any of these changes as there are lots of ways in which they can be managed.

Side effects of radiotherapy

You may develop side effects over the course of your treatment. These side effects will usually gradually disappear over a few weeks or months after treatment is finished.

Your doctor, nurse or radiographer will discuss this with you so that you know what to expect. Let them know about any side effects that you have during or after treatment. There are often things that can be done to help.

Hair loss

Hair will only fall out in the area being treated by radiotherapy, so the treatment for soft tissue sarcomas will not make the hair on your head fall out. The hair that is lost may grow back after the treatment has ended, but it is often lost permanently.

Skin care

Some people develop a skin reaction similar to sunburn. Pale skin may become red and sore or itchy, and darker skin may develop a blue or black tinge. Your radiographers or nurses will give you advice on how to look after your skin.

Tiredness (fatigue)

This is a common side effect and may continue for months after treatment finishes. During treatment, you will need to rest more than usual, especially if you have to travel a long way for treatment each day. But it’s good to do gentle exercise, such as walking, when you feel able. Once your treatment is over, gradually increase your activity and try to balance rest periods with some physical activity. This will help you build up your energy levels.

Feeling sick (nausea)

Some people find that their treatment makes them feel sick (nausea) and, sometimes, they may actually be sick (vomit). This is most common when the treatment area is near the stomach or bowel. If you do have nausea and vomiting, they can usually be effectively treated with anti-sickness drugs (anti-emetics). Your doctor can prescribe these for you. If you do not feel like eating, you can replace meals with nutritious, high-calorie drinks, which are available from most chemists and can be prescribed by your GP.


Long-term side effects

After radiotherapy, some people may develop swelling known as lymphoedema. This happens because the lymph nodes and vessels can become damaged by the radiotherapy. Lymph fluid, which circulates around the lymphatic system, is unable to pass along the vessels and builds up, causing swelling. If lymphoedema develops, it can’t be cured but it can often be treated and managed.

To help prevent lymphoedema, you should try to avoid getting any infection or inflammation in the area that has been treated with radiotherapy. You should try to avoid cuts or grazes in the area and use a moisturiser if your skin gets dry.

Radiotherapy to a joint, such as the knee or elbow, may cause it to become stiff. It is important to keep the joint mobile by using it and doing regular exercise before, during and after treatment to help prevent stiffness.

A small number of people will develop a second cancer because of the radiotherapy treatment they have had. However, the chance of a second cancer developing is so small that the risks of having radiotherapy are far outweighed by the benefits. To reduce the risk, radiotherapy is very carefully planned and improvements in the way radiotherapy is given mean that the risk of developing a second cancer is very small.

You can talk to your cancer specialist if you are concerned about your risk of developing a second cancer.

Back to Radiotherapy explained

Who might I meet?

You will meet many different specialists before, during and after radiotherapy treatment.