Side effects of radiotherapy

Side effects happen because radiotherapy affects normal cells as well as cancer cells in the area being treated.

Normal cells are more able to recover than cancer cells, but they may suffer some damage because of the radiation. Most side effects are temporary, but some may be permanent.

The staff treating you will check how you are each day, but if you have any problems you should tell the radiographer or clinic nurse. An appointment can then be arranged with your specialist and/or breast care nurse if necessary.

Immediate side effects

• Radiotherapy to the breast doesn't usually make people feel unwell. However, your body will use a lot of energy over the course of your treatment so you may feel more tired than usual. This may affect what you feel able to do. The journey to hospital can be tiring in itself. Many people find they can manage their daily tasks as usual and some people continue to work full time. Others need more time to rest, so it’s important to take as much time as you feel you need.
• You may develop a skin reaction in the treatment area during or after radiotherapy, including redness, darkening, tenderness or itching of the skin. This usually happens 10 to 14 days after starting treatment. Your skin may peel or flake as treatment goes on, and there may be a red, sore, moist reaction. You may have aches, twinges or shooting pains in the breast area. These are usually mild, but can go on for some time after treatment is finished.
• During treatment you may notice that your breast or chest area appears swollen and feels uncomfortable. This usually settles within a few weeks after treatment.
• If you have radiotherapy after breast-conserving surgery, usually called wide local excision or lumpectomy, the breast tissue on the treated side may feel firmer, smaller and look slightly different from before.
• Radiotherapy to the armpit will make the underarm hair fall out on that side. Hair lost during radiotherapy does not usually grow back.
• Lymphoedema (swelling caused by a build up of lymph fluid in the tissues) can occur if the lymph system becomes damaged following radiotherapy to the lymph nodes in the armpit. This may mean the arm (on the affected side) becomes uncomfortable, swollen and heavy. If this happens, speak to your medical team as soon as possible for advice  about managing the lymphoedema.
• If you have treatment to the area around your collarbone (clavicle) you may develop a sore throat or discomfort when swallowing during or following your treatment. If this happens talk to your radiographer, specialist or breast care nurse. It may be helpful to take some simple pain relief in liquid form, particularly before eating, until the discomfort settles.

Longer term side effects

• Radiotherapy to the breast and armpit can cause tissue hardening. This is known as fibrosis and is caused by a build-up of scar tissue.
• After an injury or long term inflammation to the body, scar tissue can form in the affected area. This is also known as fibrosis. If radiotherapy causes severe fibrosis, the breast can become noticeably smaller as well as harder. You may be able to see tiny blood vessels under the skin. This is known as telangectasia.
• Sometimes part of the lung behind the treatment area can become inflamed, causing a dry cough or shortness of breath. This usually heals by itself.
• If your breast cancer was on the left side, the treatment area can cover some of the heart. If this is the case, your doctors will be careful to minimise damage to the heart.

Rare longer term side effects

• Your bones may be weakened, sometimes leading to rib and collarbone fractures.
• Nerves in your arm may be damaged, which may cause tingling, numbness, pain, weakness and possibly some loss of movement.

Although longer term effects can develop months or years after the end of radiotherapy, improvements with the technical equipment and accuracy in planning treatment mean that many of these effects are now much less common. Serious side effects are very rare and most people believe that the benefits of the treatment outweigh the risks. If you do experience any side effects, discuss them with the radiotherapy staff.

 

Content last reviewed March 2012; next planned review 2013