Radiotherapy side effects

Mild (non-serious) side effects are common, during or after radiotherapy. The side effects depend on which area of the body is treated.

Your radiation oncologist will take care to reduce the chance of serious side effects.

If you are concerned about any side effects, it is important to talk to your treating team.

When side effects can start

Side effects are most likely to appear 10 to 14 days after you start treatment. Most acute side effects disappear within one month after treatment.

You may still develop some side effects months after you finish treatment.

Fatigue or tiredness

It is normal to feel tired during radiotherapy. Be prepared to feel more tired as your radiotherapy progresses. This is especially true if you have had recent chemotherapy.

Fatigue can last for months after you finish treatment.

Prevention/Treatment

Regular exercise can reduce the fatigue radiotherapy causes, but allow yourself time to rest. Even if you don’t feel you have the energy to exercise, try and do what you can. Read about fatigue and ways to reduce it.

Skin changes

Radiotherapy can affect the skin in several ways.

Skin is dry, red or itchy

Your skin may become dry, red and itchy, like sunburn. This may start as early as the second week of treatment and gradually become more obvious. Usually the problem disappears completely between 2 and 4 weeks after you finish treatment.

Skin changes colour

Radiation to your nipple and areola can cause the skin to become paler in colour. It may also become darker ('pigmentation').

Like dry or red skin, this usually improves between 2 and 4 weeks after you finish treatment but can be a permanent change.

Skin becomes thicker

The skin in the treated area may become tougher or thicker after treatment.

If your breast tissue is treated, this can cause mild to moderate breast firmness. This does not usually need treatment. Significant change is not common but may cause your breast shape and size to change.

When to contact your doctor

Tell the radiotherapy or nursing staff if:

• you develop a skin reaction
• your skin becomes sore and broken down, weeping or bleeding.

Prevention/treatment

You can reduce the effects of radiation on your skin. Read Caring for your skin during radiotherapy.

Sore throat or swallowing problems

Treatment to the area around the collarbone and breastbone can cause a sore throat or discomfort when you swallow.

When to contact your doctor

If this affects your eating and drinking, or causes weight loss, talk to your specialist or breast care nurse.

Prevention/treatment

Your specialist or breast care nurse may prescribe:

• a mild painkiller before each meal, or
• a mouthwash which will numb your mouth and throat, making it easier to eat and swallow.

Shoulder stiffness

Radiotherapy to the breast, shoulder and arm/armpit area can make your shoulder stiff.

When to contact your doctor

Contact your doctor if you are having pain or difficulty doing regular activities.

Prevention/treatment

It is important to do shoulder exercises during and after radiotherapy.

Pain and aches

Some people experience tenderness and swelling in the breast during and after radiotherapy treatment. Skin irritation can also be uncomfortable.

You may feel aches, twinges or sharp pain in the treated area. This is usually mild, but can continue for months, slowly becoming less intense.

It should settle after your radiotherapy treatment is finished, once the skin heals and any breast swelling settles.

When to contact your doctor

Tell the radiotherapy nursing staff if you develop any skin reactions or discomfort during treatment. They can give you advice on skin care.

Prevention/treatment

Wearing a soft, supportive bra or vest often helps to reduce the discomfort from swelling. If the swelling does not settle within a few weeks after you finish treatment, contact your treating team. You may need to be assessed by a lymphoedema specialist for ongoing management.

Continue your arm and shoulder exercises during radiotherapy and for several months after, to help minimise stiffness.

Swelling and tenderness

Radiation therapy can cause the tissue to swell in the area where you have treatment. This can make your breast, chest, arm or armpit (‘axilla’) tender and sore.

If your treatment is for metastatic breast cancer, you may experience swelling in other areas where you have radiotherapy.

When to contact your doctor

If swelling continues after you finish treatment, you may have damage to the lymph system. This can cause lymphoedema, and you need an assessment and treatment. Contact your treating team for a referral to a lymphoedema specialist.

Prevention/treatment

If you are diagnosed with lymphoedema, find out about Lymphoedema treatment and Compression garments for lymphoedema.

Less common side effects of radiotherapy

Skin blisters or peeling

The area where you have radiation can sometimes blister or peel. This is most likely towards the end of radiotherapy or after it has finished.

When to contact your doctor

Contact your treating team if you are experiencing pain, or the blisters are not healing and weeping. It is important you have the right dressings to prevent an infection.

Prevention/treatment

Your radiation oncologist can help you with this, and the skin normally heals a few weeks after treatment ends.

Broken blood vessels (spider veins)

You may notice small patches of blood vessels under the skin where you had treatment. These are spider veins, or ‘telangiectasia’ and are permanent. They may appear months to years after treatment.

Cough or shortness of breath

Occasionally, radiotherapy can inflame part of the lung behind the treated area.

This causes:

• a dry cough
• shortness of breath
• a low-grade fever.

When to contact your doctor

Contact your treating team if you experience any ongoing shortness of breath or cough, especially in the month after you finish radiotherapy.

Prevention/treatment

This usually heals by itself over time. If the side effect makes you uncomfortable, your doctor may prescribe anti-inflammatory drugs, such as steroids.

Limited shoulder movement, with pain

Some stiffness in the shoulder or breast is common. Less often, radiotherapy can damage the deeper tissues of the treated area. This scars the tissues, causing pain and limited movement. You may not notice this until several weeks after you finish treatment.

When to contact your doctor

Contact your doctor if you're having difficulty doing daily tasks.

Prevention/treatment

Ask your treating team for a referral to a specialised physiotherapist. They may give you:

• massage to treat the symptoms
• a specific exercise program to relieve your symptoms.