Radiation therapy for breast cancer

Also known as radiotherapy, radiation therapy uses a controlled dose of radiation to kill cancer cells or damage them so they cannot grow, multiply or spread. The radiation is usually in the form of x-ray beams.

Learn more about:

• When is radiation therapy recommended?
• Planning radiation therapy
• Having radiation therapy
• Side effects of radiation therapy
• Video: What is radiation therapy?

When is radiation therapy recommended?

Radiation therapy is usually recommended:

• after breast-conserving surgery
• after a mastectomy – if pathology results suggest the risk of recurrence is high or if the cancer has spread to the lymph nodes, you may have radiation to the chest wall and lymph nodes above the collarbone
• if the sentinel node has cancer cells – you may have radiation to the armpit instead of axillary dissection.

You will usually start radiation therapy within eight weeks of surgery. If you’re having chemotherapy after surgery, radiation therapy will begin about 3–4 weeks after chemotherapy has finished. In some cases, radiation therapy may be offered after neoadjuvant chemotherapy and before surgery.

Planning radiation therapy

Treatment is carefully planned to have the greatest effect on the cancer cells and to limit damage to the surrounding healthy tissues. Planning involves several steps, which may occur over a few visits.

You will have a planning session at the radiation therapy centre. During this appointment, you will have a CT scan to pinpoint the area to be treated, and sometimes marks are put on your skin so the radiation therapists treat the exact same area each time. These marks are usually small dots (tattoos), and they may be temporary or permanent. Talk to your radiation therapists if you are worried about these tattoos.

Having radiation therapy

You will probably have radiation therapy daily from Monday to Friday for 3–6 weeks. Most people have radiation therapy as an outpatient and go to the treatment centre each day.

Each radiation therapy session will be in a treatment room. Although you will get radiation for only 1–5 minutes, setting up the machine can take 10–30 minutes. You will lie on a table under the machine. The radiation therapist will leave the room and then switch on the machine, but you can talk to them through an intercom.

Radiation therapy is not painful, but you will need to lie still while it is given. If the cancer is located on the left side, the radiation therapist may ask you to take a deep breath for 20–30 seconds during the treatment. This helps to inflate the lungs and rib cage, to move them away from the radiation field and minimise damage to the heart. This technique is known as deep inspiration breath hold.

If you are having radiation therapy in a private centre, the cost is not usually covered by private health insurance, so you may have to pay a gap fee. Speak to your treatment team about whether you can have treatment in a public hospital if you are worried about the cost.

Side effects of radiation therapy

Radiation therapy may cause the following side effects:

Red and dry skin  

Most people have some redness around the treated area. The skin may become dry and itchy, look sunburnt, blister, or become moist and weepy. It usually returns to normal 4–6 weeks after radiation therapy ends. The nurses will show you how to care for your skin. Ask them which moisturiser would be most helpful for you.

Skin problems

Sometimes skin may become very irritated or peel (radiation dermatitis). The treatment team will monitor your skin, and you may need dressings, or special creams or gels, to help the area heal.

Tiredness

You may start to feel tired or lack energy for day-to-day activities 1–2 weeks after radiation therapy begins. Fatigue usually gets better a few weeks after treatment finishes.

Aches

You may feel minor aches, twinges or shooting pain in the breast area during or after treatment. It should ease and become less frequent.

Swelling

Some people have swelling or fluid (breast oedema) that can last for up to a year or longer. Radiation therapy to the armpit increases the risk of swelling in the arm (lymphoedema).

Hair loss

Radiation therapy to the breast won’t make you lose the hair on your head, but you will usually lose hair from the treated armpit.

Other side effects

These are called late effects and can develop months or years after radiation therapy. Part of the lung behind the treatment area may become inflamed, causing a dry cough or shortness of breath. There is a slight risk of heart problems, but this usually happens only if you have treatment to your left breast or if you smoke. Hardening of tissues (fibrosis) may happen months or years after treatment. In rare cases, radiation therapy may cause a second cancer.

For more on this, see our general section on Radiation therapy.

→ READ MORE: Chemotherapy for breast cancer

Video: What is radiation therapy?

Watch this short video to learn more about radiation therapy.