Radiation therapy for breast cancer

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

Radiation therapy is recommended:

• after breast-conserving surgery to help destroy any undetected cancer cells that may be in the breast and to reduce the risk of the cancer coming back
• sometimes after a mastectomy, depending on the risk of the cancer coming back in the chest area
• if lymph nodes from under the arm were removed and the risk of the cancer coming back in this area is considered to be high.

You will usually start radiation therapy about four weeks after surgery. If you’re having chemotherapy after surgery, radiation therapy will begin about four weeks after chemotherapy has finished.

Learn more about:

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

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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 marks will be put on your skin so the radiation therapists treat the same area each time. These marks are 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. In some cases, you may have a larger dose each day for about three weeks. Usually you can 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 therapists 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 the treatment is given.

Side effects of radiation therapy

Radiation therapy may cause the following side effects:

Tiredness – You may feel tired or fatigued (lacking energy for day-to-day activities) 1–2 weeks after radiation therapy starts, and during treatment. This usually eases a few weeks after treatment finishes.

Red and dry skin – The skin at the treatment site may become red and dry after a few weeks of treatment. It usually returns to normal 4–6 weeks after treatment ends. The nurses will show you how to care for your skin. Sorbolene cream applied twice a day can be helpful.

Inflammation and blistering – Less commonly, your skin may become itchy and/or very irritated. This will be closely monitored by the treatment team, who will recommend creams to apply to the area.

Aches – You may feel minor aches or shooting pains that last for a few moments during treatment.

Swelling – Some people develop fluid in the breast (breast oedema) that can last for up to 12 months or, in some cases, up to five years. Radiation therapy to the armpit may increase the chance of developing lymphoedema in the arm. Talk to your radiation oncologist or radiation oncology nurse about any changes you experience.

Radiation therapy to the breast does not cause you to lose hair from your head, although you may lose hair from the treated armpit. The radiation does not stay in your body during or after treatment, so it is safe for you to spend time with family and friends.

For more on this, see Radiation Therapy.

Video: What is radiation therapy?