- Home
- Breast cancer
- Treatment
- Radiation therapy
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 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 is affected – 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 three to four weeks after chemotherapy has finished. In some circumstances, radiotherapy 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 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. 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 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.
Side effects of radiation therapy
Radiation therapy may cause the following side effects:
Tiredness
You may start to feel tired or lack energy for day-to-day activities 1–2 weeks after radiation therapy begins. Fatigue usually eases a few weeks after treatment finishes.
Red and dry skin
The skin at the treatment area may become dry and itchy. Your skin may look red or sunburnt 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.
Skin problems
Less commonly, your skin may peel or become very irritated. The treatment team will closely monitor your skin, and you may need dressings or creams to help the area heal.
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 (oedema) that can last for up to 12 months or, in some cases, longer. 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.
Hair loss
Radiation therapy to the breast may cause you to lose hair from the treated armpit but doesn’t cause you to lose head hair.
Other side effects
Other side effects can develop months or years after radiation therapy. These are called late effects.
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 radiation therapy causing heart problems, but this usually happens only if you have treatment to your left breast or you smoke. In rare cases, radiation therapy may cause a second cancer.
For more on this, see our general section on Radiation therapy.
If you live in a regional or rural area, you may need to travel for radiation therapy. Patient assisted travel schemes (PATS) may help with the cost of travel and accommodation. For details, talk to the hospital social worker or call Cancer Council 13 11 20.
Video: What is radiation therapy?
Listen to our podcasts on Making Treatment Decisions and Coping with a Cancer Diagnosis
Additional resources
Prof Bruce Mann, Professor of Surgery, The University of Melbourne, and Director, Breast Tumour Stream, Victorian Comprehensive Cancer Centre, VIC; Dr Marie Burke, Radiation Oncologist, and Medical Director GenesisCare Oncology, QLD; Dr Susan Fraser, Breast Physician, Cairns Hospital and Marlin Coast Surgery Cairns, QLD; Ruth Groom, Consumer; Julie McGirr, 13 11 20 Consultant, Cancer Council Victoria; A/Prof Catriona McNeil, Medical Oncologist, Chris O’Brien Lifehouse, NSW; Dr Roya Merie, Staff Specialist, Radiation Oncology, Liverpool Cancer Therapy Centre, Liverpool Hospital, NSW; Dr Eva Nagy, Oncoplastic Breast Surgeon, Sydney Oncoplastic Surgery, NSW; Gay Refeld, Clinical Nurse Consultant – Breast Care, St John of God Subiaco Hospital, WA; Genny Springham, Consumer.
View the Cancer Council NSW editorial policy.
View all publications or call 13 11 20 for free printed copies.
Need to talk?
Support services
Coping with cancer?
Speak to a health professional or someone who has been there, or find a support group or forum
Need legal and financial assistance?
Pro bono services, financial and legal assistance, and no interest loans
Cancer information
What is radiation therapy?
Key questions about radiation therapy as part of cancer treatment
Making cancer treatment decisions
Decision-making steps, consent and second opinions