Radiotherapy

What is radiotherapy?

Radiotherapy is the use of carefully measured and controlled high energy x-rays to destroy cancer cells. Treatment is given regularly over a period of time to have the greatest effect on the cancer cells while limiting the damage to normal cells.

Radiotherapy is used to treat breast cancer in a number of ways.

• After surgery to get rid of any remaining cancer cells left behind in the breast area - this reduces the risk of the cancer coming back. If you have had breast conserving surgery (such as a wide local excision or lumpectomy) you’ll usually have radiotherapy to the remaining breast tissue. If you have a mastectomy, you may be given radiotherapy to the chest area, particularly if the cancer is large, if there is a high risk that cancer cells may have been left behind or if cancer cells are found in the lymph nodes under the arm (axilla).
• After surgery to treat the lymph nodes above the collarbone and in the armpit - this will depend on the surgery you’ve had and whether or not the lymph nodes contained cancer cells. If all the lymph nodes have been removed, usually you will not need radiotherapy to the area under the arm.

Please note - the information below, and in this radiotherapy section, is intended for those who have been diagnosed with primary breast cancer. If you are looking for more information about secondary breast cancer and when radiotherapy may be used, please visit our page on treatments for secondary breast cancer.

When will I begin radiotherapy?

Once you have been assessed by your specialist team as being ready to receive radiotherapy, national guidance recommends that you should not have to wait more than 31 days to start your treatment. However, some people may have to wait a bit longer than this. Radiotherapy can also be delayed for medical reasons, such as waiting for a surgical wound to heal.

If you’re also going to have chemotherapy following surgery, radiotherapy is usually given towards the end of the chemotherapy treatment or, more commonly, after chemotherapy has finished.