Radiation Therapy

Radiation therapy is a great treatment adjunct for breast cancer patients. The goal of radiation therapy is to reduce the potential for breast cancer recurrence. It reduces this risk by approximately 70%.[1]

Radiation Therapy Overview

Radiation is used often as an adjunct in breast cancer treatment as it aims to reduce the risk of breast cancer recurrence locally. It is impossible to remove every cancer cell during resection, thus radiation therapy can be used to target these cells. Surgery followed by radiation offers a great survival advantage over those who choose to have surgery alone. The risk of recurrence is 60% higher in patients that do not have radiation therapy after surgery for local control.[2]

Radiation can be used in every stage of breast cancer. In stage 0 to stage III cancer, radiation is used to prevent recurrence. In stage IV cancer, it can be used to palliate, or relieve pain when no surgical options exist.

Breast Conserving Therapy– Breast conserving therapy consists of a partial mastectomy (lumpectomy) surgery followed by radiation. This is likely to be the treatment of choice if your cancer is:[3]

  • Stage 0 to 1
  • The tumor is 4cm in diameter or smaller
  • The cancer is isolated to the tumor alone

Radiation and MastectomyEven when a mastectomy is performed removing all breast tissue, it is impossible to know if every single cancer cell has been removed. Radiation can be used to help reduce the risk of recurrence after mastectomy if:[4]

  • The tumor is >5cm
  • Cancer has spread to the axillary lymph nodes
  • The cancer has invaded the skin causing ulceration
  • The margins of the tumor after being removed are positive
  • There are >4 positive lymph nodes in the axilla

Types of Radiation

There are two types of radiation that are commonly used in healthcare, external beam radiation and internal radiation. External beam radiation is used most often in the treatment of cancer.

External Beam Radiation – External beam radiation uses a machine that generates a beam of radiation and with a linear accelerator, targets that radiation to a specific area.[5] Technology in this area of medicine has improved so much that a very small area can be targeted with minimal exposure to tissues surrounding the cancer. It is done on an outpatient basis and treatments are typically <30 minutes, five days a week for up to seven weeks.

Internal Radiation – Internal radiation is not used as often in breast cancer treatment than external beam radiation. Internal radiation uses small radioactive ‘seeds’, or ‘beads’ that are placed into a device that sits directly in the pocket of the breast where the tumor has been excised.[6] The ‘beads’ emit radiation to the area directly around it, minimizing scatter of radiation to other tissues and eliminates the need for the radiation to travel through the skin.

Intraoperative RadiationOne of the newest types of radiation therapy being used in breast cancer is intraoperative radiation. This is done in the operating room, immediately after the tumor has been removed. It takes about two minutes to complete and takes away the need for radiation treatment after surgery. Currently, this treatment is being studied for patients with early stage breast cancer with a tumor that is <2cm.[7] 

Facts About Radiation

Radiation is a type of local therapy that aims to reduce the risk of cancer recurrence in the location of the original tumor and the lymph nodes that it may have spread to.
External beam radiation does not hurt during the procedure. There may be some discomfort on the skin directly over the irradiated site.
Radiation therapy does not involve radioactive materials being left inside the body.
Internal radiation can cause some soreness at the site due to the device that is in place to deliver the radiation.
Radiation therapy for breast cancer does not make you lose your hair.
It is normal to be tired during radiation therapy, as several treatments are required for many weeks.
Side effects of radiation therapy, with the exception of minor skin changes, are temporary.
Radiation therapy is effective at reducing breast cancer recurrence by up to 60%.


1  Andrew H. Ko, M. M. (2002). Everyone’s Guide to Cancer Therapy. Kansas City: Andrews McMeel Publishing.

2  How Radiation Works. (n.d.). Retrieved from Breastcancer.org: www.breastcancer.org/treatment/radiation/how_works.jsp

3  Treatment Option Review. (n.d.). Retrieved from National Cancer Institute: www.cancer.gov/cancertopics/pdq/treatment/breast/Patient/page5

Types of Radiation. (n.d.). Retrieved from Breast Cancer: www.breastcancer.org/treatment/radiation/types

How Radiation Works, op. cit.

6 Ibid

7 Up and Coming Treatment Option for Breast Cancer: Intraoperative Radiation therapy. (2011). Women’s Health Advisor , 6.

This article was originally published on July 27,2012 and last revision and update of it was 9/2/2015.