Radiation Therapy for Breast Cancers

Breast Cancer Facts


Breast Cancer Prevalence

  • The leading cancer in women, outside of some skin cancers, is breast cancer across all ethnicities and races.1
  • The National Cancer Institute estimates that 1 in 8 American women have a chance of developing breast cancer during their lifetime. The risk was about 1 in 11 in 1975.2
  • Approximately 3 million women in the U.S. are living with breast cancer. About 2.3 million have been diagnosed with the disease and an estimated 1 million do not yet know they have the disease.2
  • Breast cancer is the leading cause of cancer death for U.S. women between the ages of 20 and 59, and the leading cause of cancer death for women worldwide.2
  • In 2008, 250,230 American women were diagnosed with breast cancer.3

Breast Cancer Risk

  • The risk of being diagnosed with breast cancer increases with age.4
  • Approximately 80 percent of all breast cancer cases occur in women 50 years and older, and approximately 5 percent of all breast cancer cases occur in women less than 40 years old.2
  • All women are at risk for breast cancer, and only 5 to 10 percent have inherited a mutation in the known breast cancer genes (BRCA1 and BRCA2).2
  • Obesity, high fat diets, excessive alcohol consumption and smoking are risk factors that put women at a greater risk for breast cancer.4

Breast Cancer Treatment


Patients diagnosed with breast cancer have four major options for treatment: surgery, radiation therapy, chemotherapy and hormone therapy.5

Surgery

  • A procedure to remove the tumor and some surrounding tissue is called a lumpectomy. Surgery to remove the part of the breast that has cancer and some normal tissue surrounding the tumor is a partial mastectomy. Both options are considered breast conserving surgeries.5
  • A total mastectomy is surgery to remove the entire breast that has cancer, but spares the lymph nodes under the arm or the muscle tissue beneath the breast. A modified mastectomy involves removing the entire breast and the lymph nodes.6
  • A radical mastectomy is a major operation that removes the entire breast, underarm lymph nodes and the chest wall muscles under the breast.6

Radiation Therapy

  • For patients who undergo a lumpectomy, radiation therapy is almost always recommended. A lumpectomy combined with radiation therapy is sometimes called breast-conservation therapy (BCT).7
  • Radiation therapy uses high energy x-rays or other types of radiation to kill cancer cells or keep cancer cells from growing. External beam radiation and brachy therapy (radiation delivered via needles, seeds, wires or catheters) are the two types of radiation therapy available to patients.5
  • Patients receiving external beam radiation usually receive treatment five days a week for eight weeks at an outpatient center. It is similar to undergoing an x-ray for several minutes.6
  • Internal radiation is injected into the breast tissue via catheters or seeds. It is sometimes given in addition to external beam radiation as an extra “boost.”6
  • Partial breast irradiation delivers radiation to a specific area centred around the tumor cavity, as opposed to whole breast radiation which delivers radiation to the entire breast because it is more targeted, physicians can often increase the dose to the area and speed up the duration of the treatment course by several weeks. This is called accelerated partial breast irradiation.6

Image-Guided Radiation Therapy (IGRT)

  • Image-Guided Radiation Therapy (IGRT) is a process using various techniques to locate the exact location prior to a radiation treatment. The process is designed to improve treatment accuracy so that treatment margins do not need to be as large.8
  • Research proves that at least 30 percent of all recurrences happen within one centimeter of the tumor cavity, and for an estimated 90 percent of the patients, the lumpectomy cavity rests within one centimeter of the lungs.(Resonant to provide statistic) – Must formulate some link such as cardiac events or sensitivy tof lung to radiation therapy., otherwise these two data points mean nothing when put together.
  • Another study proved that relying solely on the lumpectomy scar for the location to deliver radiation resulted in at least a partial miss of the cavity 50 percent of the time.9
  • The Clarity System, by Resonant Medical, is the first 3D ultrasound technology to IGRT for breast cancer. Clarity allows the radiation therapists to take a “real-time” image of the lumpectomy cavity at the time of treatment planning and then daily images with each consecutive radiation treatment.
  • Clarity provides radiation therapists with a method of daily lumpectomy monitoring that is based on visualization of the actual anatomy.
  • The Clarity System was FDA-approved for breast cancer treatment in 2004.
1 Center for Disease Control and Prevention: February 3, 2009
2 National Breast Cancer Coalition, 2008
3 2008 Cancer Facts & Figures, American Cancer Society
4 www.breastcancer.org Accessed on February 3, 2009
5 National Cancer Institute: February 6, 2009
6 American Cancer Society: February 6, 2009
7 www.breastcancer.org February 12, 2009
8 Duke University School of Medicine, Department of Radiology: February 12, 2009
9 “Electron boost field planning by clinical landmarks alone was inaccurate in 68% of cases.” Harrington KJ, Harrison M, Bayle P, et. al. Surgical clips in planning the electron boost in breast cancer