Radiation Treatments for Breast Cancer
It was estimated that over 200,000 new cases of breast cancer would be diagnosed in the United States in 2010* Fortunately, new advances in radiation therapy and other cancer-fighting solutions are helping
to save lives each year. In this section of our website, you can learn more about radiation technology and how it's used to treat breast cancer, find out what you might experience during treatment, and read stories from breast cancer survivors.
For breast cancer, many patients are treated with a combination of surgery, chemotherapy and/or radiation therapy.
The first line of treatment for most breast cancer patients is one of two types of surgery:
- Lumpectomy—removal of the tumor only
- Mastectomy—removal of the whole breast
Talk to your oncologist and breast surgeon—he or she will help you decide the right kind of surgery for your cancer. Following surgery, radiation therapy is often used to treat any remaining cancer cells that may have been left behind or shed during surgery. Radiation beams are directed at the surgical site, or "seroma." Post-surgery radiation to the site where the tumor was removed has been shown to reduce the risk of recurrence significantly**.
Treatment Techniques for Breast Cancer
There are two broad categories of radiation therapy; both are designed to target the tumor precisely while minimizing exposure to the healthy surrounding tissue, especially the heart and lungs. In the first category, external beam radiation therapy, the radiation is usually delivered by a machine called a linear accelerator, or linac, which focuses a high-energy x-ray beam into your tumor site from outside your body. Whether you have a lumpectomy or a mastectomy as part of your treatment, external beam radiation is the most common treatment post-surgery.
IGRT, or image-guided radiation therapy, uses sophisticated computer software to analyze a series of image scans to create a detailed, three-dimensional picture of the target area and the surrounding tissues. The scans typically are produced by computed tomography (CT scan), magnetic resonance imaging (MRI), or positron emission tomography (PET scan).Image-guidance technology enables your team to view the tumor and its position in your body before and during each treatment.
IMRT, or intensity modulated radiation therapy with image-guidance, is the most commonly performed radiation treatment technique for breast cancer. This technique uses the 3-D scans of your body to guide the beams of radiation to the tumor from many different angles. At each of these angles, the intensity of the radiation is varied (modulated) and the shape changed to suit the shape of the tumor. This directs the prescribed amount of radiation to each part of the tumor, and minimizes exposure to the surrounding healthy tissue.
For breast cancer, radiation beams are projected at tangent angles in order to skim the chest wall. This allows for a maximum dose of radiation to be delivered to the seroma while minimizing exposure to the heart and lungs. Treatments are typically given up to five treatment times per week over a period of four to six weeks. Each session typically takes from 5 to 20 minutes. Talk to your oncologist about what you may expect with respect to your schedule.
APBI stands for Accelerated Partial Breast Irradiation. This is a hyperfractionated regime performed in 5-10 sessions (usually 10 appointments in 5 days). Hyperfractionation is a technique in which the total dose of radiation prescribed for treatment is divided into smaller doses, and delivered one treatment at a time until the total dose received by the tumor is equal to the total dose prescribed. With APBI, the radiation is delivered at a higher overall dose rate over a shorter period of time.
Internal Radiation Therapy - Brachytherapy
In the second treatment category, the radiation is delivered by radioactive material placed inside the body near the cancer cells—a procedure called brachytherapy, implant radiation therapy, or internal radiation therapy.
Brachytherapy (from the Greek, "brachy" meaning "close") is a less common approach, but may be appropriate for some women. Rather than shining the radiation beam from outside the body, the small radiation seeds (or sources) is placed inside the body at the treatment site. The doctor places one or more thin tubes inside the breast through a tiny incision. The radioactive substance or source (some are electronic), sometimes called a 'seed,' is loaded into the tube. The treatment session may last for a few minutes, and then the seed is removed. Upon removal, no radioactivity remains in the body. This type of therapy may be repeated every day for a week. Talk to your radiation oncologist about his or her treatment recommendation.
*According to the National Cancer Institute**(Lancet 376 (9758): 2041-2116. 2010)
