Definition
Accelerated partial breast irradiation (APBI), also referred to as high dose rate breast brachytherapy, is a shortened course of high dose radiation therapy that is given to breast cancer patients and targets the area of the breast where the cancer is most likely to recur.
Purpose
One of the purposes of APBI is to reduce the radiation treatment time from seven or eight weeks, which is generally required with conventional whole breast irradiation, to four or five days. Planning for seven or eight weeks of radiation treatment is difficult for many women, especially women who work outside the home, are single parents, and/or live in rural areas. Reducing the treatment time to one week is not only more convenient for many patients, but it also helps them with emotional closure. In other words, the sooner they are done with the treatments, the sooner they can put the cancer behind them.
Another purpose of APBI is to save the breast while still preventing a recurrence of the cancer. In fact, Robert R. Kuske, M.D., a radiation oncologist who has led several clinical trials investigating high dose rate breast brachytherapy, is quick to point out that nearly "80% of women diagnosed with breast cancer are candidates for breast conservation therapy, in which the lump is surgically removed and any remaining cancerous cells are destroyed by radiation therapy, leaving the breast intact." Nonetheless, nearly 45% of the women that qualify for breast conservation therapy choose to have a mastectomy anyway, despite the fact that twenty years of research validates that there is no difference in the survival rates of women that choose to have a mastectomy rather than a lumpectomy followed by radiation therapy. Dr. Kuske believes that the patients who could choose to save their breasts opt for a mastectomy because they are not only unable to face the inconvenience of many weeks of external beam radiation therapy, but they also fear the effects of whole breast irradiation on their uninvolved breast, skin, ribs, lung, and heart. Therefore, patients with these concerns may find APBI a more favorable option, given that the treatment time is shorter and, due to the way the treatment is delivered, "less radiation will reach the skin, lungs, heart, ribs, the healthy part of the breast, and the body as a whole," as explained by the Cancer Treatment Centers of America.
A wealth of cancer specialists recommend that a certain criteria be considered when breast cancer patients are selected for APBI rather than whole breast irradiation. It is generally agreed that the patient should be older than forty-five years of age; the American Society of Breast Surgeons prefers, in fact, that the patient be older than fifty years of age. The extent of lymph node involvement must be considered and the patient should have "negative microscopic surgical margins of at least 2 mm in all directions," according to the American Society of Breast Surgeons. Opinions vary regarding tumor size. For example, the experts at the Cancer Treatment Centers of America believe that the tumor should be 4 cm or less in size. Others, such as the American Society of Breast Surgeons, take a more conservative view and believe that only patients with tumors 2 cm or less should be considered for the treatment.
Description
High Dose Rate Breast Brachytherapy
There are two ways to accomplish the administration of APBI, both of which can be done on an outpatient basis. One way, called high does rate breast brachytherapy, involves inserting multiple plastic tubes, referred to as catheters, in the breast area surrounding the lumpectomy cavity. A tiny radioactive seed, which delivers the correct amount of radiation, is inserted in the catheters. Generally, the treatment is given twice a day for five days, although some treatment regimes vary according to the individual needs of the patient. Treatment sessions usually take no longer than 20 minutes. At the end of the five-day treatment, the catheters are removed.
Some patients experience minor discomfort due to the insertion and removal of the catheters, whereas others do not. Because the treatment is more invasive than external beam radiation therapy, patients should talk with their physicians regarding what pain, if any, they might experience. For the most part, however, patients are able to return to their daily routine after each treatment.
Mammosite Breast Brachytherapy
Another way to administer APBI is called mammosite breast brachytherapy, which is also known as balloon catheter brachytherapy. In this case, a small balloon is attached to a single catheter, which is inserted into the lumpectomy cavity. Then the balloon is inflated and a computer-controlled machine places the high dose radioactive seed inside the balloon. The experts at the Cancer Treatment Centers of America point out that, "some women interested in this treatment are finding out that they do not qualify because of breast shape or because they so not have a fluid filled cavity remaining in their breast after a lumpectomy." Fortunately, this does not disqualify them from the other method of administering APBI.
The radioactive seeds are removed after each appointment; therefore, patients will not be rendered radioactive between their appointments or after their final appointment. Both types of brachytherapy are covered under most insurance plans.
Aftercare
Many patients report redness, bruising, and breast pain, such as soreness. Some minor scarring can be expected as well.
Risks
As with any surgical procedure, there are risks. Patients should talk to their doctors regarding their individual risk factors.
Questions to Ask Your Doctor
- How often have you performed this procedure?
- How painful is it to have the catheters inserted and removed?
- What do I need to do to avoid infection?
- Can I expect any numbness or nerve damage from the treatment?
- Do many of your patients express regret over choosing APBI over external beam radiation therapy?
Treatment Outcomes
More clinical studies need to be conducted to support the data currently available regarding APBI treatment outcomes. Until that time, Douglas Arthur, M.D., suggests that "it appears appropriate for those offering APBI to adhere to the conservative principles outlined in the reports available from the American Brachytherapy Society and the American Society of Breast Surgeons."
Resources
Books
Hirshaut, Y., Pressman, P. I. Breast Cancer: The Complete Guide. 4th ed. New York, NY: Bantam Books, 2004.
Periodicals
Arthur, D. "Accelerated partial breast irradiation: a change in treatment paradigm for early stage breast cancer." Journal of Surgical Oncology 84 (2003): 185–191.
Bankhead, C.. "Accelerated partial breast irradiation: more data needed, researchers say." Journal of the National Cancer Institute 95 (2003): 259–261.
Other
"Breast Brachytherapy." Cancer Treatment Centers of America [cited 1 April 2005].
Cancer Weekly "Brachytherapy Saves Breast, Decreases Treatment Time." Cancer Weekly August 2004 Cancer Weekly. 1 April 2005
"HDR Breast Brachytherapy Treatment for Breast Cancer." Frank. C. Love Cancer Institute at St. Anthony [cited 1 April 2005].
Jackson, J., Guggolz, R. "Brachytherapy Frequently Asked Questions." American Brachytherapy Society 2002 American Brachytherapy Society. 1 April 2005
"Partial Breast Irradiation." MammoSite [cited 1 April 2005].
The American Society of Breast Surgeons "Consensus Statement for Accelerated Partial Breast Irradiation." The American Society of Breast Surgeons April 2003 The American Society of Breast Surgeons. 1 April 2005
—Lee Ann Paradise
