As more and more women are getting regular mammograms and are performing breast self-exams, cancers are being detected in earlier stages. This allows the surgeon to more often treat the woman with a breast-conserving lumpectomy, rather than mastectomy (breast removal). The goal of lumpectomy is to remove the cancer with a rim of normal breast tissue, and to preserve the cosmetic appearance of the breast as much as possible. If lumpectomy alone is performed, however, there can be a very high risk for recurrence of the cancer in the same breast, known as a local recurrence. The addition of radiation therapy to the lumpectomy reduces the risk of local recurrence significantly.
Radiation therapy has been used for many years to treat many different types of cancers, and it works by destroying the DNA in rapidly dividing cells. In years past, radiation therapy also did a significant amount of damage to normal cells and structures. As we have learned more about appropriate dosages for the treatment, and as the technology has improved to allow for more focused treatment specifically to the area of concern, the side effects and damage to surrounding structures is minimized.
In treating the woman with breast cancer, traditional radiation therapy is given over the course of about 6 weeks following lumpectomy – usually treatment is given 5 days a week. While the treatments are painless, there is a potential for skin discoloration and thickening, an increase in scarring, and moderate fatigue. In addition, many women find the requirement for 6 weeks of daily treatment inconvenient, especially if they must travel a distance for the treatments. As many women with early-stage breast cancer are otherwise healthy, they are often working full-time, taking care of their families, and trying to live their normal lives – 6 weeks of daily therapy can cause a significant disruption.
Partial breast irradiation is a technique in which high-dose, focused radiation therapy is delivered to the lumpectomy site, using one of several available catheter devices. The principle of the treatment is that instead of the radiation being delivered through the skin into the breast tissue, the radiation is delivered directly into the tissue of the breast. This is known as brachytherapy, and is also commonly used in treating prostate and other cancers. An advantage of partial breast irradiation is that the treatment is completed in 5 days – usually two treatments per day are given. Because the radiation therapy is delivered directly into the breast tissue, and not through the skin, higher doses are able to be given with each treatment, shortening the total treatment time.
Most often, the treatment catheter is placed after surgery, once the final pathology results are known. The catheter is placed in the office under local anesthesia, and then treatment usually begins 1-5 days later. Once treatment is complete, the device is removed in the office – no return to the operating room is needed. I have been using partial breast irradiation in selected patients since 2002, and have experience with the commercially available devices – placement of a particular device usually depends on tumor size, tumor location, and breast size. SAVI, Contura, and Mammosite are all currently available for patients who are appropriate candidates.
Use of these devices is not for every woman with breast cancer - at this time, it is recommended that partial breast irradiation be used in women with smaller, less aggressive tumors. However, data is accumulating which suggests that partial breast irradiation is as effective as standard external beam radiation therapy in terms of reducing the risk of the cancer returning. Women need to be carefully selected for this treatment, but in the appropriate patient, this is another way that we are able to treat early stage cancer in a shorter period of time and with fewer side effects.
