Breast Brachytherapy Outcomes Evaluation

Margaret S. Pierce, University of Tennessee--Knoxville

Abstract

BREAST BRACHYTHERAPY OUTCOMES EVALUATION As the diagnosis of breast cancer improves a significant number of women present with stage 0 or stage 1 disease. Many of these women are candidates for breast conserving surgery followed by irradiation of the breast. Conventional post-surgical radiation therapy involves daily whole breast irradiation for 5 to 7 weeks. Data indicate that the most common site of recurrence of cancer after breast conservation and radiation is in the tumor bed. This observation has led to the development of several partial breast irradiation methodologies which deliver the largest radiation dose to the lumpectomy bed. The MammoSite™ radiation therapy system involves placement of a balloon catheter before treatment with radioactive seed placement twice daily for 5 days. Although FDA approved in 2004, there continue to be questions about both short and long-term outcomes of this therapeutic option. Initial studies evaluated disease free survival and cosmetic outcomes, finding them comparable to whole breast irradiation. Identification of variables affecting outcomes other than tumor size, cell type and grade has been limited. The purpose of this study is to identify personal, disease, and patient care variables, and their relationship to outcomes such as cosmesis, complications, and disease recurrence. The variables include age, race, BMI, breast size, co-morbidities, tumor size, grade, and location within the breast, and treatment related variables such as use of prophylactic antibiotics and site care during and after therapy. A retrospective record review of all women undergoing breast balloon brachytherapy at a midsize community based cancer center in the first year after availability of this treatment was completed. The presentation will include data from those subjects treated in the first 12 months at these two centers with at least 18 months of follow-up. This will include treatment and follow-up encounters with radiation oncology and breast surgery staff. Recommendations for patient care to reduce complications and improve outcomes will be presented.