Breast conserving therapy (BCT), comprised of complete surgical excision of the tumor (partial mastectomy) with post-operative radiotherapy to the remaining breast tissue, is feasible for most women undergoing treatment for breast cancer. The goal of BCT is to achieve local control of the cancer, as well as to preserve a breast that satisfies the woman's cosmetic concerns. While most women undergo partial mastectomy with satisfactory cosmetic results, in many patients the remaining breast is left with major cosmetic defects, including concave deformities, distortion of the nipple areolar complex, asymmetry and changes in tissue density characterized by excessive density associated with parenchymal scarring. There are currently no tools, other than surgical experience and judgment, which can predict the impact of partial mastectomy on the contour and deformity of the treated breast. Our long term objectives are to determine if a computational model can allow prediction of the breast contour, surface features and cosmetic outcome after partial mastectomy and potentially identify targets for intervention to improve cosmetic results. The present study includes two women with breast cancer who have elected to undergo BCT and are being treated at the Methodist Hospital in Houston, TX. Our initial studies focus on postoperative changes in the breast associated with early tissue remodeling prior to radiotherapy. Later studies will include the impact of radiotherapy and healing on surgery recovery. In this paper we have achieved the following tasks: 1. define the pattern of cosmetic defects for women undergoing BCT, 2. investigate how patterns of deformity can be predicted based on preoperative imaging and surgical data points, 3. define mathematical models predictive of changes in surface contour and deformity immediately after BCT.