For women diagnosed with early stage breast cancer, lumpectomy followed by radiation is a common treatment option. Radiation treatment is typically delivered to the whole breast, five times per week, for anywhere from 3 to 8 weeks. The radiation helps kill any cancer cells that may have been left over following the surgery but causes skin burns. Many studies have demonstrated that radiation to the whole breast is not necessary, that it can be delivered to a portion of the breast where the cancer is more likely to recur. A technique called a Permanent Breast Seed Implant (PBSI) involving the implantation of radioactive seeds has been developed to deliver the radiation to a portion of the breast. The procedure is performed on an out-patient basis under local anesthesia and light sedation. Because the radioactive seeds are permanently implanted in the breast, the patient is able to live a normal life while the seeds deliver the prescribed radiation to the breast. Previous studies on PBSI demonstrate that it is a safe and effective alternative form of radiation for appropriately selected patients after lumpectomy. However, those results have been obtained mainly from a single institution, with only 4 patients treated in another center. Further research is still needed to evaluate its safety in a multi-center setting. The purpose of this study is to ensure the appropriate training of clinicians who will be performing this procedure and to capture long term outcomes and rare complications if any.