Evaluation of Magseed as Localization Device for Biopsy Proven Metastatic Axillary Lymph Nodes

Currently, breast cancer patients who are treated with neoadjuvant chemotherapy (NAC) before surgery may have a biopsy clip placed in the lymph node at the time of or shortly after percutaneous biopsy. Following 12-20+ weeks of NAC, pre-surgical localization of the sampled axillary lymph node using a radioactive seed can be done up to 5 days prior to surgery. Localization of the sampled lymph node in patients with complete imaging response to NAC can be technically challenging if the biopsy clip is not sonographically visible. This study is designed to see if it is feasible to place a Magseed, which is magnetic seed, into the abnormal node either at the time of fine needle aspiration (FNA) or after NAC, just prior to surgery, and to be able to accurately identify the abnormal node at the time of surgery.