Evaluation of Novel Iron-based Lymphatic Mapping Agent, Magtrace, for Delayed Sentinel Lymph Node Biopsy (SLNB) in Ductal Carcinoma In-Situ (DCIS)

Inclusion Criteria: * Adults ≥ 18 years of age. * Patients with a core needle biopsy diagnosis consistent with ductal carcinoma in-situ (DCIS), Stage 0 breast cancer, who are planning to undergo a mastectomy. o The mastectomy can be with or without reconstruction and with or without contralateral prophylactic mastectomy. * Patients with a negative pre-operative axillary ultrasound. * For subjects of childbearing potential, a pregnancy test that has resulted as negative is required preoperatively. * Written informed consent obtained from the subject and the subject agrees to comply with all the study-related procedures. Exclusion Criteria: * Patients with contralateral invasive breast cancer requiring traditional sentinel lymph node biopsy at time of index operation or additional chemotherapy that may have been omitted for DCIS. * Any history of receiving chemotherapy * Prior ipsilateral breast cancer with treatment that included radiation, lumpectomy, chemotherapy, or sentinel lymph node biopsy. * Ipsilateral prior axillary sentinel lymph node biopsy for other malignancy (i.e., melanoma). * Patients with a history of upper extremity blood clot, lymphangitis/cellulitis, lymphedema, or those who use a pacemaker device * Patients with an allergy to iron, dextran, or any other ingredient in Magtrace. * Patients with an abnormal pre-operative axillary ultrasound. * Subjects who are confirmed to be pregnant. * History of any other disease, metabolic dysfunction, clinical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates the use of protocol therapy or that might affect the interpretation of the results of the study or that puts the subject at high risk for treatment complications, in the opinion of the treating physician. * Prisoners or subjects who are involuntarily incarcerated, or subjects who are compulsorily detained for treatment of either a psychiatric or physical illness.