This is a phase 4 single-center, open-label, single-arm study evaluating the ability of 99mTc-TM to identify clipped nodes in primary breast cancer patients receiving NAC and subsequent Sentinel Lymph Node Biopsy (SLNB) as practice compared to published historical data . Sixty-four (64) patients (≥18 years) diagnosed with breast cancer and who are evaluated as having a favorable response (i.e., at least partial clinical response in the breast) to chemotherapy during the mid-treatment evaluation will be evaluated in this study. Patients will have suspicious lymph nodes assessed and one biopsied for pathological evaluation and clipped during the course of the patients' medical work-up. Patients will undergo NAC treatment and have a mid-treatment evaluation to assess response to the chemotherapy. Patients with a favorable response will complete NAC followed by identification of the clipped node and sentinel lymph nodes and standard lymph node assessment. Patients with an unfavorable response (i.e., no response to the NAC) will continue NAC but will not continue to participate in the study. All study patients undergoing SLNB will receive a single injection (0.1 ml) of 99mTc-TM (50 mcg) preoperatively. If no signal is detected within 30-60 minutes, patients may also be injected with BD (up to 10 cc), intraoperatively. Pain at injection site will be assessed pre-injection and at 1 minute after the 99mTc-TM injection.
It is anticipated that the majority of patients enrolled will receive NAC treatment. Although chemotherapy will be the primary neoadjuvant treatment used in this study, if the investigator feels the patient will benefit more from hormonal therapy, a hormonal treatment will be administered.