This pilot clinical trial will evaluate whether the SCOUT reflector can be used to tag abnormal lymph nodes in patients with breast cancer prior to chemotherapy for targeted removal at the time of surgery. The SCOUT localization system with the SAVI reflector is non-radioactive and completely internal so can be placed into an abnormal lymph node prior to chemotherapy treatment, which theoretically will allow easier identification and therefore more reliable targeting of the abnormal lymph node for surgical removal.

PRIMARY OBJECTIVES:

I. Percentage of patients with successful retrieval of the reflector confirmed by specimen radiography.

II. Percentage of patients with successful retrieval of the biopsied node, confirmed by presence of clip, biopsy changes or treatment-related changes on pathology.

SECONDARY OBJECTIVES:

I. Total number of lymph nodes removed. II. Percentage of patients in which clipped node was a sentinel node. III. Percentage of patients with nodal pathologic complete response (PCR). IV. Residual cancer burden (RCB) score for patients with residual nodal disease.

V. Percentage of patients requiring axillary dissection. VI. Days prior to surgery of reflector insertion.

OUTLINE:

Patients undergo image-guided placement of the SCOUT reflector prior to course 2 of standard of care neoadjuvant chemotherapy. Patients undergo standard of care surgery approximately 4-8 weeks after chemotherapy completion.

Inclusion Criteria:

• Able to give written informed consent to participate in the study
• Patients with a breast cancer diagnosis of any subtype and a biopsy-proven positive axillary lymph node who will be treated first with chemotherapy
• Enlarged lymph node and/or clip targetable with image guidance
• Patients who are eligible for surgical resection of the primary breast cancer and targeted dissection of the axilla

Exclusion Criteria:

• More than 3 positive axillary nodes on imaging or matted nodes on clinical exam
• Stage IV breast cancer
• Pregnant or lactating females
• Patients with inflammatory breast cancer
• Patients with allergies to isosulfan blue or technetium, which would preclude sentinel node mapping
• Patients who have had previous axillary surgery, including sentinel lymph node biopsy