Tc99m Sestamibi Molecular Breast Imaging

This clinical trial studies technetium Tc-99m sestamibi molecular breast imaging in predicting tumor response in patients with locoregional breast cancer that has spread from where it began in the breast to surrounding normal tissue who are receiving neoadjuvant chemotherapy. Comparing results of diagnostic procedures, such as technetium Tc-99m sestamibi molecular breast imaging, done before, during, and after chemotherapy may help doctors predict a patient's response to treatment and help plan the best treatment.

Inclusion Criteria: 1. Female of 18 years and older of any race 2. Has biopsy-proven invasive breast cancer (BI-RADS 6) and scheduled for neoadjuvant chemotherapy (NAC). 3. Newly diagnosed biopsy proven locoregional invasive breast cancer at MD Anderson Cancer Center, or referred to MD Anderson for treatment after initial radiologic (mammographic, sonographic, etc.) exams at an outside institution in whom NAC is planned. 4. Patients with stage T1 or greater (T1-T4), nodal involvement (N0 - N3), without metastasis (M0) invasive breast cancer, including patients with inflammatory breast cancer. 5. Patients who agree to sign an informed consent to undergo MBI Exclusion Criteria: 1. Is under 18 years of age 2. Is pregnant (confirmed by the patient as Imaging Clinic standard of care) or nursing mother 3. Has lesions involving chest wall 4. Has known allergy to Tc99m sestamibi