Tc99m Sestamibi Molecular Breast Imaging

PRIMARY OBJECTIVE: I. To evaluate the ability of technetium Tc-99m sestamibi (Tc 99m sestamibi) molecular breast imaging (MBI) to predict early response to neoadjuvant chemotherapy (NAC) and to assess residual disease at the completion of NAC in patients with locoregional invasive breast cancer. SECONDARY OBJECTIVES: I. To evaluate and qualitatively characterize Tc 99m sestamibi uptake by tumor on MBI at the baseline, after 2 cycles of NAC and at the completion of NAC. II. To compare assessment of tumor response to NAC by MBI with digital mammography (DM), and breast ultrasound (US) exams. III. To compare tumor size and distribution observed from MBI at the completion of NAC with extent of residual disease at surgery by pathological evaluation. IV. To develop image acquisition and processing algorithm that quantifies the Tc 99m tumor uptake. EXPLORATORY OBJECTIVE: I. To determine effect of molecular subtype of cancer (Her2+, ER/PR/Her2- and ER+/Her2-) on diagnostic performance of MBI in predicting treatment response. OUTLINE: Patients undergo technetium Tc-99m sestamibi molecular breast imaging over 45 minutes at baseline (before start of NAC), after 2 courses of NAC (6-12 weeks, depending on the regimen), and the completion of NAC but before surgery. Patients also undergo breast ultrasound and mammographic imaging as standard of care at the same time points.