Breast MR and FACBC PET/PEM will be scheduled within one week of each other. Breast MR is a standard clinical examination and will be performed as standard.

Baseline FACBC PET/PEM will be scheduled within 1 week of beginning neoadjuvant therapy. A repeat FACBC PET/PEM will be scheduled after the conclusion of neoadjuvant therapy, and before definitive surgical management.

Accuracy of standardized uptake values will be analyzed by receiver operating characteristic (ROC) curves. ROC curves will be constructed separately for FACBC PET, FACBC PEM and MR. The area under the curve will be used as a summary measure and compared using the standard nonparametric test [20]. We will also consider dichotomizing the uptake and present accuracy using sensitivity, specificity and predictive values. Dichotomized values will be compared using the McNemar test.

Patients with locally advanced IDC or ILC, requiring neoadjuvant therapy prior to definitive surgery, will undergo FACBC PET and PEM both before chemotherapy and after. Following definitive breast surgery, pathologic specimens will be analyzed to determine if FACBC imaging can predict pathologic treatment response.