Early FDG PET response examples. (a) Trans-axial FDG PET views show left breast lesion with baseline SUV of 4.6 and follow-up SUV of 2.5 (46% decrease). Clinical response was observed after 4 months of neoadjuvant therapy + AI. (b) Coronal FDG PET views show left axillary lymph node with baseline SUV of 4.5 and follow-up SUV of 4.5 (0% change). This patient experienced progressive disease after 7 months of AI monotherapy.