F-FDG PET/CT during neoadjuvant chemotherapy Running title: FDG-PET/CT for luminal breast cancer

Background: This prospective study aimed at evaluating the ability of 18 Ffluorodeoxyglucose Positron Emission Tomography/Computed Tomography ( 18 F-FDG PET/CT) to predict chemosensitivity in estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer. Methods: 64 consecutive patients underwent 18 F-FDG PET/CT scans at baseline and after the second course of neoadjuvant chemotherapy (NAC). The evolution (Δ) between the two scans of image parameters (SUVmax, SUVmean, metabolic tumor volume, and total lesion glycolysis “TLG”) was measured. Correlations between early changes of PET-derived parameters and pathological response found on surgical specimens at completion of 8 courses of NAC were estimated with Mann-Whitney-U tests. Response prediction on the basis of clinical data, histological type, or molecular markers was also assessed (Fisher’s exact test). Receiver operating characteristic (ROC) analysis was used to compare area under the curves (AUC) of the various parameters. ha l-0 07 77 90 1, v er si on 1 18 J an 2 01 3