HER2-positive breast cancer: 18F-FDG PET for early prediction of response to trastuzumab plus taxane-based neoadjuvant chemotherapy

Purpose To investigate the value of 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET/CT) to predict a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) in women with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Material and methods Fifty-seven consecutive women with HER2-positive breast cancer, treated with trastuzumab plus taxane-based NAC, were prospectively included. Maximum Standardized Uptake Value of the primary tumor and axillary nodes were measured at baseline (PET 1 .SUV max ) and after the first course of NAC (PET 2 .SUV max ). Tumor metabolic volumes were assessed to determine Total Lesion Glycolysis (TLG). The tumor metabolic response (ΔSUV max and ΔTLG) was calculated. Results In univariate analysis, negative hormonal receptor status ( p = 0.04), high tumor grade ( p = 0.03), and low tumor PET 2 .SUV max ( p = 0.001) were predictive of pCR. Tumor ΔSUV max correlated with pCR ( p = 0.03), provided that tumors with low metabolic activity at baseline were excluded. ΔTLG did not correlate with pCR. In multivariate analysis, tumor PET 2 .SUV max