Role of FDG PET-CT in evaluation of locoregional nodal disease for initial staging of breast cancer

Core Tip

Core tip: The presence and extent of locoregional nodal metastasis at diagnosis is the single most important prognostic factor in breast cancer. The predominant lymphatic drainage pathway from the breast cancer is toward the axilla. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a good predictor of axillary disease and correlates well with sentinel lymph node biopsy (SLNB). FDG PET/CT may help to identify patients with high axillary lymph node burden who could then move directly to axillary lymph node dissection (ALND) and would not require the additional step of SLNB. However, FDG PET/CT cannot replace SLNB or ALND due to unsatisfactory sensitivity secondary to the limitation of its spatial resolution. The internal mammary node (IMN) involvement is of prognostic significance in breast cancer, and IMN metastasis has been associated with higher rate of distant metastasis and lower overall survival rates. Limited preliminary data indicated that FDG PET/CT plays a role in identification of positive IMN, and it is superior to conventional imaging modalities.