Imaging axillary lymph nodes in patients with newly diagnosed breast cancer.

The presence of axillary lymph node metastasis in patients newly diagnosed with breast cancer carries significant prognostic and management implications. As a result, there is increasing interest to stage accurately the axilla with preoperative imaging to facilitate treatment planning. Currently, the most widespread imaging techniques for the evaluation of the axilla include ultrasound and magnetic resonance imaging. In many settings, the ability to detect axillary lymph nodes containing metastases with imaging and image-guided biopsy can allow surgeons to bypass sentinel lymph node dissection and proceed with full axillary lymph node dissection. However, no imaging modality currently has sufficient negative-predictive value to obviate surgical staging of the axilla if no abnormal lymph nodes are detected. Promising advanced imaging technologies, such as diffusion-weighted imaging and magnetic resonance lymphangiography, hold the potential to improve the accuracy of axillary staging and thereby transform management of the axilla in patients newly diagnosed with breast cancer.