Ultrasound Monitoring of Clipped Lymph Nodes to Predict Axillary Response After Chemotherapy in Breast Cancer

This study aims to evaluate whether longitudinal multimodal ultrasound can accurately predict axillary pathological response in breast cancer patients who receive neoadjuvant chemotherapy. In this study, patients with biopsy-proven metastatic axillary lymph nodes will have a metallic clip placed in the positive node before chemotherapy. During and after treatment, the clipped lymph node will be monitored by ultrasound, including gray-scale imaging, shear wave elastography, and contrast-enhanced ultrasound. The changes in the morphological and functional features of the clipped node will be analyzed to establish a predictive model for axillary pathological complete response. The results are expected to help identify patients who may safely avoid unnecessary axillary lymph node dissection and improve individualized surgical decision-making.