Application of Targeted Axillary Lymph Node Resection in Axillary Surgery After Neoadjuvant Chemotherapy for Breast Cancer: an Open-label, Multicenter Study

Before primary systemic therapy, a core needle biopsy or fine-needle aspiration of the most suspicious axillary lymph node was performed.22 Sterile black carbon suspension (0.5 mL: 25 mg, Chongqing LUMMY Pharmaceutical Co) was injected in the cortex of the metastatic node under ultrasound guidance using a 25G needle by a trained ultrasonographer at the time of biopsy or during a separate session. The injection volume was recorded and varied depending on node size and operator. The trained ultrasonographer had more than 5 years of puncture experience. Of note, for the patients with multiple abnormal nodes or N3 disease under ultrasound at diagnosis, only the pathologically-proven lymph node is marked with carbon suspension.