A Prospective Multi-center Study: Contrast-enhanced Ultrasonography Combined With Blue Dye as Dual-tracer for Sentinel Lymph Node Biopsy After Neoadjuvant Therapy in Breast Cancer

False negative rate (FNR) in patients who has accepted neoadjuvant therapy is high. Blue dye and radioisotope as dual-tracer can decrease FNR. Several large clinical trials showed that using dual trace with blue dye and radioisotope can reduce the FNR to less than 10%. But radioisotope is still not approved in China and can cause radiocontamination. A novel dual-tracer which can decrease the FNR in patients after neoadjuvant therapy is urged to be explored. Contrast enhanced ultrasonography (CEUS) can make the lymphatic drainage path and sentinel lymph nodes visible. Retrospective studies found that CEUS can locate SLN precisely. So this clinical trial aim to evaluate FNR, detective rate and numbers of SLN by using CEUS combined with blue dye as dual-tracer in sentinel lymph node biopsy in breast cancer patients after neoadjuvant therapy and the accuracy of CEUS for the diagnosis of lymph node metastasis before and after neoadjuvant therapy.