Abstract: Objective To compare and analyze the operation time,detection rate and detection number of sentinel lymph node(SLN) who was using contrast-enhanced ultrasound(CEUS) body surface localization combined with nano carbon tracking and single dye method for sentinel lymph node biopsy(SLNB) in patients with cN0 invasive breast cancer(IBC).To explore the feasibility of CEUS body surface localization combined with nano carbon tracking for SLNB.Methods The clinicopathological data of 199 patients with cN0 IBC who were diagnosed and treated in Beijing Shunyi District Hospital from January 1st,2018 to April 30th,2023 were collected.We divided all patients into dye method group(100 cases) and combined method group(99 cases) according to SLN missing method.In dye method group,SLNB was performed with nano carbon tracer;In combined method group,SLN was marked and located by CEUS before surgery and SLNB was performed with nano carbon tracer during surgery.Results  The detection rate of SLN in this study was 96.48%(192/199).In the dye method group,the detection rate of SLN was 95.00% and the average detection number of SLN was(2.79±1.228).while in the combination method group,the detection rate was 97.98% and the average detection number of SLN was(3.32±1.469).There was no statistically significant difference in the detection rate of SLN between the two groups(P>0.05).The average detection number in combination method group was more than that in dye method group(P<0.05).However,there was no statistically significant difference in the distribution of SLN detection number between the two groups(P>0.05).The duration of SLNB surgery in the combination method group was significantly shorter than that in the dye method group[(13.83±4.58)minutes vs(19.85±3.20)minutes),P<0.05].Conclusion  Combined method for SLNB can reduce surgical time and increase the detection rate and number of SLN.

Key words: invasive breast cancer, contrast-enhanced ultrasound, sentinel lymph node biopsy, nano carbon, combined method