Application Value Of Preoperative Contrast-enhanced Ultrasound In Clinical Diagnosis Of Sentinel Lymph Nodes In Breast Cancer

Objective:The conventional ultrasound and contrast-enhanced ultrasound examination in breast cancer patients before operation are used to assess whether the sentinel lymph node has metastasis or not.With the pathological results as the gold standard,the accuracy,sensitivity and specificity of the conventional ultrasound and contrast-enhanced ultrasound are compared to preliminarily explore the application value of preoperative contrast-enhanced ultrasound in the clinical diagnosis of sentinel lymph node in breast cancer.Methods:A total of 111 patients who were admitted to the Department of Breast Surgery,Affiliated Hospital of Guizhou Medical University from May 2020 to December 2021 for the treatment of early breast cancer were selected.First,the nature of axillary lymph nodes was preliminarily judged by conventional ultrasound,and then the sentinel lymph nodes were examined by contrast-enhanced ultrasound to observe the contrast-enhanced ultrasound characteristics of the lymph nodes,so as to determine whether the lymph nodes had metastasis.Sentinel lymph node biopsy was performed using indocyanine green fluorescence imaging combined with methylene blue staining.Using pathological results as the gold standard,the sensitivity,specificity,accuracy,positive predictive value and negative predictive value of conventional ultrasound and contrast-enhanced ultrasound in the preoperative diagnosis of sentinel lymph node metastasis were compared.Besides,receiver operating characteristic(ROC)curve was also drawn to calculate the area under the curve(AUC).The factors affecting the diagnosis of sentinel lymph node metastasis by contrast-enhanced ultrasound were analyzed based on the characteristics of clinical data such as the patient’s age,BMI,menopause,tumor size,tumor stage,molecular typing,tumor location,and pathological type.Results:Sentinel lymph nodes were detected by contrast-enhanced ultrasound in 109 of111 patients,with the detection rate of 98.21%.Conventional ultrasound was used to predict the positive axillary lymph nodes in 30 cases and the negative in 79 cases.Contrast-enhanced ultrasound showed SLN positive in 27 cases and SLN negative in82 cases.Pathological results showed that SLN was positive in 27 cases and negative in 82 cases.Among 109 patients,the sensitivity,specificity and accuracy of conventional ultrasound in the evaluation of axillary lymph nodes were 51.9%,80.5%and 73.4%,respectively.The positive predictive value and negative predictive value were 46.7% and 83.5%,respectively.The cutoff value and AUC were 0.323 and0.662(95% CI 0.565–0.750),respectively.The Kappa value for consistency test with pathological results was 0.312.The sensitivity,specificity and accuracy of contrast-enhanced ultrasound were 85.2%,95.1% and 92.7%,respectively.The positive predictive value and negative predictive value were 85.2% and 95.1%,respectively.The cutoff value was 0.803 and AUC was 0.902(95% CI 0.830–0.950).The Kappa value for consistency test with pathological results was 0.803.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of contrast-enhanced ultrasound were higher than those of conventional ultrasound(P < 0.05),and the difference was statistically significant.The sentinel lymph node detection by contrast-enhanced ultrasound had no significant relationship with the age,BMI,menopause or not,tumor size,tumor stage,molecular type,tumor size,tumor location and pathological type of the patient(P >0.05).Conclusions:1.For breast cancer patients with negative axillary,preoperative sensitivity,specificity,accuracy,positive predictive value and negative predictive value of contrast-enhanced ultrasound in breast cancer sentinel lymph node are significantly higher than those of conventional ultrasound.Preoperative diagnosis of breast cancer with axillary lymph node metastasis by ultrasound is better than conventional ultrasound.2.Contrast-enhanced ultrasound has no significant correlation with breast cancer patients’ age,BMI,stage,molecular typing,tumor location and pathological type.It proves that the effectiveness of contrast-enhanced ultrasound in sentinel lymph node detection is not affected by the above clinical pathological parameter s,and is highly applicable in clinical practice.