VTIQ Technology And Conventional Ultrasonography In Diagnosis Of Metastatic Axillary Lymph Nodes In Patients With Breast Cancer

ObjectiveTo analyze the conventional ultrasonography（US）and virtual touch tissue imaging quantification（VTIQ）elastography of axillary lymph nodes（ALN）of breast cancer patients,and to explore the value of VTIQ and conventional ultrasound in diagnosis of axillary lymph nodes in breast cancer patients.MethodsAccording to the established exclusion criteria,a total of 107 axillary lymph nodes of107 patients with breast cancer were included in this study.All lymph nodes were confirmed by pathology.The maximum cortical thickness,long-to short-axis diameter（L/S）ratio,vascular pattern,the blood-flow abundance,and the resistance index（RI）of the selected lymph nodes were recorded by conventional US.The conventional US score was conducted according to the evaluation criteria in this study.Shear wave velocity（SWV）of the ALNs were obtained through VTIQ technology.The maximum,minimum and average values of the remaining SWV were recorded as SWV_max,SWV_min and SWV_mean,respectively.The results of conventional US and VTIQ were analyzed by t test.Then,using pathology as a standard,receiver operating characteristic（ROC）curves were used to determine the cut-off values of conventional US scores,SWV_max,SWV_min,and SWV_mean,and the corresponding sensitivity and specificity were obtained.Meanwhile,disjunctive and conjunctive combinations of US and VTIQ were adopted to obtain the corresponding sensitivity and specificity.Mc Nemar test was used to compare the diagnostic value of conventional US,VTIQ technology and the combination.The observation indexes(maximum cortical thickness,L/S ratio,vascular pattern,the blood-flow abundance,RI,SWV_max,SWV_min,SWV_mean)were taken as independent variab-les,with the characteristics of axillary lymph nodes as dependent variables.With the path-ologic results as the golden standards,1 was considered as metastasis reactive variables.The independent variables related to reactive were assigned as 0.Univariate and multi-variate logistic regression analysis was used to select sensitive factors affecting axillary lymph node metastasis.ResultsFifty-four lymph nodes were pathologically confirmed as metastatic and 53 lymph nodes were reactive.1.The values of conventional US,SWV_max,SWV_min,SWV_mean of metastatic ALNs were significantly higher than those of reactive ALNs.The diagnostic cut-off values were 6points,1.92m/s,1.63m/s and 1.88m/s,respectively.The area under curve of SWV_mean was greater than that of SWV_max and SWV_min,with statistically significant difference（P<0.05）.2.The sensitivity and specificity of conventional US were 70.4%and 79.2%,respectively and VTIQ were 81.5%and 92.5%.The sensitivity and specificity of VTIQ alone were slightly higher than that of conventional US,but the differences were not statistically significant（P>0.05）.3.Higher than 6 of the conventional US score and≥1.88m/s of SWV_mean were used as the metastatic diagnostic criteria separately by conventional US and VTIQ.The diagn-ostic sensitivity of the disjunctive combination was significantly higher than that of the conventional US alone（94.4%VS.70.4%,x²=10.794,P=0.001）.The diagnostic specif-icity of the conjunctive combination was significantly higher than that of the conventional ultrasound（96.2%VS.79.2%,x²=88.778,P=0.000）.4.Univariate analysis showed that the maximum cortical thickness,L/S ratio,vascular pattern,the blood-flow abundance,SWV_max,SWV_minand SWV_mean had statistical differe-nces between benign and malignant ALNs（P<0.05）.Multivariate Logistic regression anal-ysis confirmed that the maximum cortical thickness,L/S ratio,vascular pattern and SWV_mean were significantly correlated with ALN metastasis,with OR values of 12.248,8.134,9.449 and 13.108 respectively,of which SWV_mean of the biggest correlation with metastasis.The corresponding risk ranking was that SWV_mean>the maximum cortical thickness>vascular pattern>L/S.Conclusions1.The conventional US and VTIQ technology can help to diagnose of axillary lymph nodes.The combination of conventional US and VTIQ technology can effectively improve the ability of ultrasonography in the diagnosis of benign and malignant axillary lymph nodes.2.The maximum cortical thickness,L/S ratio,vascular pattern and SWV_mean were independent predictors of the benign and malignant ALNs.The risk ranking was that SWV_mean>the maximum cortical thickness>vascular pattern>L/S.