The value of ultrasound (US)-based radiomics in predicting axillary lymph node metastasis in patients with T1 stage breast invasive ductal carcinoma with negative axillary US results.

To evaluate the potential application value of qualitative and quantitative contrast-enhanced ultrasound (CEUS) features for predicting axillary lymph node metastasis in early-stage breast cancer, with special emphasis on area ratio. 146 patients with 146 T1 stage breast cancers were subjected to conventional ultrasound (US) and CEUS before surgeries. Logistic regression analysis was used to identify the associated risk factors and a prediction model was created to predict T1 stage breast IDCs with positive of axillary lymph node metastasis (ALNM). The diagnostic performance of the prediction model was assessed by the analysis of the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy. The value of area ratio, a quantitative CEUS feature, was evaluated. Logistic regression analysis indicated that taller than wide shape on conventional US, coarse or twist penetrating vessels, and area ratio > 1.93 on CEUS were independent risk factors for IDCs with ALNM-positive (all P < 0.05). Among all risk factors, the area ratio > 1.93 showed the highest AUC (i.e. 0.818). The prediction equation was established as follows: P = 1/1 + Exp∑ [-2.665 + 1.750×(if taller than wide shape) + 1.791×(if coarse or twist penetrating vessels) + 4.372×(if area ratio > 1.93)]. In comparison with US BI-RADS alone, the AUCs of the prediction model for both readers increased significantly (AUC: 0. 919 vs. 0.677 in reader 1, 0.919 vs. 0.707 in reader 2, both P < 0.001). Conventional US and CEUS features, especially the area ratio > 1.93 on CEUS, may be useful in the noninvasive prediction of ALNM-positive in breast IDCs.