Value of an expanded range of lesions on contrast-enhanced ultrasound for the diagnosis of hypervascular breast masses

BACKGROUND: Breast cancer lesions show an expanded range on contrast-enhanced ultrasound (CEUS). Here, we quantitatively analyze this index to explore its effective cutoff value for distinguishing benign and malignant lesions and the corresponding diagnostic performance and investigate its role in prognostic assessment of malignant lesions. METHODS: Consecutive patients who underwent CEUS for breast lesions during the period from September 2017 to June 2019 were included. Original CEUS images were selected, displayed in dual-frame mode, and measured when enhancement of the lesion reached its peak. The longitudinal diameter, transverse diameter, and area of the lesion on the two-dimensional images and the corresponding postenhancement images were measured to calculate six indicators: longitudinal diameter increment, transverse diameter increment, area increment, percent increase in longitudinal diameter, percent increase in transverse diameter, and percent increase in area increment. With postoperative pathology as the gold standard, the cutoff values for distinguishing benign and malignant lesions and the correlations of these indicators with pathological subtypes and pathological grades were evaluated. RESULTS: Malignant lesions showed a more significantly expanded range after enhancement compared to benign lesions, especially in terms of area increase. When the cutoff value of the area increment was set at 0.47 cm(2) for distinguishing between benign and malignant lesions, the area under the curve (AUC) was 0.945, and the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 90.1%, 91.5%, 90.9%, 87.2%, and 93.5%, respectively. The pathologically measured maximum diameter of malignant masses correlated with the percent increase in transverse diameter, area increment, and percent increase in area increment. The longitudinal diameter increment in the luminal A group was significantly smaller than that in the human epidermal growth factor receptor 2 (HER2)+ group. The percent increase in transverse diameter was helpful for predicting the pathological grade of malignant masses. When the cutoff value of the percent increase in transverse diameter was set at 10.84% for pathological grading, the AUC was 0.623, and the sensitivity was 90.8%. CONCLUSIONS: Indicators related to the expanded lesion range on CEUS are helpful in differential diagnosis of benign and malignant lesions and in prognostic assessment of pathological grades.