To study the value in the diagnosis of benign and malignant nodules of shear wave elastography (SWE) in the surrounding tissues of the breast.

Female patients who underwent needle biopsy or surgery for breast masses in the Fourth Affiliated Hospital, Zhejiang University School of Medicine from January 2020 to December 2020 were selected. They were performed SWE inspection and got the average (E-mean), maximum (E-max), minimum (E-min) and standard deviation (E-SD) of Young's modulus inside the mass. Then, we started the "shell" function and adjusted the "shell" value to 0.5 mm, 1 mm, and 2 mm successively to obtain E-mean, E-max, E-min and E-SD of 0.5 mm, 1 mm, 2 mm around the mass. According to the final pathology results, the four sets of data were compared and the ROC curves were drawn.

A total of 68 patients with 76 lesions were included. Pathologically, among 76 masses, there were 44 benign masses and 32 malignant masses. E-mean, E-max and E-SD of 0.5 mm, 1 mm, 2 mm around and inside the malignant mass were higher than those of benign masses. The difference was statistically significant (P＜0.05). There was no significant difference in E-min between benign and malignant tumors within and 0.5mm, 1mm, and 2mm around the tumor (P＞0.05). According to the ROC curve separately, it could be seen that the best cut-off values of E-mean, E-max and E-SD inside the tumor for diagnosing benign and malignant tumors were 35.14 kPa, 80.46 kPa, 11.67 kPa, respectively. At this time, the AUC were 0.785, 0.824, 0.801, respectively. The best cut-off values of E-mean, E-max, and E-SD in the 0.5 mm area around the mass for diagnosing benign and malignant masses were 39.44 kPa, 86.15 kPa, and 14.02 kPa, respectively. At this time, the AUC were 0.770, 0.835, 0.817, respectively. The best cut-off values of E-mean, E-max, and E-SD in the 1mm area around the tumor for diagnosing benign and malignant tumors were 41.68 kPa, 90.46 kPa, and 15.98 kPa, respectively. At this time, the AUC were 0.806, 0.886, 0.825, respectively. The best cut-off values of E-mean, E-max, and E-SD in the 2mm area around the mass for diagnosing benign and malignant masses were 44.16 kPa, 95.45 kPa, and 16.81 kPa, respectively. At this time, the AUC were 0.821, 0.926, 0.842, respectively. Combining all the data, the AUC of E-max in the 2 mm area around the mass was the largest and the diagnostic value was the highest. At this time, the sensitivity was 93.75% and the specificity was 93.18%.

The effectiveness of SWE in the diagnosis of benign and malignant nodules in the surrounding tissues of the breast is higher than that of the internal tissues. Among them, when the "shell" takes 2 mm, the diagnostic efficiency is the highest and E-max is used as the diagnostic parameter.