To assess the value of preoperative percutaneous contrast-enhanced ultrasound (CEUS) in the diagnosis of axillary sentinel lymph node (SLN) metastasis in breast cancer and the value of enhancement mode in diagnosing axillary lymph node burden.

Seventy-five breast cancer patients at the Breast Surgery Department of Harbin Medical University Cancer Hospital were enrolled from July 2020 to December 2021. Preoperative percutaneous CEUS was used to identify SLNs and record their enhancement pattern (divided into type Ⅰ uniform enhancement, type Ⅱ non-uniform enhancement, and type Ⅲ no enhancement). Pathological diagnosis was used as the gold standard. The value of enhancement pattern analysis in diagnosing axillary SLN metastasis and burden was then assessed by fourfold table.

The detection rate of CEUS for SLN in 75 breast cancer patients was 97.3% (73/75), and a total of 88 SLNs were detected. Among them, there are 40 type Ⅰlymph nodes, 42 type Ⅱ lymph nodes, and 6 type Ⅲ lymph nodes. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CEUS enhancement patterns in predicting SLN metastasis were 100%, 62.5%, 50%, 100%, and 72.7%, respectively. Twenty-four of 71 patients with stage T1/T2 breast cancer had sentinel lymph node metastasis, of whom 6 had high lymph node load and 18 had low lymph node load. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the enhancement patterns of CEUS in diagnosing SLN burden status were 100%, 56.9%, 60.6%, 17.6%, and 100%, respectively.

Percutaneous CEUS is effective in identifying axillary SLNs, and CEUS enhancement patterns can help predict axillary SLN metastasis and burden.