Enhancing SLN metastasis diagnosis in breast cancer: A comparative study of percutaneous and intravenous CEUS with FNA.

[BACKGROUND] This study aimed to evaluate the diagnostic efficacy of various observation indicators from Percutaneous Contrast-Enhanced Ultrasound (P-CEUS) and Intravenous Contrast-Enhanced Ultrasound (IV-CEUS) for sentinel lymph nodes (SLNs) in breast cancer patients, and to further explore the diagnostic value of Contrast-Enhanced Ultrasonography-guided Fine-Needle Aspiration Cytology (CEUS-FNAC) for SLN metastasis.

[METHODS] A retrospective analysis was conducted on 172 breast cancer patients who underwent planned sentinel lymph node biopsy in the department of breast surgery from April 2020 to May 2023. All patients underwent preoperative P-CEUS and IV-CEUS examinations, followed by FNAC of the SLNs. The results were compared with the pathological gold standard.

[RESULTS] Among the 172 breast cancer patients, uniform distribution of contrast and slow washout on P-CEUS were good indicators for non-metastatic SLNs. Uniform distribution and no volume increase compared to the 2D baseline on IV-CEUS were good indicators for non-metastatic SLNs. Multivariate analysis showed that the post-contrast distribution pattern on P-CEUS and post-contrast volume increase on IV-CEUS were good independent predictors, with the former having better diagnostic efficacy than the latter. Preoperative CEUS-FNAC for localization and characterization has the potential to reduce the false-negative rate associated with traditional SLN biopsy surgery.

[CONCLUSION] P-CEUS and IV-CEUS have clinical application value for the identification and localization of sentinel lymph nodes in breast cancer patients. CEUS-guided FNAC demonstrates high clinical diagnostic efficacy for suspicious metastatic axillary lymph nodes and can serve as a reliable minimally invasive assessment and risk stratification tool prior to surgery.