Preoperative sentinel lymph node identification, biopsy and localisation using contrast enhanced ultrasound (CEUS) in patients with breast cancer: a systematic review and meta-analysis

Aim To evaluate whether contrast-enhanced ultrasound (CEUS)-guided core biopsy of the sentinel lymph node (SLN) could identify metastatic nodes preoperatively and reduce the number of surgical SLN biopsies in patients with breast cancer and normal axillary B-mode ultrasound; and to establish whether CEUS SLN identification and localisation is a viable alternative to standard lymphatic mapping using isotope and blue dye. Materials and methods A search of several electronic databases was performed and identified studies were assessed using QUADAS-2 for methodological quality. Pooled estimates of sensitivity and specificity for identification of nodal metastases were calculated. Results Eleven prospective studies and one retrospective study with 1,520 participants were included. The SLN identification and localisation rate for CEUS-guided skin marking was 70–100%, CEUS guided-wire localisation was 89–97%, and CEUS-guided iodine-125 ( 125 I) seed localisation was 60%. Across the four studies that evaluated preoperative CEUS-guided SLN biopsy, pooled sensitivity for identification of nodal metastases was 54% (95% confidence interval [CI]: 47–61) and pooled specificity 100% (95% CI: 99–100). Conclusion CEUS is a promising technique for preoperative staging of the axilla. CEUS-guided core biopsy has the potential to identify nodal metastases in over half (54%) of patients with normal axillary B-mode ultrasound. CEUS-guided identification and localisation of the SLN may offer a viable alternative to standard lymphatic mapping using isotope and blue dye; however, further prospective studies with larger samples are warranted.