Enhanced pre-operative axillary staging using intradermal microbubbles and contrast-enhanced ultrasound to detect and biopsy sentinel lymph nodes in breast cancer: a potential replacement for axillary surgery.

12 Feb 2018

OBJECTIVE: To compare the experience of 4 UK Centres in the use of intradermal microbubbles and contrast enhanced ultrasound (CEUS) to pre-operatively identify and biopsy sentinel lymph nodes (SLN) in patients with breast cancer. METHODS: In all centres, breast cancer patients had a microbubble/ CEUS SLN core biopsy prior to axillary surgery and patients in Centres 1 and 2 had a normal grey-scale axillary ultrasound. Data was collected between 2010 and 2016; 1361 from Centre 1 (prospective, sequential), 376 from Centre 2 (retrospective, sequential), 122 from Centre 3 (retrospective, selected) and 48 from Centre 4 (prospective, selected). RESULTS: SLN were successfully core biopsied in 80% (Centre 1), 79.6% (Centre 2), 77.5% (Centre 3) and 88% (Centre 4). The sensitivities to identify all SLN metastases were 46.9% (95% CI 39.4-55.1), 52.5% (95% CI 39.1-65.7), 46.4% (95% CI 27.5-66.1) and 45.5% (95% CI 16.7-76.6) respectively. Specificities; 99.7% (95% CI 98.9-100), 98.1% (95% CI 94.5-99.6), 100% (95% CI 93.2-100%) and 96.3% (95% CI 81-99.9) respectively. Negative predictive values; 87.0% (95% CI 84.3-89.3), 84.5% (95% CI 78.4-89.5), 86.9% (95% CI 82.4-90.3) and 86.2% (95% CI 78.4-91.5) respectively. At Centres 1 and 2, 12/730 (1.6%) and 7/181 (4%) respectively of patients with a benign microbubble/ CEUS SLN core biopsy had 2 or more lymph node (LN) macrometastases found at the end of primary surgical treatment. CONCLUSION: The identification and biopsy of SLN using CEUS is a reproducible technique. Advances in knowledge: In the era of axillary conservation, microbubble/ CEUS SLN core biopsy has the potential to succeed surgical staging of the axilla.