Scientific Session 08 — Breast - UltrasoundTuesday, May 2, 2017
2580. The Role of Contrast-Enhanced Ultrasound in Assessing the Axilla in Patients With Breast Cancer
Sharma N*, Haigh I. Leeds Teaching Hospital National Health Service Trust, Leeds, United Kingdom
Address correspondence to N. Sharma (email@example.com)
Objective: The Z0011 trial showed that patients with two nodes positive at sentinel lymph node biopsy (SLNB) treated with no further surgery had a low recurrence rate comparable with the rate in patients who were treated with further axillary surgery. The literature has shown that women with positive nodes on ultrasound (US) are a different population to those positive at SLNB and should therefore not be treated similarly. The limitation with axillary US is the inability to identify the sentinel lymph node with certainty, but as techniques have advanced, contrast-enhanced US (CEUS) of the axilla allows us to visualize the sentinel node. This prospective study looks at the utility of CEUS in women with normal or abnormal axillary US findings with benign biopsy results.
Materials and Methods: From June 2013 to June 2016, women diagnosed with breast cancer with negative axillary US findings or benign axillary biopsy who were considered suitable were referred for CEUS of the axilla. The axillary US findings, biopsy results, and final surgical histology were recorded. The size of tumor deposit was measured by the pathologist as individual tumor cells, micrometastases (0.2 to < 2.0 mm), and macrometastases (= 2 mm).
Results: A total of 131 patients were identified (130 women, 1 man). In 13 cases (10%), CEUS failed to identify the sentinel node. In 118 patients, the sentinel lymph node was visualized. Definitive results of B2 (85 patients) or B5b (19 patients) were made in 104 cases (80%), and a B1 or C1 result was obtained in 14 cases. Of the B1 or C1 results, four patients had malignant nodes at SLNB (individual tumor cells, n = 1), one positive node (n = 2), and two positive nodes (n = 1). Of the B2 results, 16 were false-negative, with eight cases being micrometastases or individual tumor cells. Of the remaining eight cases, four had one positive node, two had two positive nodes, and three had three or more positive nodes. Twenty cases had false-negative results, but only two had three or more nodes. Of the 19 cases that were B5b, 11 had two or fewer positive nodes and eight had three or more positive nodes.
Conclusion: CEUS has a role to play in identifying significant nodal burden within the axilla in patients with normal gray-scale US or benign biopsy. The advantage of CEUS over gray-scale US is the ability to identify the sentinel node under US. If individual tumor cells and micrometastases are excluded, CEUS has a negative predictive value of 91% (8/85 patients). Patients with positive nodes on CEUS had a higher nodal burden compared with those who had false-negative results after B2 biopsy. CEUS is an effective method to help identify patients who should be managed with SLNB and those who require axillary surgery due to biopsy-proven malignant sentinel nodes at axillary US.