Background: The accuracy of sentinel lymph node biopsy (SLNB) after neoadjuvant therapy (NAT) has been improved with the placement of a clip in the positive node prior to treatment. Several methods have been described for clipped node excision during SLNB after NAT. We assessed the feasibility of intraoperative ultrasound (IOUS)-guided excision of the clipped node during SLNB and investigated whether the accuracy of SLNB is improved.
Methods: After approval by the Institutional Ethics Committee, all breast cancer patients undergoing NAT had an US-visible clip placed in the positive node. The ILINA trial consisted of IOUS-guided excision of the clipped node along with SLNB and axillary lymph node dissection (ALND).
Results: Forty-six patients had a clip placed in the positive node. In two (4.3%) cases, the clip could not be seen prior to surgery and the patient underwent ALND; however, the clipped node was successfully removed by IOUS-guided excision in 44 patients. Thirty-five patients (79.5%) underwent SLNB along with IOUS-guided excision of the clipped node and ALND, and were subsequently included in the ILINA trial. Nine patients were not included (five patients with SLNB only and four patients with ALND without SLNB). SLNB matched the clipped node in 27 (77%) patients. The false negative rate for the ILINA protocol was 4.1% (95% confidence interval 0.1-21.1%).
Conclusions: IOUS-guided excision of the axillary clipped node after NAT was feasible, safe, and successful in 100% of cases. The ILINA trial is accurate in predicting axillary nodal status after NAT.