Pre-operative localisation of axillary lymph nodes using radiofrequency identification (RFID) tags: a feasibility...

To evaluate the safety and feasibility of using radiofrequency identification (RFID) tags for the localisation of axillary nodes prior to targeted excision in a National Health Service (NHS) breast unit.

Retrospective data collection was carried out to analyse the first 75 cases of RFID-targeted axillary nodes inserted between 12 June 2019 and 27 October 2022, during which an overall total of 1,296 breast and axillary tags were deployed in 1,120 patients.

Of the 75 axillary tags, 70 (93%) had a primary breast cancer and five (7%) had no known breast cancer but had an abnormal node targeted for diagnostic excision. Of the 70 with breast cancer, 20 (29%) underwent neoadjuvant chemotherapy (NAC) including one neoadjuvant endocrine therapy. Localisations were performed an average of 11 days before surgery (median 6, range 1-95; n=75). Patients undergoing NAC had their tags inserted after completing treatment due to the artefact caused by the tags on magnetic resonance imaging (MRI). Tag deployment had a 100% success rate, with 62 tags (83%) lying within the node and 13 tags (17%) lying directly adjacent to the node, either in direct contact (nine of 13), or a maximum of 8 mm from the target (four of 13). All tags and their respective nodes were excised successfully at surgery with no significant complications. There were four cases of tag dislodgement during excision, but overall, this did not compromise retrieval of the tag or the node.

The use of RFID tags for the preoperative localisation of axillary nodes is safe and feasible.