S. A. Morris1, D. Henry2, W. Sun2, C. Laronga2, M. C. Lee2 1University Of South Florida College Of Medicine,Tampa, FL, USA 2Moffitt Cancer Center And Research Institute,Breast Surgical Oncology,Tampa, FL, USA
Introduction: Radar reflector localization (RRL) has been identified as an effective means of guiding excision of non-palpable breast lesions compared to traditional wire localization (WL). With increasing data supporting selective or targeted axillary dissection for node positive breast cancer after neoadjuvant chemotherapy (NAC), we sought to evaluate the feasibility of RRL to assist the excision of biopsy-proven or suspected metastatic axillary lymph nodes.
Methods: A retrospective chart review of all suspected or biopsy-proven node positive patients who underwent RRL of an axillary lymph node to guide surgical extirpation as a selective axillary nodal excision (SANE), targeted axillary dissection (TAD) or axillary lymph node dissection (ALND) between 1/2017 and 5/2018 was conducted. Clinical and demographic data were collected. Descriptive statistics were performed.
Results: A total of 42pts had a radar reflector placed in/adjacent to a biopsy-proven or suspected metastatic axillary lymph node a median of 7.5 days prior to surgery (range: 1-139 days). 33 (79%) nodes had a clip placed at the time of diagnostic biopsy, if one was performed. At the time of surgery, the median pt age was 56 years (range: 21-75 years), with 41 (98%) having ductal histology, 18 (43%) with hormone-positive only breast cancer and 21 (50%) undergoing mastectomy. A total of 9pts (21%) had surgery first, 29pts (69%) after NAC, and 4pts (9.5%) for an axillary recurrence (ipsilateral and contralateral). TAD was performed in 34pts (81%) using dual-tracer sentinel lymph node (SLN) biopsy concurrent with RRL; in 33/34 (97%) specimens the RRL node was also identified as a SLN. One pt failed SLN mapping. Of the remaining pts, 4 (9.5%) underwent ALND alone and 4 (9.5%) underwent RRL SANE. The median number of nodes in a RRL specimen was 1 (range: 1-6). The median number of SLNs removed was 3 (range: 0-9). The radar reflector was recovered in all cases, and surgeons did not report any intraoperative or postoperative complications. The median number of positive nodes in the RRL surgical specimen was 1 (range: 0-3). One pt had a discordant FNA of a suspicious axillary lymph node, final pathology was negative. Of the 29pts having NAC, 29 (100%) RRL nodes were positive or showed treatment effect and 11/29 (38%) had a complete pathologic response.
Conclusion: RRL is feasible to guide excision of suspected or biopsy proven lymph nodes in the axilla of a breast cancer patient and can be utilized with minimal risk of complications. Further investigation is warranted to compare RRL to WL.