Preoperative Radar Localisation of Impalpable Breast and Axillary Lesions: Initial Experience in an Australian Tertiary Centre

INTRODUCTION: Image-guided radar localisation (RL) is a wire-free alternative to hookwire localisation (HWL) for preoperative localisation of impalpable breast and axillary lesions, with potential logistical and technical advantages. This study assesses clinical utility, accuracy of placement and surgical oncologic outcome metrics for RL using the SCOUT reflector compared to HWL after introduction in a tertiary Australian breast service. METHODS: Retrospective comparative cohort analysis of consecutive RL with a contemporaneous historical HWL cohort of similar size (between January 2022 and March 2025) was performed. Key outcome markers included device migration, localisation procedure duration, retrieval issues, surgical margin status and breast malignancy re-excision rates. RESULTS: 287 patients were included (RL n = 144; HWL n = 143). No significant device migration was seen with RL compared to HWL (0.0% vs. 4.2%; p = 0.04) and retrieval issues were less common (4.2% vs. 9.8%; p = 0.10). Excluding MRI placement, procedure duration was shorter with RL (23 min vs. 28 min; p < 0.01). Negative, close, and positive margins were similar and re-excision rates for breast malignancy comparable (12.5% RL vs 16.8% HWL, p = 0.42). CONCLUSION: RL is a safe, accurate localisation technique, demonstrating significantly fewer migration issues and fewer retrieval issues than HWL, while maintaining equivalent surgical oncologic outcomes. It offers logistical benefits of placement at any time prior to surgery (including time-of-biopsy placement), optimisation of radiology and surgical workflows, and versatility of axillary node and MRI-guided placement and compatibility.