Efficacy of Localizing Non-palpable Breast Lesions for Surgical Excision using Surgical Marker Navigation: First Retrospective Multicentre Study Performed in Two United States Breast Cancer Centres

A bstract Background: The Sirius Pintuition GPS Detect TM surgical marker navigation (SMN) system uses directional audiovisual feedback to detect the location of a permanent magnetic marker during surgical resection. This novel directional alignment system provides simultaneous audiovisual feedback of distance (mm) from the surgical marker, as well as directional orientation (TargetLOC TM ) of the navigation probe to the surgical marker during operative resection. This is the first study in the United States (US) to assess the efficacy of this system in localizing non-palpable breast lesions for surgical excision. Materials and Methods: A retrospective analysis of 86 breast cancer patients who underwent preoperative placement of the markers and intraoperative localization from March 2022 to December 2022 at two institutions was included in this study. The efficacy of the SMN system was determined according to the lesion size before and after surgery, the distance to the target lesion on confirmation imaging after placement of the marker, the number of markers placed and retrieved and the surgical margins Results: Eighty-six patients who underwent placement of the magnetic marker and subsequent surgical resection were included in the final analysis. The median lesion size on preoperative imaging was 1.0 cm, interquartile range (IQR): 0.8, and after surgery 1.2 cm on final pathology, IQR: 0.9. A total of 2.3% of patients had positive margins. Patients with positive margins had preoperative lesion sizes which were larger than the median lesion size (2.3 cm vs. 1.2 cm) and larger final pathology size (5.0 cm vs. 1.2 cm). The median distance to the target lesion on confirmation imaging after placement of the marker was 1.0 mm, IQR: 2.0 mm. All t of the markers were retrieved during surgical resection. The average number of days from surgical marker placement to operative removal was 5 days. Eighty-two percent of the magnetic surgical navigation markers were placed under ultrasound guidance. Conclusion: This is the first study in the US to examine the use of the SMN system in non-palpable breast lesions. The system was effective in the localization of the marked lesions. The magnetic markers did not migrate during localization placement or on surgical excision. Users reported that it was easy to use and the directional alignment was beneficial. Further studies are required to examine which factors might lead to decreased incidence of positive margins with localization devices.