S. Zheng1, S.L. Blair2, J. Kim3, C.K. Thompson1, N.J. Juarez1, J.L. Baker1, A. Labora1, C. Tseng3, W. Peacock1, N.S. Kapoor1 1University Of California – Los Angeles, Department Of Surgery, Los Angeles, CA, USA 2University Of California – San Diego, Department Of Surgery, San Diego, CA, USA 3University Of California – Los Angeles, Department Of Biostatistics, Los Angeles, CA, USA
Introduction: Breast tumor localization is crucial for identifying non-palpable lesions. Traditional preoperative wire-localization has shifted toward wire-free devices or intraoperative ultrasound-guided localization with the aid of ultrasound visible biopsy clips. This study evaluates a new localization system, the OneMark clip and console, which utilizes novel doppler technology embedded with nanoparticles that emit an audible signal plus visual overlay and compares it to standard target lesions in a training setting.
Methods: Residents completed a baseline survey and received a lecture on ultrasound-guided breast procedures followed by a laboratory session to practice ultrasound, biopsy, and localization of target lesions implanted in chicken breasts and fresh female human cadaver breasts. Target lesions included standard olives with pimentos, ultrasound visible clips (BD UltraCorTM TwirlTM Breast Tissue Marker), or OneMark clips and Onemark encased in gel as a mass phantom. Residents then entered a testing station to identify eight target lesions in two cadaver breasts. Targets were placed at anterior and posterior depths and included two olives and two biopsy clips in one breast and two OneMark clips and two gelatin-encased OneMark clips in a second breast. Residents were allotted 240 seconds (s) per breast and time to identification of each target was recorded. Residents then completed a post-session survey to rate lesion visibility and confidence with OneMark technology. Statistical analyses were performed using mixed-effects models.
Results: Eleven trainees participated, ranging from 2nd year resident to breast fellow. Most indicated previous ultrasound training, experience with ultrasound-guided procedures, and participation in multiple breast surgeries, but only 6/11 (54.5%) had performed ultrasound-guided breast procedures. On average, all target lesions were identified in less than 45s with the Onemark encased in gel found in the least time at 31s, followed by the clip (35s), the standard OneMark (42s), and lastly the olive (44s). While detection time did not vary significantly by target type, posterior lesions took longer to identify than anterior lesions (52s vs 24s, p = 0.004). Visibility ratings were significantly higher for OneMark clips compared to standard clips (p=0.0001) and almost all participants strongly agreed they could identify OneMark with confidence in any location.
Conclusion: Using a fresh cadaver model, surgical trainees were able to identify all target lesions within 45 seconds. While detection time of target lesions varied minimally, visibility rating of the novel OneMark technology with its audio and visual properties was significantly higher than standard breast target lesions.