Abstract P1-16-10: Pilot study of a passive non-radioactive electromagnetic wave technology to localize non-palpable breast lesions
Authors: Cox Charles E , Themar-Geck Melissa , Prati Ronald , Jung Michelle , King Jeff , Shivers Steven C 
Published: May 2015

Background and Objectives: The standard preoperative technique for localizing non-palpable breast lesions is wire localization (WL). Radioactive seed localization (RSL) has been described as an alternative approach to address the number of clear disadvantages associated with WL. Yet, despite its proven advantages, the adoption of RSL has been impacted by considerable regulatory requirements for the handling of radioactive materials. To advance the progress made with RSL and eliminate the issues associated with radioactive components, the SAVI Scout® surgical guidance system has been developed.

The SAVI Scout surgical guidance system is an FDA-cleared medical device that utilizes passive non-radioactive electromagnetic wave technology to provide real-time guidance during excisional breast procedures. The purpose of this pilot study is to determine the safety and efficacy of the SAVI Scout system in localizing and directing the removal of non-palpable breast lesions during excisional biopsy and lumpectomy procedures. The preliminary results from two institutions are reported.

Materials and Methods: Following a feasibility study using the SAVI Scout system in resected breast tissues ex vivo, Institutional Review Board approval was granted for both institutions for women with a non-palpable breast lesion requiring preoperative localization for excision. Participating patients underwent localization and excision with the SAVI Scout system, which consists of an electromagnetic wave reflective device (reflector), handpiece and console. Using mammographic or ultrasound guidance, the reflector was placed percutaneously up to 7 days prior to the scheduled excisional procedure. At surgical excision, the surgeon used the SAVI Scout handpiece to locate the reflector, which was removed along with the surrounding breast tissue. The console provides audible feedback of reflector proximity to the handpiece. Successful reflector placement, localization and retrieval were the primary endpoints.

Results: After the first training case (data not used), a total of 17 patients have participated in the study to date. The reflectors were successfully placed with mammographic guidance in 9/9 patients and with ultrasound guidance in 8/8 patients. Reflectors were placed an average of 1.7 days (range 0-6 days) before surgery. Five patients underwent excisional biopsy and 12 patients had a lumpectomy. The intended lesion and reflector were successfully removed in 17/17 patients. Reflector migration did not occur and no adverse events occurred. Of the 14 patients in which final pathology is currently available, 6 patients had no invasive or in situ carcinoma identified, 4 had no tumor in the excision, and 3/4 patients with tumor had clear margins. One patient had a focally positive margin and was recommended for re-excision.

Conclusions: The preliminary data show the SAVI Scout system to be a safe and effective tool for the localization of non-palpable breast lesions. Ongoing accrual to this pilot study will validate these findings with planned enrollment of a total of additional 50 patients in the next 60 days at up to 3 additional sites.

Citation Format: Charles E Cox, Melissa Themar-Geck, Ronald Prati, Michelle Jung, Jeff King, Steven C Shivers. Pilot study of a passive non-radioactive electromagnetic wave technology to localize non-palpable breast lesions [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-16-10.