Abstract P3-13-08: A prospective, single-arm, multi-site, clinical evaluation of the SAVI SCOUT® surgical guidance system for the location of non-palpable breast lesions during excision
Authors: Cox CE , Prati R , Blumencranz P , Allen K , Banull C , Cline M , Howard T , Portillo M , Whitworth P , Funk K , Police A , Lin E , Combs F , Anglin B , King J , Shivers SC 
Published: May 2016

Background and Objectives: The standard preoperative technique for localizing non-palpable breast lesions is wire localization (WL). Radioactive seed localization (RSL) is an alternative approach that addresses a number of clear disadvantages associated with WL but, 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 issues associated with radioactive components, the SAVI SCOUT® surgical guidance system was developed. SAVI SCOUT is an FDA-cleared medical device that utilizes non-radioactive electromagnetic wave technology to provide real-time guidance during excisional breast procedures. The purpose of this study is to evaluate the performance of SAVI SCOUT in guiding the removal of non-palpable breast lesions.

Methods: Following a 50 patient pilot study that showed SAVI SCOUT to be safe and effective, IRB approval was granted for this prospective, single-arm, multi-site study for women with a non-palpable breast lesion. Pts 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 implanted into the target tissue. Before making an incision, the surgeon used the handpiece, which emits electromagnetic waves and infrared light, to detect the location of the reflector and subsequently plan the surgical incision. During the procedure, the surgeon used the handpiece to guide the localization and removal of the reflector 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: A total of 61 pts have participated in the study to date, along with 7 surgeons and 9 radiologists across 6 institutions. The reflectors were successfully placed in all pts, including 27 under mammographic guidance and 34 under ultrasound guidance. In 28 cases, the reflectors were placed on the same day as surgery. Otherwise, the reflectors were placed up to 7 days (average 2.9 days) before surgery. Thirteen pts underwent excisional biopsy and 48 pts had a lumpectomy. The intended lesion and reflector were successfully removed in all pts. Reflector migration did not occur and no adverse events occurred. Final pathology is currently available for 52 pts: 8/10 excisional biopsy pts had no invasive or in situ carcinoma identified. For pts with cancer and complete data, 39/39 had clear margins, but one patient was recommended for re-excision due to a close margin (1 mm) for DCIS.

Conclusions: The preliminary data from this prospective, multi-site study show that real-time surgical guidance with SAVI SCOUT is an accurate technique for directing the removal of non-palpable breast lesions and is reproducible at multiple clinical sites. At present, the study has yielded 100% surgical success with a re-excision rate of 3.0%. Ongoing accrual to this clinical evaluation study will validate these findings with planned enrollment of 150 pts at up to 15 total sites.

Citation Format: Cox CE, Prati R, Blumencranz P, Allen K, Banull C, Cline M, Howard T, Portillo M, Whitworth P, Funk K, Police A, Lin E, Combs F, Anglin B, King J, Shivers SC. A prospective, single-arm, multi-site, clinical evaluation of the SAVI SCOUT® surgical guidance system for the location of non-palpable breast lesions during excision. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-13-08.