CLO20-037: Time is On Our Side: Concomitant Needle Biopsy and Wire-Free Localization of Axillary Lymph Nodes May Decrease Redundant Preoperative Needle Localization in BI-RADS 5, 6 Breast Cancer Patients

Background: Accurate axillary lymph node (LN) staging impacts prognosis and treatment. Breast surgeons use pre- and post neoadjuvant chemotherapy (NACT) findings to plan extent of axillary LN surgery. NACT confers an excellent treatment response in 41-74% of patients and allows for de-escalated LN surgery. Preoperative localization (LOC) of the biopsied (BX) LN improves the 23-25% false negative (FN) axillary LN surgery staging rate to 2-7%. Surgeons proceed with de-escalated selective LN surgery based on the intraoperative pathology of the excised LN. An excellent response post-NACT with a “normalized” BX LN is often poorly visualized and limits LN LOC to 72% success rate. Therefore, a clinical practice of LN BX and up front WFL, when the abnormal LN is best visualized, is evolving. Materials and Methods: In this IRB-approved HIPAA-compliant study retrospective study, we reviewed all patients who had SCOUT WFL (Cianna Medical, Inc. Aliso Viejo, CA, USA) placed at the time of LN BX between August 2017 and May 2019. Time (days) to surgery, number of LN procedures, complications were recorded from radiology, surgery, pathology records. Descriptive statistics were calculated using spreadsheet software (Excel 2013, Microsoft). Results: There were 52 US-guided LN BX with concomitant SCOUT WFL performed in 48 BI-RADS 5, 6 women. The mean age was 52 years (range 28-74 years). All (100%) up-front SCOUT WFL were successful. Of the 32 patients who completed surgery to date, all (100%) had successful LN excision without complication. The mean time interval between WFL and surgery was 162 days (range 4-270, median 191 days). A single supplementary wire was performed for surgeon’s learning curve. No obscuring artifact was noted in 25 MRI exams. Conclusion: In BI-RADS 5-6 patients, LN BX with concomitant WFL performed up-front when the lesion is best visualized, improves LOC success, preserves options to de-escalate surgery, decreases redundant technically challenging pre-operative LN LOC, and causes no harm to standard of care MRI for diagnosis/re-staging of adjacent breast, axilla, chest wall or brachial plexus tissues. This information supports a clinically relevant paradigm shift for patients who will likely require LN surgery. Larger scale outcomes study is needed with data for comparison of costs associated with the device, OR start time delay, additional appointments saved, number of WFL patients with no LN surgery, accuracy of LOC and department staffing.