Absence of residual fluorescence in the surgical bed at near-infrared fluorescence imaging predicts negative margins at final pathology in patients treated with breast-conserving surgery for breast cancer

Abstract

Introduction: Positive margins after breast-conserving surgery (BCS) for breast cancer (BC) remain a major concern. In this study we investigate the feasibility and accuracy of indocyanine green (ICG) fluorescence imaging (FI) for the in vivo assessment of surgical margins during BCS.

Materials and methods: Patients with BC admitted for BCS from October 2015 to April 2016 were proposed to be included in the present study (NCT02027818). ICG (0.25 mg/kg) was intravenously injected at induction anesthesia and ICG-FI of the surgical beds was correlated with final pathology results.

Results: Fifty patients consented to participate and thirty-five patients were retained for final analysis, 15 patients having been excluded for, respectively, incomplete video records data for signal to background ratio (SBR) calculation (11) and in situ tumors (4). The final pathological assessment of 35 breast specimens identified 5 (14.7%) positive margins. Intraoperative ICG-FI revealed hyperfluorescent signals in 15 (42.9%) patients and an absence of fluorescent signals in 20 (57.1%). Median SBR in patients with involved margins was 1.8 (SD 0.7) and was 1.25 (SD 0.6) in patients with clear margins (p = 0.05). The accuracy, specificity, positive and negative predictive value of ICG-FI for breast surgical margin assessment were 71%, 60%, 29% and 100%, respectively.

Conclusion: ICG-FI of BC surgical beds has a high negative predictive value for surgical margin assessment during BCS. The absence of residual fluorescence in the surgical bed of patients with fluorescent tumors predicts negative margins at final pathology and allows the surgeon to avoid further intraoperative analysis.

Keywords: Breast-conserving surgery; Indocyanine green; Residual tumor; Surgical margin.