Comparison between ICG and radioisotope in the identification rate of sentinel lymph node biopsy with the new SPY portable handheld imaging system

Abstract

Background: Fluorescence imaging using indocyanine green (ICG) has the potential to improve the performance of sentinel lymph node (SLN) mapping. This current cohort study was designed to assess the value of the ICG using the SPY Portable Handheld Imaging System (SPY-PHI) to radio-isotope (Rl) in patients undergoing SLN biopsy. Methods: A prospective self-controlled trial was designed to detect the difference in the detection efficacies of ICG and Rl navigation methods. Between 2019 and 2021, 44 breast cancer patients eligible for SLN biopsy were enrolled with 46 SLNs identification and removal procedures under the guidance of ICG and Rl. The patient characteristics, the detection rate of SLNs and positive SLNs were compared. The injection safety of ICG and MB was evaluated. Results: The median age of this cohort is 60.5 (range 31-85), and the median BMI is 21.6 (range 17.9 - 44.5). The identification rate of SLN is 78.3% for ICG and 95.7% for Rl (p=0.01). ICG identified on average 1.93 lymph nodes (range 0-6) while Rl identifies on average 2.24 lymph nodes (range 0-5) with a statistically insignificant difference (p=0.35). In the ICG group comparing the successful to the failed identification group, there is no statistically significant difference in terms of BMI (25.2 +/- 7.7 vs 22.9 +/- 4.2, p=0.22). There were no reports of staining, skin necrosis, or subcutaneous skin nodule. Conclusions: The SLN detection rate is superior in the IR group compared to the ICG group using the SPY-PHI System.