Comparative efficacy of indocyanine green and Tc-99m for sentinel lymph node biopsy in breast cancer: Upfront surgery and post-neoadjuvant chemotherapy

Abstract

Background: This retrospective study aimed to compare the sensitivity of sentinel lymph node (SLN) detection using indocyanine green (ICG), Technetium-99 (Tc-99m), and combined technique (ICG + Tc-99m) in clinical node-negative early-stage breast cancer patients, both in upfront surgery and post-neoadjuvant chemotherapy (NAC) settings. Method: Breast cancer patients who underwent breast surgery with SLN biopsy from December 2021 to May 2024 were enrolled. Both ICG and Tc-99m were used in combination during the SLN biopsy. The primary outcome was the SLN detection rate (per case) and nodal detection rate (per node) compared between ICG, Tc-99m, and combined technique. Results: 176 patients (128 upfront surgery, 48 post-NAC) were analyzed and a total of 326 SLNs were identified. The SLN detection rate was not different between ICG and Tc-99m in upfront surgery (96.1 % vs. 95.3 %, P = 0.65) and post-NAC (89.6 % vs. 85.4 %, P = 0.41). The mean number of identified SLNs was higher with ICG compared to Tc-99m (1.6 ± 1.0 vs. 1.4 ± 0.9, P < 0.001). ICG exhibited a higher overall nodal detection rate than Tc-99m (86.2 % vs. 74.2 %, P < 0.001). Using the combined technique significantly increased the SLN detection rate particularly in post-NAC compared to Tc-99m alone (93.8 % vs 85.4 %, P < 0.05) with a false negative rate of 2.1 %. Conclusions: ICG demonstrated high sensitivity for SLN detection, comparable to Tc-99m in both upfront surgery and NAC settings. Using dual tracers also significantly improved the SLN detection rate in post-NAC setting, suggesting that ICG may serve as an effective alternative tracer for SLN mapping, regardless of NAC.