A randomized trial of combined indocyanine green and endoscopic ultrasound for lymph node evaluation in gastric cancer surgery.

[BACKGROUND] Accurate lymph node detection plays a critical role in the staging and prognosis of gastric cancer, yet conventional techniques often suffer from limited sensitivity or operator dependency. Indocyanine green (ICG) fluorescence imaging has emerged as a promising tool to enhance intraoperative lymph node visualization, while endoscopic ultrasound (EUS) offers real-time structural assessment. This study aims to investigate the effectiveness of a precise intraoperative navigation system for gastric cancer, constructed using ICG fluorescence tracing technology in conjunction with EUS.

[METHODS] A total of 26 patients who underwent radical gastric cancer surgery at Northern Jiangsu People's Hospital from September 1 to October 31, 2024, were included in this study and randomly divided into two groups: the ICG group (n=13) and the non-ICG group (n=13). The ICG group utilized ICG fluorescence tracing technology during the operation, which was subsequently combined with EUS to evaluate the lymph nodes postoperatively. The main observation indicators included the total number of lymph nodes, the number of positive lymph nodes, and the correlation between the ICG tracing results and the presence of positive lymph nodes. Additionally, a comparative analysis of the pathological tissue morphology and EUS images in the ICG group was performed.

[RESULTS] There were no statistically significant differences in the baseline characteristics [age, sex, body mass index (BMI), clinical stage] between the two patient groups (P>0.05). The number of lymph nodes detected in the ICG group was significantly higher than that in the non-ICG group (41.15 . 26.62, P<0.05). Although the number of positive lymph nodes detected (7.38 . 4.77) was higher, there was no significant difference (P>0.05). The sensitivity of EUS in determining the depth of infiltration was 84.62%, the specificity was 92.31%, and the consistency was good (Kappa =0.76). The lymph node detection rates for ICG and ICG combined with EUS were 85.78% and 94.71% respectively (P<0.05), with coverage rates of 58.95% and 67.92% respectively (P<0.05), and Kappa values were 0.77 and 0.89. ICG combined with EUS showed significant advantages in identifying tumor boundaries, positive lymph nodes, and subfat lymph nodes. These findings were supported by both histomorphological analysis and EUS imaging.

[CONCLUSIONS] The combination of ICG and EUS navigation systems can significantly enhance the accuracy and quality of lymph node detection during radical gastric cancer surgery, thereby offering a novel approach for precise navigation.

[TRIAL REGISTRATION] The project has been registered with the Chinese Clinical Trial Registry (ChiCTR2400090495).