Clinical Implications of Indocyanine Green Fluorescence Imaging‑Guided Laparoscopic Lymphadenectomy for Patients With Gastric Cancer: Pooled Analysis From Two Randomized, Controlled Trials Using Individual Patient Data

Background: The value of indocyanine green (ICG) fluorescence imaging in tracing metastatic lymph nodes (LNs) has rarely been reported. We aimed to evaluate the clinical implications of fluorescence imaging‑guided lymphadenectomy and the sensitivity of fluorescent lymphography to detect metastatic LN stations in gastric cancer (GC). Methods: This analysis pooled data from two randomized controlled trials (FUGES-012 and FUGES-019 studies) on laparoscopic ICG tracer-guided lymphadenectomy for GC between November 2018 and October 2020. The ICG group received ICG injection using either the intraoperative subserosal or submucosal approaches 1 day before surgery and underwent fluorescence imaging‑guided lymphadenectomy. The non-ICG group underwent conventional lymphadenectomy without intraoperative imaging. Findings: Among 514 enrolled patients, the ICG and non-ICG groups included 385 and 129, respectively. A significantly higher mean number of LNs was retrieved in the ICG group than in the non-ICG group (49.9 vs. 42.0, P<0.001). The ICG group showed a lower LN noncompliance rate than that in the non-ICG group (31.9% vs. 57.4%, P<0.001). The sensitivity of fluorescence imaging for detecting all metastatic LN stations was 86.8%. The negative predictive value was 92.2% for nonfluorescent stations. For detecting all metastatic stations, subgroup analysis revealed 97.7%, 91.7%, 86.2%, and 84.3% sensitivities for pT1, pT2, pT3, and pT4a tumors, respectively. Regardless of gastrectomy type, the diagnostic accuracy for detecting all metastatic stations in the D1+ and D2 stations for cT1–cT2 disease reached 100%. Interpretation: ICG fluorescence imaging assisted in the thorough dissection of potentially metastatic LNs, as recommended for individualized laparoscopic lymphadenectomy for GC. Funding Information: This study is supported by the Graduate Innovation Project of Sailing Fund of Fujian Medical University (2020QH2028) Funds for Outstanding Experts of Fujian Health Commission (2019[153]), the Second Batch of Special Support Funds for Fujian Province Innovation and Entrepreneurship Talents (2016B013), Joint Funds for the Innovation of Science and Technology of Fujian Province (2018Y9041), National Natural Science Foundation of China (82002462), Natural Science Foundation of Fujian Province (2020J011001) and the China Scholarship Council (No. 201908350095). Declaration of Interests: The authors have declared that no competing interest exists. Ethics Approval Statement: The study was conducted in accordance with the guidelines of the Declaration of Helsinki, and was approved by the Ethics Committee of Fujian Medical University Union Hospital (IRB number: 2021KY042). Patient consent was waived due to the retrospective design of this study.