Efficacy of Indocyanine Green-Guided Lymphatic Mapping in the Gastric Cancer Lymphadenectomy: Impact of Neoadjuvant Chemotherapy.

Background: Indocyanine green (ICG) fluorescence has recently been introduced as an imaging technique to enhance lymphatic mapping in gastric cancer (GC) surgery. This study analyzes the efficacy of this tool in gastric cancer lymphadenectomy and the influence of neoadjuvant chemotherapy (NAC) on its application.

Material and methods: This study analyzes seventy-two patients from a Spanish center with gastric adenocarcinoma who underwent gastrectomy between October 2018 and December 2023. Two groups were compared: patients undergoing oncologic gastrectomy with ICG-guided lymphadenectomy versus patients with conventional lymphadenectomy. Primary outcomes were the number of lymph nodes (LN) retrieved and adequate lymphadenectomy rates (≥16 L N).

Results: The study population comprised 72 patients, of whom 36 belonged to the ICG group and 36 to the non-ICG group. Both groups had similar mean age, BMI, sex ratios, comorbidities, and staging. The rate of adequate lymphadenectomy was significantly higher after intraoperative ICG guidance (86.1% vs. 58.3%; p = 0.009), although this association was not significant after NAC. There were no differences in the mean number of lymph nodes retrieved. A greater number of postoperative complications was observed in the ICG group, although no statistically significant differences were found. None of these complications were directly related to indocyanine green instillation. There were also no differences in the length of hospital stay between the two groups.

Conclusion: ICG-guided lymphatic mapping appears to be a safe and effective tool for achieving adequate lymphadenectomy in gastric cancer compared to conventional lymphadenectomy. However, NAC may limit the effectiveness of the technique.