Possibilities of indocyanine green-based visualization methods in gastric cancer surgery

Radical gastrectomy with D2 lymphadenectomy remains the primary treatment method for gastric adenocarcinoma. However, lymph node dissection in gastric cancer surgery is sometimes performed incompletely and is not accompanied by additional imaging techniques. Consequently, comprehensive lymphadenectomy is challenging. It leads to reduced volume of dissected lymph node. This study assessed the safety of gastric tumor marking and the frequency of Sentinel Lymph Node (SLN) detection through fluorescent imaging for intraoperative navigation using IndoСyanine Green (ICG) in gastric cancer. We conducted single-arm prospective observational study. The study included patients who met the inclusion criteria, underwent diagnostic laparoscopy for gastric cancer staging and received 2 to 4 cycles of neoadjuvant chemotherapy following either the FLOT (Fluorouracil, Leucovorin, Oxaliplatin and docetaxel) or FOLFOX (FluOrouracil, Leucovorin, OXaliplatin) regimen. Radical gastrectomy or distal subtotal gastric resection was performed after the neoadjuvant phase. At least one SLN was detected in 23 out of 25 patients. Among these 23 patients, the mean number of fluorescently visualized lymph nodes was 5.8±4.2 per individual patient. Among the 23 patients with identified fluorescent lymph nodes, 20 (86.9%) had at least one metastatic fluorescent lymph node, suggesting a potential tendency for contrast accumulation in metastatic lymph nodes. IGC can be safely employed for intraoperative navigation and determining the extent of lymph node dissection in gastric cancer surgery. It is safe for patients and does not induce acute or long-term adverse reactions. The use of ICG does not prolong the duration of surgical intervention and enhances intraoperative navigation through simple and accessible visualization of SLN. Keywords: sentinel lymphatic nodule, intraoperative navigation, lymphadenectomy.