Fluorescence Guided Laparoscopic-Endoscopic Cooperative Sentinel Lymph Node Navigation Surgery Strategy for Early Gastric Cancer（IDEAL Stage 2b）

Inclusion Criteria: * 1\) Patients aged 18-80 years, regardless of gender. 2) Patients with Eastern Cooperative Oncology Group (ECOG) score ≤ 2 and American Society of Anesthesiologists (ASA) score ≤ 2 who are candidates for a curative D2 gastrectomy. 3\) Patients without prior gastrointestinal surgery, chemotherapy, or radiotherapy. 4\) Patients with normal liver, kidney, heart, lung, and bone marrow function (GPT × 109 /L, PLT\>109 /L). 5\) Patients capable of understanding and adhering to the research protocol. 6) Patients who can provide written informed consent, either personally or through legal representative. 7\) Patients with cT1N0M0 gastric cancer or after non-curative ESD resection, according to the UICC TNM staging system, 8th edition. Exclusion Criteria: * 1\) Patients with a contraindication for gastroscopy. 2) Patients with uncontrollable diseases, such as coagulation disorders, epilepsy, central nervous system diseases or mental disorders, cardiopulmonary insufficiency, unstable angina, myocardial infarction, a cerebrovascular accident that occurred within 6 months, and other surgical contraindications. 3\) Patients unable to undergo general anesthesia or surgical treatment due to conditions related to other organs, or unwilling to undergo surgery. 4\) Patients with gastric stump cancer, recurrent gastric cancer, multiple primary malignant tumors in the abdominopelvic cavity, or a history of other malignant tumors within the previous 5 years. 5\) Pregnant or lactating women. 6) Participants enrolled in other clinical trials. 7) Patients with undeterminable tracer staining range or contraindications to tracer use. 8\) Patients who fail to receive or fail ESD therapy. 9) Patients who meet the absolute indication of ESD.