Research purpose Patients with locally advanced gastric adenocarcinoma (CT2-4A N-/+ M0) were selected as study subjects to investigate the safety, efficacy, and feasibility of ICG near-infrared imaging tracing in guiding laparoscopic D2 lymph node dissection for gastric cancer by comparing injection ICG group and non-injection ICG group~Research design prospective, multicenter, randomized controlled, open-control, Parallel assignment, superiority test 2.1 multicenter This study came from Fujian Medical university union hospital, Beijing University Cancer Hospital, Zhongshan Hospital, Fudan University, The First Hospital of Pu Tian City, Zhangzhou Affiliated Hospital of Fujian Medical University, Affiliated Cancer Hospital of Harbin Medical University, The first affiliated Hospital of Ji Lin University ,Nan fang Hospital, Southern Medical University, The first affiliated Hospital of Nan Jing University, Affiliated Hospital of Qinghai University, Qi Lu Hospital of Shang Dong University, Ren ji Hospital, Shanghai Jiao Tong University School of Medicine, Air Force Medical University（Fourth Military Medical University）Tang du Hospital, The first affiliated Hospital of USTC AnHui Provincial Hospital, Cancer Hospital Chinese academy of Medical Science, Sun Yat-Sen University Cancer Center, which jointly attended by 16 centers.~2.2 Case group Group A (Study Group): Laparoscopic gastrectomy Group with the use of near-infrared imaging (ICG group) Group B (Control Group): Laparoscopic gastrectomy Group without the use of near-infrared imaging (Non-ICG group) 2.3 Estimate Sample Size 3 years disease-free survival (DFS) is the main effectiveness evaluation index in this study. The study is superiority test, assuming that the team's three years DFS is better than that of control group,23, according to previous research results of laparoscopic local advanced gastric cancer surgery ,three years DFS is 65.2%, the control group 3 years DFS is 65.2%, assuming that the experimental group 3 years DFS can be increased by 9%, that is 74.2%, inspection level 0.025 (unilateral), take 0.9 inspection efficiency, using PASS 11 Logrank tests (Lakatos)[Proportion surviving] Calculated: Sample size N=428, that is, each group needed 428 people to consider possible exclusion and loss of follow-up cases (20% drop rate). The final sample size for each group was 535 cases, and a total of 1070 cases were initially assigned to 66-67 cases in each center 2.4 randomization Stay into the group of cases after laparoscopic exploration, make sure comply with the standards, can be randomized groups in this study we adopt the central dynamic layered segment randomized method, considering the control factors are age, gender tumor site preoperative staging research center of the given seed number and segment length, application of SAS9.2 programming to produce serial number is 0001 ~ 1070 by corresponding treatment allocation, reserved in the data center and research center has the specialist is responsible for the cases of group information (age, gender tumor site preoperative staging research center) via email A telephone call or text message will be sent to the randomization implementation department of the data center, and the central randomization department will analyze the case information to determine the case enrollment and inform the research center where the case is located 2.5 Blinding Method: This research adopts an open design. 2.6 Research cycle: Estimated enrollment cycle: complete enrollment within 2 years. Follow-up period: the enrollment of the first case and the postoperative pathological report (generally 2 weeks after surgery) was the end point of follow-up for secondary study purposes other than 3-year overall survival rate and 3-year recurrence type Estimated time: 2020.10（to complete enrollment）-2022.09（to complete follow-up）~Study Objects All patients who meet the inclusion criteria and do not conform to the exclusion criteria are qualified for this study.
Patients with locally advanced gastric adenocarcinoma (CT2-4A N-/+ M0) were selected as study subjects to investigate the safety, efficacy, and feasibility of ICG near-infrared imaging tracing in guiding laparoscopic D2 lymph node dissection for gastric cancer by comparing injection ICG group and non-injection ICG group.