109: THE IGREENGO STUDY. CLINICAL ROLE OF INDOCYANINE GREEN IMAGING FLUORESCENCE IN SURGICAL TREATMENT OF ADVANCED GASTRIC CANCER. STUDY PROTOCOL

Abstract

Abstract Background and aim Near infra-red/indocyanine green imaging fluorescence (NIR/ICG) technology is showing promising results in several fields of surgical oncology. However, the clinical value of NIR/ICG technology in the surgical treatment of advanced gastric cancer (AGC) is not clearly established. Indeed, although lymphadenectomy is one of the main steps in curative-intent surgery for gastric cancer and lymph node status is the most important prognostic factor for survival, several questions have risen in literature on considering the overall number of harvested lymph nodes as the best indicator of the NIR/ICG technology clinical value. At present, no data exist regarding the ability of NIR/ICG technology to modify the surgical conduct at the moment of lymphadenectomy. Methods This is the ‘iGreenGO’ (indocyanine Green Gastric Observation) study protocol: an international, prospective, multicentre study. Study population will be a cohort of Western patients undergoing preoperative upper gastrointestinal endoscopy with submucosal peritumoral ICG injection followed by curative-intent minimally invasive gastrectomy with D2 lymphadenectomy for locally AGC. High-volume western academic and non-academic hospitals will be allowed to participate in the study. The primary endpoint will be the ‘change of the surgical conduct’ (CSC) at the moment of intraoperative NIR/ICG technology activation after completing a D2 lymphadenectomy ‘with the naked eye’. Key secondary endpoints will be the identification of preoperative clinical variables potentially associated with CSC, the number of additional LNs retrieved and pTNM stage migration using NIR/ICG technology, abdominal fluorescence location according to patient’s and tumor’s characteristics. Results The sample size was calculated by considering the estimated incidence of intraoperative change of the surgical conduct when using NIR/ICG technology. Data from the literature indirectly suggest an approximate rate of such event around 17%. A sample size of 350 patients will be necessary to obtain a measurement with an estimated precision of 4% with a confidence level of 1-alfa = 95%. Conclusion The iGreenGO study will be the first western study to investigate the intraoperative clinical role of NIR/ICG technology in surgical treatment of AGC in a large cohort of Western patients. Results from the present study can further clarify the role of the NIR/ICG technology in helping the surgeon during lymphadenectomy for AGC.