ICG (Indocyanine Green) Imaging Fluorescence Technology in Surgical Treatment of Advanced Gastric Cancer

Near infra-red/ indocyanine green imaging fluorescence (NIR/ICG) technology is showing promising results in several fields of surgical oncology.

The clinical value of NIR/ICG (near infrared range/indocyanine green) technology in surgical treatment of advanced gastric cancer (AGC) is not clearly established and data regarding whether its application is associated with a change of the intraoperative surgical conduct are lacking in literature.

This is the "iGreenGO (indocyanine Green Gastric Observation) Study" protocol: an international, prospective, multicentre, study.

Study population will be a cohort of western patients who will undergo preoperative upper gastrointestinal endoscopy at the most 20 hours before surgery (intraoperative endoscopic injection before starting surgical dissection is also allowed) with submucosal peritumoral ICG injection and curative-intent gastrectomy with D2 lymphadenectomy for locally AGC.

The primary endpoint will be the incidence of "change of the surgical conduct" (CSC) at the moment of intraoperative NIR/ICG technology activation after a D2 lymphadenectomy performed "with the naked eye". Secondary endpoints will be the preoperative clinical variables potentially associated with CSC, the pattern of abdominal fluorescence distribution according to tumor and patient characteristics, the number of additional lymph nodes retrieved using NIR/ICG technology, the incidence of stage migration due to NIR/ICG application, 90-day morbidity and mortality The iGreenGO Study will be the first Western study to investigate the clinical role of NIR/ICG technology for surgical treatment of AGC in a large cohort of western patients. Results from the present study could provide novel information about which help NIR/ICG technology can supply to surgeons during lymphadenectomy for AGC and the patterns of ICG abdominal fluorescence distribution according to tumor and patient characteristics, which are unanswered questions at present time.

Inclusion criteria

• Age ≥ 18 years old
• Preoperative histologically proven adenocarcinoma of the upper, middle or lower part of the stomach.
• Advanced disease (Staged cT2-T4a, N0-3;M0 according to 8th edition of the AJCC TNM Staging System) at diagnosis, in which resection can be safely achieved by distal or total gastrectomy with D2 lymphadenectomy via a minimally invasive (laparoscopic or robotic) approach, either as first treatment or after neoadjuvant treatment
• No distant metastasis, no direct invasion of pancreas, spleen or other organs nearby in the preoperative and intraoperative examinations
• Written informed consent

Exclusion criteria

• Women during pregnancy or breast-feeding
• History of previous upper abdominal surgery (laparoscopic cholecystectomy will be allowed)
• History of previous gastrectomy, endoscopic mucosal resection or endoscopic submucosal dissection
• History of allergy to iodine agents
• Cancer located at the esophago-gastric junction (Siewert I, II, III tumors 29)
• Patients candidates to transthoracic esophagectomy, transhiatal extended gastrectomy or proximal gastrectomy
• History of previous neoadjuvant chemotherapy (except perioperative chemotherapy for gastric cancer) or radiotherapy