Near-infrared Imaging With Indocyanine Green for Detection of Peritoneal Metastases for Gastric Adenocarcinoma.

Diagnostic Value of Intraoperative Near-infrared Imaging With Indocyanine Green for Detection of Peritoneal Metastases During Staging Laparoscopy for Gastric Adenocarcinoma: a Prospective, Multicentric Study.

Peritoneal disease at initial presentation for patients with gastric adenocarcinoma (GA) is frequent, with 15-31% of patients presenting with peritoneal metastases (PM) at surgical exploration. The prognosis of patients with PM is poor, overall survival (OS) ranging from 8 to 13 months, reinforcing the importance of optimal patient selection before surgical management of GA.

Indocyanine Green (ICG) fluorescence imaging for intraoperative detection of PM has been described in recent literature as a useful tool in patients undergoing cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal malignancies to increase the detection of PM during surgery. However, the role of ICG for patients with GA, and its role during diagnosic laparoscopy (DL), remain unknown.

This is a multicentric, prospective study . Patients will be referred to one of seven surgeons specialized in the surgical management of gastric cancer. Patients will undergo DL, with intravenous (IV) injection of 0.25 mg/kg of free ICG at the start of the surgery. DL will be first performed without fluorescence imaging in the standard fashion, with identification of potential PM. A first peritoneal cancer index (PCI) score will be calculated. Fluorescence imaging will then be performed, and correlation with previously identified lesions will be assessed and a second PCI score (with ICG) will be calculated. Biopsies will be performed to confirm the metastatic status of the lesions. Any suspicion for additional lesions visualized only under fluorescence imaging will be biopsied as well. Peritoneal fluid cytology will be performed at the beginning of the surgery.

Inclusion Criteria:

• Confirmed diagnosis of gastric adenocarcinoma.
• Clinical stage cT2 or higher.
• No evidence of metastatic disease on preoperative imaging.
• Patient fit for surgery (ECOG 0 or 1).

Exclusion Criteria:

• Indocyanine allergy.
• Gastric cancer subtype other than gastric adenocarcinoma.
• Unconfirmed diagnosis of gastric adenocarcinoma (unable to confirm diagnosis).
• Clinical stage cT1b or lower.
• Evidence of metastatic disease on preoperative imaging.
• Patient unfit for surgery (ECOG 2 or more).