Laparoscopic Narrow-Band Imaging for the Diagnosis of Peritoneal Metastasis in Gastric Cancer

BackgroundStaging laparoscopy (SL) is often used to diagnose peritoneal metastasis in patients with advanced gastric cancer, but accurate detection of metastasis can be difficult. We evaluated the usefulness of laparoscopic narrow-band imaging (NBI) versus conventional laparoscopic white-light imaging (WLI) for the diagnosis of peritoneal metastasis.MethodsWe excised 37 white nodules from the parietal peritoneum of 26 patients with gastric cancer and suspected peritoneal metastasis. The WLI and NBI findings were compared with the pathological findings. All the peritoneal lesions examined were observed as white nodules on WLI. Intranodular vessels were evaluated by WLI and NBI for (1) vessel dilatation, (2) vessel tortuousness, (3) vessel heterogeneity, and (4) brown spots.ResultsEach individual abnormal finding had a diagnostic accuracy of less than 79 % with or without NBI. Detection of any one abnormal finding had a sensitivity, specificity, and accuracy of 47.8, 85.7, and 62.2 %, respectively, on WLI and 91.3, 71.4, and 83.8 %, respectively, on NBI, for detection of peritoneal metastasis. Detection of any one abnormal finding on NBI plus clear demarcation of the nodule on WLI had a sensitivity of 91.3 %, specificity of 92.9 %, and accuracy of 91.9 % for detection of peritoneal metastasis. Pathological examination showed that a brown spot detected on NBI correlated with dilated vessels around cancer cells. Vascular endothelial growth factor was expressed in 76.2 % of peritoneal metastases.ConclusionsNBI was more sensitive for the detection of dilated vessels than WLI. NBI could be a useful tool for the diagnosis of peritoneal metastasis during SL.