Infrared fluorescence endoscopy for the diagnosis of superficial gastric tumors

BackgroundIndocyanine green (ICG) is a fluorescent marker that is excited by rays at a wavelength of 768 nm to emit fluorescence at a wavelength of 807 nm in the infrared (IR) range. We developed an IR fluorescence endoscope (IRFE) to observe superficial gastric tumors and assessed its clinical usefulness.ObjectiveTo evaluate the clinical usefulness of an IRFE for the assessment of superficial gastric tumors.DesignAn observational study.SettingUniversity hospital.InterventionsNewly developed IRFE.PatientsThirty patients with gastric tumors were enrolled in this study, and their lesions were subjected to endoscopic submucosal dissection (ESD), or laparoscopic gastrectomy after observation with the IRFE.MethodsGastric lesions were subjected to conventional observation, followed by IR fluorescence observation before and after intravenous ICG (0.01 mg/kg) injection.Main Outcome MeasurementsThe relationship between the positive fluorescence and invasivity of each tumor.ResultsFluorescence was positive in 8 of 10 gastric cancers with submucosal invasion (80%) and 1 of 20 adenomas or intramucosal gastric cancers (5%); the difference was statistically significant (P < .01).ConclusionIRFE is a useful diagnostic tool for estimating the invasivity of gastric tumors.