Identification of liver lesions using fluorescence imaging: comparison of methods for administering indocyanine green

Abstract

BackgroundFluorescence imaging using indocyanine green (ICG) enables intraoperatively visualizing liver tumors as fluorescent. This study evaluated the doses and timing of ICG administration for visualizing tumors via fluorescence using near-infrared light camera systems. MethodsConsecutive patients who underwent open liver resection for liver tumors from 2016 to 2017 were included. ICG was intravenously injected one-day before surgery at 0.25 mg-intravenous injection (IV), 1.25 mg-IV, 2.5 mg-IV, or 3.75 mg-IV. No additional ICG was administered when patients underwent ICG (0.5 mg/kg) retention test within 10 preoperative days. The ability of fluorescence imaging to enable identifying liver tumors was compared using the PDE-NEO and PINPOINT. Results154 lesions in 82 patients were assessed. The tumor identification rate of PDE-NEO did not differ significantly among dosages. The positive predictive values of PDE-NEO were significantly lower at 3.75 mg-IV (69.0%) than in the control group (92.0%) (p = 0.036) and at 1.25 mg-IV (88.9%) (p = 0.033). The tumor identification rate of PINPOINT was significantly higher at 3.75 mg-IV (82.4%) than at 1.25 mg-IV (60.0%) (p = 0.035). The positive predictive values of PINPOINT did not significantly differ among dosages. ConclusionAdministering 2.5 mg of ICG one-day before surgery can enable identifying tumors via fluorescence imaging when the ICG test was not performed within 10 preoperative days.