Clinical application of fluorescence imaging of liver cancer using indocyanine green

Recently, fluorescence imaging using indocyanine green (ICG) has been applied to hepatobiliary surgery, not only to visualize the bile ducts, but also to identify liver cancer during surgery. In this technique, ICG is administered intravenously at a dose of 0.5 mg/kg body weight for routine liver function testing before surgery. Intraoperatively, liver cancer can be readily identified by fluorescence imaging on the liver surface before resection and on the cut surface of the resected specimen. This is achieved by visualizing fluorescence from the area of impaired bile excretion in hepatocellular cancer tissue and in the liver parenchyma surrounding metastatic liver cancers. Liver cancer navigation surgery, first developed in Japan, is also possible, and it represents one of the few fluorescence imaging techniques for cancer that have reached the stage of clinical application; with further developments in basic research, fluorescence imaging is expected to become an indispensable technique for the diagnosis and treatment of liver cancer.