Indocyanine green identification for tumor infiltration or metastasis originating from hepatocellular carcinoma

INTRODUCTION: The indocyanine green-photodynamic eye (ICG-PDE) system is useful to detect small hypervascular liver tumors, hepatocellular carcinoma (HCC), on the liver surface. This system may be also applied to improve determining the location of metastasis or tumor thrombus (TT). We herein report three case reports. ICG was administered preoperatively for functional testing and images of the tumor were observed during hepatectomy using a PDE camera. CASE SERIES: The patient in case 1 exhibited advanced HCC with TT in the portal trunk. The TT in the right portal vein was clearly fluorescent by ICG-PDE and the right portal vein was adequately transected to remove TT. The patient in case 2 exhibited a large HCC in the right liver and the right adrenal gland was simultaneously swollen with enhancement. By confirming the fluorescent spot in the right adrenal gland, the metastasized lesion was completely resected. The patient in case 3 previously underwent central bi-segmentectomy, and lymph node metastasis and TT in the vena cava was observed during one-year follow-up. Although it was difficult to detect the definite margin of these lesions by the outline appearance, both lesions could be clearly observed with strong fluorescence and were completely resected. DISCUSSION AND CONCLUSION: ICG-PDE is a useful tool for detecting the precise tumor location even in extrahepatic tumor lesions, such as metastases or tumor thrombus, which is useful for deciding which parts to resect.