Unexpected Detection of a Sub-millimeter Early Hepatocellular Carcinoma Focus by Intraoperative Near-infrared Fluorescence Imaging

Abstract Background: Intraoperative near-infrared fluorescence (NIRF) imaging became a great assistance to surgeons for precision cancer surgeries. Here, we demonstrate that NIRF was capable of detecting ultra-small hepatocellular carcinoma focus of about 430µm during real time monitored liver cancer surgery. Prognosis of hepatocellular carcinoma is closely related to residual tumor cells and tissues after tumor resection. Thus, close monitoring to ensure a complete removal of residual tumor is primordial. However, up to now, the identification of tiny lesions has not been reported. Herein, we report our findings about a case where tiny lesions were successfully identified by real-time ICG-NIRF imaging. Case presentation: A 55-year-old man, with chronic hepatitis B infection, was preoperatively diagnosed with liver space-occupying lesion. A fluorescence signal was detected on the surface of the liver through the NIRF imaging system. We then tested the residual liver surface and observed a high signal point, less than 1 mm in the right anterior lobe of the liver. Histopathological examination revealed that the tiny fluorescent spot belongs to an early hepatocellular carcinoma focus. Conclusion: Results strongly suggest that ICG-NIRF imaging system should be used as a routine intraoperative detection method for liver cancer surgery, in order to remove any residual tumor cells and tissue, hence minimizing further risk of remnant tumor regrowth.