Metastasectomy of Hepatoblastoma Utilizing a Novel Overlay Fluorescence Imaging System

Background: The curability of hepatoblastoma (HB) largely depends on the achievement of radical surgical resection, even for metastatic tumors. However, the extension of the metastatic tumor when viewed through an endoscope with the conventional white-light mode is often unclear. Advancements in imaging technology utilizing indocyanine green (ICG) have facilitated precise resection of metastatic HBs, owing to the longer retention of ICG in such lesions than in other normal tissues. Case: We utilized an endoscope loaded with the PINPOINT system (NOVADAQ Technologies, Inc., Ontario, Canada), which allows for real-time overlay visualization with the same focal range between the white-light mode and near-infrared mode. Metastatic HBs that have taken up ICG are visualized as an area of green color superimposed on a high-definition white-light image. A 19-year-old female who underwent liver transplantation for an unresectable HB 2 years earlier was noted to have metastases on the diaphragm and the pleura. Preoperative magnetic resonance imaging showed metastatic HBs on the right pleura extending from the ribs and the diaphragm. The margin of the metastatic tumor was more sharply demarcated by the PINPOINT system than that detected in the normal white-light mode. The tumor was successfully resected en bloc with real-time guidance utilizing the overlay image. The alphafetoprotein levels were normalized and have remained within normal limits in the 12 months since the operation. Conclusion: Novel overlay imaging technology with ICG makes it possible to achieve real-time precise resection of metastatic HBs.