Indocyanine Green Fluorescence Guided Resection of Neuroendocrine Liver Metastases: A Proof-of-Concept Study

Abstract

Introduction: Even though the relative indolent character of neuroendocrine neoplasms, unresected neuroendocrine liver metastases (NELM) have a detrimental impact on survival outcomes. Therefore, complete resection should always be considered if technically possible. The aim of this study was to assess the value of fluorescence guided surgery with indocyanine green (ICG) to resect NELM. Methods: This is a proof-of-concept study including patients who underwent resection of NELM of any grade. Patients who underwent liver resection for other tumour types (colorectal liver metastases, CRLM and hepatocellular carcinoma, HCC) were included to compare ICG uptake. Patients received a bolus infusion of 10 mg ICG approximately 24 hours prior to surgery. Resection of liver metastases were performed using guidance of fluorescence cameras and intra-operative ultrasonography. All resected lesions underwent histopathological assessment by an expert pathologist. Results: Six patients were included in the study: three with NELM, two with CRLM and one with HCC. Five patients underwent a minimally invasive liver resection, and had uptake of ICG in the liver metastases. Uptake of ICG was both homogenous and “rim-shaped” in NELM. A resection was not performed in one patient with NELM, due to unforeseen bilobar metastases. There were no adverse events related to use of ICG fluorescence. All resection margins were negative (R0). Conclusion: This is to our knowledge the first proof-of-concept study describing ICG fluorescence guided resection of NELM. Fluorescence guided resection of NELM using ICG was possible, and uptake of ICG by NELM is comparable to CRLM and HCC.