Determination of surgical margins in laparoscopic parenchyma-sparing hepatectomy of neuroendocrine tumors liver metastases using indocyanine green fluorescence imaging

Background Neuroendocrine tumors (NETs) are a group of heterogenous tumors originating from neuroendocrine system. Approximately, 40 percent will go through liver metastases, and liver-directed therapy was proved to improve the survival outcome. Parenchyma-sparing hepatectomy is advocated for the resection of NETs liver metastases while the possible relatively low negative margin rate is concerned. Indocyanine green (ICG) fluorescence imaging provides a real-time navigation on determination of surgical margins in colorectal cancer liver metastases. However, there was no previous study that reported the applications of ICG fluorescence imaging in NETs liver metastases. The present study aimed to evaluate the feasibility and security of using ICG fluorescence imaging to determine surgical margins of NETs liver metastases during operation. Methods A retrospective two-arm cohort study was performed on 25 consecutive patients with NETs liver metastases who underwent laparoscopic parenchyma-sparing hepatectomy (LPSH). Patients were divided into two groups according to whether or not the ICG fluorescence imaging was used. Data on sociodemographic characteristics, laboratory parameters, pathology results, and surgical outcomes were collected. Results A total of 145 tumors pathologically diagnosed with NETs liver metastases were resected from 25 patients. The pathological results indicated negative margins in all tumors (102/102) in LPSH with ICG fluorescence imaging group. The negative margin rate was significantly higher in LPSH using the ICG fluorescence imaging (100% v.s 88.4%, p = 0.002). Surgical outcomes, including operation time, estimated blood loss, intraoperative transfusion rate, and postoperative morbidity, were comparable between LPSH with and without ICG fluorescence imaging groups. Conclusion ICG fluorescence imaging showed the potential to identify tumor boundaries and determine surgical margins. This technique may serve as a valuable intraoperative navigation in patients with NETs liver metastases.