Functional Liver Imaging Score as a Prognostic Factor After Hepatectomy for Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

Background: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, and hepatic resection remains a primary curative treatment. Accurate preoperative assessment of the functional reserve of the future liver remnant is critical for predicting post-hepatectomy liver failure (PHLF) and long-term survival. Conventional tools such as the Model for End-Stage Liver Disease (MELD), albumin-bilirubin (ALBI) grade, and indocyanine green retention rate at 15 minutes (ICG-R15) have known limitations. The Functional Liver Imaging Score (FLIS), a semiquantitative scoring system ranging from 0 to 6 based on three parameters assessed on gadoxetic acid-enhanced MRI (hepatic enhancement, biliary contrast excretion, and portal vein signal intensity), provides a non-invasive assessment of regional hepatocyte function. While individual studies have reported associations between FLIS and outcomes after hepatectomy for HCC, these have been conducted in heterogeneous populations with varying outcome definitions, and no systematic synthesis of this evidence exists. Objectives: To systematically evaluate the prognostic value of FLIS for clinically relevant outcomes after hepatectomy for HCC, including: (1) post-hepatectomy liver failure (PHLF); (2) overall survival (OS); and (3) discriminative performance compared with conventional liver function assessment tools. Methods: PubMed/MEDLINE, Embase, Web of Science Core Collection, Scopus, and the Cochrane Library were searched from database inception to January 31, 2026. Studies were eligible if they included adult patients (≥18 years) with HCC undergoing hepatic resection with curative intent, with preoperative FLIS assessed on gadoxetic acid-enhanced MRI. Risk of bias was assessed using the Quality In Prognosis Studies (QUIPS) tool. DerSimonian-Laird random-effects meta-analyses were performed for three outcomes: pooled odds ratios for PHLF per one-point FLIS increase, pooled hazard ratios for OS (low vs. high FLIS), and pooled AUC for discriminative ability. Heterogeneity was quantified using the I² statistic. The review was conducted following PRISMA 2020 reporting guidelines. Expected outcomes: This review will provide the first comprehensive synthesis of evidence on FLIS as a prognostic biomarker after hepatectomy for HCC, informing clinical decision-making regarding preoperative functional liver assessment with gadoxetic acid-enhanced MRI.