Prognostic significance of pretreatment 18F-FDG PET/CT in hepatocellular carcinoma: A systematic review and meta-analysis.

BACKGROUND & AIMS: 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is not routinely recommended for hepatocellular carcinoma (HCC) diagnosis or surveillance, and its prognostic role in patients with HCC remains unclear. This meta-analysis aims to evaluate the prognostic significance of 18F-FDG PET/CT in HCC.

METHODS

A systematic literature search was conducted until August 2024 to identify studies evaluating the prognostic value of 18F-FDG PET/CT in patients with HCC. Studies were included if they reported an association between pre-treatment PET/CT and clinical outcomes, including overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS). A random-effects model was employed with heterogeneity assessed using the I2 statistic.

RESULTS

We identified 59 relevant studies (6 prospective and 53 retrospective) including 8,585 patients. Pre-treatment 18F-FDG PET/CT was positive in 30.8% of patients with HCC. Increased FDG activity was associated with poorer OS (hazard ratio [HR] 2.05, 95% CI 1.77-2.38, I2 = 71.6%), RFS (HR 3.18, 95% CI 2.08-4.86, I2 = 96.8%), and PFS (HR 1.64, 95% CI 1.36-1.98, I2 = 71.8%), respectively. FDG activity was significantly associated with OS for both curative (HR 2.10, 95% CI 1.58-2.80, I2 = 62%) and non-curative (HR 2.28, 95% CI 1.59-3.25, I2 = 75.3%) treatments. The prognostic significance of 18F-FDG PET/CT remained consistent across various PET/CT parameters, including SUVmax, tumor-to-liver ratio, and visual assessment of PET/CT positivity, and curative/non-curative therapeutic modalities, all demonstrating that higher FDG uptake is associated with poorer clinical outcomes.

CONCLUSIONS

Pre-treatment 18F-FDG PET/CT is positive in 30.8% of patients with HCC and is significantly associated with adverse clinical outcomes. These findings support its prognostic relevance in HCC, while further studies may help refine its clinical role and standardize 18F-FDG PET/CT-based risk stratification.

PROSPERO ID: CRD42025633333.

IMPACT AND IMPLICATIONS: This meta-analysis demonstrates that pre-treatment 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has prognostic value in hepatocellular carcinoma (HCC), with higher FDG uptake associated with worse overall, recurrence-free, and progression-free survival. Although not routinely recommended for HCC staging, FDG PET/CT appears to identify a biologically more aggressive subgroup. These findings support its potential role as a complementary tool for risk stratification alongside conventional imaging and clinical markers. Incorporating PET/CT-derived metabolic information may help refine prognostication and guide treatment selection in both curative and non-curative settings. Prospective studies are needed to standardize its use in clinical decision-making.