Objective: To conduct a meta-analysis of the diagnostic efficacy of fluorine-18-fluorodeoxyglucose (18F-FDG) and gallium-68-labeled fibroblast-activation protein inhibitor (68Ga-FAPI) positron emission tomography/computed tomography (PET/CT) for primary liver cancer based on existing clinical evidence.
Materials and methods: Meta-analysis was carried out according to PRISMA reporting specification. The clinical studies in PubMed/Medline, Embase and the Cochrane Library database were retrieved from the establishment to September 2022. Two researchers independently conducted literature screening and data extraction, evaluated the risk of bias according to QUADAS-2, conducted meta-analysis using Meta Disc 1.4 and Stata15.1 software, and calculated the summarized sensitivity (SEN), specificity (SPE), positive likelihood ratio (+LR), negative likelihood ratio (-LR), and diagnostic odds ratio (DOR). The diagnostic performance of 18F-FDG PET/CT and 68Ga-FAPI PET/CT for primary liver cancer was compared using summarized receiver operating characteristic (SROC) curve and area under curve (AUC).
Results: Four original studies on 18F-FDG PET/CT and 68Ga-FAPI PET/CT in the diagnosis of primary liver cancer were included, including 159 intrahepatic lesions in 106 patients. Taking lesions as a unit, in four original studies, the pooled results of 18F-FDG PET/CT diagnosis of primary liver cancer were Sen=0.5 (95% CI:95% CI: 0.41-0.59), Spe=0.87 (95% CI: 0.52-0.98), AUC=0.58 (95% CI:0.53-0.62); The pooled results of 68Ga-FAPI PET/CT in the diagnosis of primary liver cancer, Sen=0.5 (95% CI: 0.41-0.59), Spe=0.87 (95%CI:0.52-0.98), AUC=0.58 (95% CI:0.53-0.62). Besides, the Sen of 68Ga-FAPI PET/CT in the diagnosis of primary liver cancer was higher than that of 18F-FDG PET/CT (Z=2.323, P=0.02), the difference was statistically significant.
Conclusion: Gallium-68-FAPI PET/CT is a promising tool. Compared with 18F-FDG, 68Ga-FAPI has higher sensitivity to detect more lesions in primary liver cancer and metastatic lesions, and has high performance in the diagnosis of primary liver cancer.