Relationship Between¹⁸f-fluorodeoxyglucose Uptake And Response To PD-1 Inhibitor Nivalumab In Advanced Hepatocellular Carcinoma

ObjectiveTo evaluate the performance of 18F-fluorodeoxyglucose positron emission tomography(18F-FDGPET)in predicting the therapeutic effect of the anti-programmed death-1(PD-1)inhibitor nivolumab in advanced hepatocellular carcinoma(HCC)based on clinicopathological evidence.MethodThirty-six patients with HCC examined by 18F-FDGPET/CT were enrolled in this cohort study.Immunohistochemical analysis of PD-L1 expression and tumor-infiltrating lymphocytes was performed.In subgroup analysis,sixteen patients both administered nivolumab and examined by 18F-FDGPET/CT were retrospectively evaluated.The lesions' standard uptake values(SUVs)were measured in all patients.ResultsOf the 36 patients who underwent 18F-FDGPET/CT,the degree of tumor FDG uptake was associated with tumor size,differentiation and stage.The amounts of CD68+tumor-associated macrophages(TAM)and CD1b+MDSCs were significantly increased in patients with elevated tumor FDG uptake(SUV?6)compared with those with SUV<6.Meanwhile,there was no significant difference in PD-L1 expression between the two groups.Among the 16 patients,6 individuals with SUV?6 had an objective response rate(ORR)of 83.3%after nivolumab treatment,whereas patients with SUV<6 showed an ORR of 10.0%.ConclusionThe degree of tumor FDG uptake may be related to the therapeutic effect of PD-1 inhibitor in HCC patients.Patients with elevated SUV could obtain superior ORR after nivolumab treatment,which may result from the immunosuppressive state of the tumor microenvironment with no association with PD-L1 expression.