Prognostic Significance of Volumetric Parameters on Pretreatment FDG PET/CT in Patients With Hepatocellular Carcinoma Receiving Atezolizumab Plus Bevacizumab Therapy

Abstract

Background: This study aimed to assess prognostic significance of FDG PET/CT parameters in predicting progression-free survival (PFS) and overall survival (OS) in patients with hepatocellular carcinoma (HCC) treated with atezolizumab plus bevacizumab therapy.

Patients and methods: We retrospectively enrolled 78 patients with HCC who underwent FDG PET/CT before atezolizumab plus bevacizumab therapy and identified intrahepatic target tumor lesions on pretreatment imaging studies. From PET/CT images, we measured SUVmax, tumor-to-normal liver uptake ratio, metabolic tumor volume, and total lesion glycolysis (TLG) for intrahepatic tumor lesions, as well as SUVmax for extrahepatic metastatic lesions (extrahepatic SUVmax).

Results: In comparisons of PET/CT parameters, patients with progressive disease demonstrated significantly higher TLG values than those achieving complete or partial response ( P < 0.05). In the multivariate survival analysis, TLG independently predicted both PFS ( P = 0.019) and OS ( P = 0.003). Metabolic tumor volume was significantly associated with OS alone ( P = 0.010), and extrahepatic SUVmax was significantly associated with only PFS ( P = 0.045). Patients with high TLG values experienced poorer PFS and OS than those with low TLG values ( P < 0.05).

Conclusions: TLG in intrahepatic HCC lesions was significantly associated with treatment response and served as an independent prognostic factor for PFS and OS. TLG could be a potential imaging biomarker for predicting clinical outcomes in patients with HCC receiving atezolizumab plus bevacizumab therapy.