Purpose: This study assessed the prognostic values of volumetric parameters on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in predicting early intrahepatic recurrence-free survival (RFS) after curative resection in patients with hepatocellular carcinoma (HCC).
Methods: A retrospective analysis was performed on 242 patients with HCC who underwent staging FDG PET and subsequent curative surgical resection. The tumor-to-non-tumorous liver uptake ratio, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the HCC lesions on PET were measured. The prognostic values of clinical factors and PET parameters for predicting overall RFS, overall survival (OS), extrahepatic RFS, and early and late intrahepatic RFS were assessed.
Results: The median follow-up period was 54.7 months, during which 110 patients (45.5%) experienced HCC recurrence and 62 (25.6%) died. Patients with extrahepatic and early intrahepatic recurrence showed worse OS than did those with no recurrence or late intrahepatic recurrence (p < 0.001). Serum bilirubin level, MTV, and TLG were independent prognostic factors for overall RFS and OS (p < 0.05). Only MTV and TLG were prognostic for extrahepatic RFS (p < 0.05). Serum alpha-fetoprotein and bilirubin levels, MTV, and TLG were prognostic for early intrahepatic RFS (p < 0.05) and hepatitis C virus (HCV) positivity and serum albumin level were independently prognostic for late intrahepatic RFS (p < 0.05).
Conclusion: Intrahepatic recurrence showed different prognoses according to the time interval of recurrence in which early recurrence had as poor survival as extrahepatic recurrence. MTV and TLG on initial staging PET were significant independent factors for predicting early intrahepatic and extrahepatic RFS in patients with HCC after curative resection. Only HCV positivity and serum albumin level were significant for late intrahepatic RFS, which is mainly attributable to the de novo formation of new primary HCC.
Keywords: FDG PET; Hepatocellular carcinoma; Metabolic tumor volume; Prognosis; Recurrence.