Objective: To compare differences in global measures of hepatic metabolism between control subjects and subjects with cirrhosis.
Materials and methods: FDG-PET/CT scans of 33 subjects either without or with cirrhosis were analyzed retrospectively and classified as follows: group 1 includes subjects without cirrhosis or extrahepatic malignancy (1a) (n=11) and subjects without cirrhosis but with history of extrahepatic malignancy (1b) (n=10); group 2 includes subjects with cirrhosis and history of extrahepatic malignancy (n=12). Subjects with focal hepatic lesions, prior hepatic surgery, co-existing liver pathology, or who received chemotherapy or radiation therapy within the last 6 months were excluded. The hepatic volumes, hepatic mean standardized uptake value (SUVmean), and global hepatic glycolysis (GHG) were compared between groups.
Results: Subjects with cirrhosis showed a lower average hepatic SUVmean as compared to non-cirrhotic patients (1.55±0.29 for group 2 versus 1.81±0.23 for group 1; p value=0.009) and lower average values for GHG (2238.29±903.60 for group 2 versus 2974.67±829.16 for group 1; p value=0.024). No differences were noted between the non-cirrhotic subgroups (i.e., between the groups 1a and 1b) without and with associated extrahepatic malignancy, respectively.
Conclusions: We hypothesize that presence of fibrosis, reduction of active inflammation, and decreased hepatic metabolism and function are potential causes of the lower FDG uptake in cirrhotic livers. Our results also indicate that extrahepatic cancer status does not influence FDG uptake in the non-cirrhotic liver in subjects without hepatic metastases.