Prognostic significance of liver CT-attenuation and F-18-FOG uptake for predicting hepatic recurrence following curative resection of colorectal cancer

Objective: This study investigated the predictive values of computed tomography (CT)-attenuation and fluorine-18-fluorodeoxyglucose (F-18-FDG) uptake in the liver for the hepatic recurrence of colorectal cancer. Subjects and Methods:This study retrospectively included 257 colorectal cancer patients who underwent staging F-18-FDG positron emission tomography (PET)/CT and were subsequently treated with curative surgical resection. Using noncontrast-enhanced CT images in PET/CT, the liver-spleen ratio and liver-spleen difference of CT-attenuation and CT-attenuation of the liver were calculated. The maximum and mean F-18-FDG uptake in the liver was measured using the PET images.The relationship of these five liver parameters to recurrence-free survival (RFS), hepatic RFS, and extrahepatic RFS was assessed. Results: In univariate survival analysis, the liver-spleen ratio, liver-spleen difference, and maximum F-18-FDG uptake of the liver were significant predictors of both RFS and hepatic RFS (P<0.05), whereas none of the five liver parameters were significantly associated with extrahepatic RFS (P>0.05). Patients with a low liver-spleen ratio and liverspleen difference and a high maximum F-18-FDG uptake showed better hepatic RFS than those with a high liver-spleen ratio and liver-spleen difference and a low maximum F-18-FDG uptake. In multivariate analysis, the liver-spleen ratio, liver-spleen difference, and maximum F-18-FDG uptake of liver remained significant predictors for hepatic RFS after adjusting for age, sex, obesity, and stage (P<0.05). Conclusions: Computed tomography-attenuation and maximum F-18-FDG uptake in the liver on F-18-FDG PET/CT were significant predictive factors for hepatic RFS in patients with colorectal cancer after curative resection.