Objective: This study investigated the predictive values of computed tomography (CT)-attenuation and fluorine-18-fluorodeoxyglucose (18F-FDG) uptake in the liver for the hepatic recurrence of colorectal cancer.
Subject and methods: This study retrospectively included 257 colorectal cancer patients who underwent staging 18F-FDG positron emission tomography (PET)/CT and were subsequently treated with curative surgical resection. Using non contrast-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 18F-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 18F-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 liver-spleen difference and a high maximum 18F-FDG uptake showed better hepatic RFS than those with a high liver-spleen ratio and liver-spleen difference and a low maximum 18F-FDG uptake. In multivariate analysis, the liver-spleen ratio, liver-spleen difference, and maximum 18F-FDG uptake of liver remained significant predictors for hepatic RFS after adjusting for age, sex, obesity, andstage (P<0.05).
Conclusion: Computed tomography-attenuation and maximum 18F-FDG uptake in the liver on 18F-FDG PET/CT were significant predictive factors for hepatic RFS in patients with colorectal cancer after curative resection.