e15531 Background: The role of 18F-fluorodeoxyglucose-positron emission tomography (18F FDG- PET) in hepatocelluar carcinoma (HCC) has not been firmly established. We conduct this study to investigate the value of mSUV on 18F FDG-PET as a prognostic factor in HCC, especially in metastatic setting. Methods: We consecutively enrolled HCC patients with extrahepatic metastatic lesions, who have been evaluated with 18F FDG-PET before palliative anticancer treatment, between January 2000 and June 2008 at the Seoul National University Hospital. We retrospectively analyzed the clinical outcome and the value of mSUV as a prognostic factor. Results: A total of 57 patients (male, 86.0%) were enrolled. Median age was 57 years (range, 36–78). Hepatitis B was the predominant cause of HCC (82.5%), followed by non-viral hepatitis (14.0%) and hepatitis C (3.5%). Most patients (94.7%) were Child-Pugh A and 3 patients (5.3%) were Child-Pugh B. The most commonly involved site was lung (47%), bone (26%), and LN (33%). Median serum AFP level was 68ng/ml (range, 2–48000) and the median mSUV was 4.1 (range, 0.5–57.0). Forty patients (70.2%) received systemic chemotherapy, 14 patients (24.6%) received palliative radiotherapy, 23 patients (40.4%) received palliative surgery, and 7 patients (12.3%) received TACE. In univariate analysis of overall survival (OS), patients with mSUV over 4.0, AFP over 400ng/ml, and presence of intrahepatic viable lesion, and no palliative surgery showed significantly shorter OS (p=0.007, p=0.006, p<0.001, p=0.02, respectively). In multivariate analysis of OS, mSUV over 4.0, AFP over 400ng/ml, and presence of intrahepatic viable lesion were independent prognostic factors (p=0.01, p=0.01, p<0.001, respectively). In patients with mSUV > VS <4.0 or AFP > VS <400ng/ml, there was no difference of palliative anticancer treatment pattern. When combined mSUV with AFP, the OS of patients with mSUV >4.0 and AFP>400ng/ml VS mSUV <4.0 or AFP<400ng/ml VS mSUV <4.0 and AFP<400ng/ml was 11.0 months vs 16.0 months vs 35.7 months, respectively (p=0.006). Conclusions: The mSUV on 18F FDG-PET is a prognostic factor for OS in patients with metastatic HCC. The combined analysis of mSUV with AFP can have a more potent prognostic impact. No significant financial relationships to disclose.