18F-FDG-PET/CT predicts the distribution of microsatellite lesions in hepatocellular carcinoma

This study was conducted to investigate whether fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) is useful for predicting the distance of intrahepatic metastases and microvascular invasion from the main tumor and the pattern of postoperative recurrence. A total of 89 consecutive patients who underwent 18 F-FDG PET/CT prior to liver resection for hepatocellular carcinoma (HCC) between April, 2006 and December, 2011 were enrolled in this study. The distance between the microsatellite lesion and the main nodule (microsatellite distance) was analyzed and measured pathologically. The correlation between maximal standardized uptake values (SUVmax) and microsatellite distance was analyzed and the independent risk factors for microsatellite distance >1 cm were assessed. The postoperative recurrence patterns were divided into no recurrence, intrahepatic recurrence and extrahepatic recurrence. SUVmax and the distribution of microsatellite lesions were compared among these groups. The postoperative recurrence patterns were also analyzed according to the SUVmax and the microsatellite lesion pattern. SUVmax was found to be significantly correlated with the distance from the microsatellite lesion to the main nodule (r=0.57, P<0.0001). On the multivariate analysis of microsatellite distance >1 cm, the only significant factor was SUVmax [P=0.002; hazard ratio=1.60; 95% confidence interval (CI): 1.23-2.26]. The optimal cutoff value of SUVmax for microsatellite distance >1 cm was 8.8. The mean SUVmax and the microsatellite distance were highest in patients with postoperative extrahepatic metastases (8.6 and 9,160 μm, respectively). In conclusion, the SUVmax of 18 F-FDG PET/CT reflects microsatellite distance and the patterns of postoperative recurrence in HCC. Therefore, 18 F-FDG PET/CT may be a useful imaging modality for determining the resection margin and the treatment protocol for HCC.