Role of 18F-FDG PET CT as an independent prognostic indicator in patients with hepatocellular carcinoma

摘要

OBJECTIVES: The aim of the study was to evaluate the role of F-fluorodeoxyglucose PET computed tomography (18F-FDG PET CT) as an independent prognostic indicator in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: PET contrast-enhanced CT scans of 100 consecutive patients with HCC were reviewed retrospectively. Patients were asked to fast for 6 h before the study and blood glucose levels were monitored and ensured to be less than 200 mg/dl before injection of 18F-FDG. After administering the 18F-FDG injection (370-550 MBq) patients were instructed to rest comfortably for 45-60 min. All images were acquired using a dedicated GE Discovery PET/CT scanner. The PET CT scans of all the patients were reported separately by two nuclear medicine physicians. A stage-wise analysis of the compiled data was carried out. Lesions that showed standardized uptake values greater than background activity (activity in adjacent normal liver tissue) were defined as having increased 18F-FDG uptake. Pearson's χ2-test or the Kruskal-Wallis test was used to assess statistical significance. A P value less than 0.05 was taken as significant. RESULTS: In this retrospective study of 100 HCC patients, a radiologically higher-stage disease was found more commonly in patients with 18F-FDG-avid primary tumors (P0.001), whereas a lower-stage disease was found in patients with non-18F-FDG-avid primary tumors. The non-18F-FDG-avid tumors also showed lower incidence of metastatic disease and portal vein thrombosis (P0.001). The histopathological findings of the patients who underwent liver transplantation demonstrated that a higher-grade tumor was more common in the 18F-FDG-avid tumor group than in the non- 18F-FDG-avid tumor group (P0.05). CONCLUSION: An 18F-FDG PET CT scan can be used not only for staging but also as a tool for preoperative prediction of cellular differentiation in patients with HCC. The 18F-FDG uptake seen on a PET scan can serve as a molecular signature for management decisions and can be used as an independent and significant prognostic factor in patients with HCC.