title: Role of 18F-fluorodeoxyglucose positron emission tomography in detecting extrahepatic metastasis in pretreatment staging of hepatocellular carcinoma.
abstract: OBJECTIVE
  18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is useful for differentiating benign from malignant lesions, evaluating tumor stage, monitoring the response to therapy and detecting tumor recurrence in a variety of malignancies. Nevertheless, its use in patients with hepatocellular carcinoma (HCC) is still uncertain. We evaluated whether FDG-PET has a role in detecting extrahepatic metastasis in pretreatment tumor staging of HCC and the characteristics of patients with extrahepatic metastasis that benefit from FDG-PET.
  
  
  METHODS
  Eighty-seven patients with HCC underwent computed tomography (CT) or magnetic resonance imaging (MRI) of the abdomen and chest X-ray to evaluate pretreatment tumor staging. FDG-PET was then performed to detect extrahepatic metastasis. The power of FDG-PET to detect extrahepatic metastasis was compared with that of conventional images. In addition, we evaluated whether the detection of extrahepatic metastasis using FDG-PET changed the TNM stage. Moreover, we investigated the clinical and tumor characteristics of patients with extrahepatic HCC metastasis.
  
  
  RESULTS
  Extrahepatic metastases were identified in 24 of 87 patients. The location and frequency of metastases were lung 12, lymph nodes 19 and bone 11. All of the extrahepatic metastases were detected by FDG-PET. In addition, FDG-PET identified 4 lymph node metastases and 6 bone metastases that were not found using conventional methods. The initial TNM stage based on the conventional staging workup was changed in 4 cases after FDG-PET. Extrahepatic metastasis was significantly more frequent in patients with intrahepatic tumor >5 cm in size (p = 0.045).
  
  
  CONCLUSIONS
  FDG-PET is a useful imaging modality for identifying extrahepatic metastases which may lead to accurate staging and proper management of patients with possible extrahepatic metastases.
authors: Department of Internal Medicine, Yonsei University College of Medicine, Yonsei Liver Cancer Special Clinic, Severance Hospital, Seoul, Korea.
authors: Ki Tae
authors: KT
authors: Yoon
authors: Ja Kyung
authors: JK
authors: Kim
authors: Do Young
authors: DY
authors: Kim
authors: Sang Hoon
authors: SH
authors: Ahn
authors: Jong Doo
authors: JD
authors: Lee
authors: Mijin
authors: M
authors: Yun
authors: Sun Young
authors: SY
authors: Rha
authors: Chae Yoon
authors: CY
authors: Chon
authors: Kwang-Hyub
authors: KH
authors: Han
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000556:secondary*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18