title: FDG-Avid Portal Vein Tumor Thrombosis from Hepatocellular Carcinoma in Contrast-Enhanced FDG PET/CT.
abstract: OBJECTIVE
  In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT), complicating hepatocellular carcinoma (HCC) in contrast-enhanced FDG PET/CT scan.
  
  
  METHODS
  In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis.
  
  
  RESULTS
  Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%). PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8 ± 0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001). FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001). PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6%) had no extrahepatic metastasis, 3 cases (33.3%) had metastasis of regional lymph nodes, and 1 case (11.1%) presented with distant metastasis. The median estimated survival time of patients was 5 months.
  
  
  CONCLUSIONS
  The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are findings of FDG-avid PVTT from HCC in contrast-enhanced FDG PET/CT.
authors.affiliation: Unit of PET/CT and Cyclotron, Choray Hospital, Vietnam.
authors.forename: Xuan Canh
authors.initials: XC
authors.lastname: Nguyen
authors.affiliation: Department of Liver Tumor, Choray Hospital, Vietnam.
authors.forename: Dinh Song Huy
authors.initials: DS
authors.lastname: Nguyen
authors.affiliation: Unit of PET/CT and Cyclotron, Choray Hospital, Vietnam.
authors.forename: Van Tan
authors.initials: VT
authors.lastname: Ngo
authors.affiliation: Dipartimento Di Scienze Biomediche Avanzate, Facoltá Di Medicina E Chirurgia, Università Degli Studi Di Napoli Federico II, Italia.
authors.forename: Simone
authors.initials: S
authors.lastname: Maurea
keywords: FDG; Hepatocellular carcinoma (HCC); PET/CT; Portal vein tumor thrombosis (PVTT)