title: Incidental diagnosis of tumor thrombosis on FDG PET/CT imaging.
abstract: OBJECTIVE
  Clinical data are presented on patients with tumor thrombosis (TT) incidentally detected on FDG PET/CT imaging, as well as determining its prevalence and metabolic characteristics.
  
  
  METHODS
  Out of 12,500 consecutive PET/CT examinations of patients with malignancy, the PET/CT images of 15 patients with TT as an incidental finding were retrospectively investigated. A visual and semiquantitative analyses was performed on the PET/CT scans. An evaluation was made of the pattern of FDG uptake in the involved vessel as linear or focal via visual analyses. For the semiquantitative analyses, the metabolic activity was measured using SUVmax by drawing the region of interest at the site of the thrombosis and tumor (if any).
  
  
  RESULTS
  The prevalence of occult TT was 0.12%. A total of 15 patients had various malignancies including renal (1 patient), liver (4), pancreas (2), stomach (1), colon (1), non-Hodgkin lymphoma (1), leiomyosarcoma (1), endometrial (1), ovarian (1), malign melanoma (1) and parotid (1). Nineteen vessels with TT were identified in 15 patients; three patients had more than one vessel. Various vessels were affected; the most common was the inferior vena cava (n=7) followed by the portal (n=5), renal (n=3), splenic (n=1), jugular (n=1), common iliac (n=1) and ovarian vein (n=1). The FDG uptake pattern was linear in 12 and focal in 3 patients. The mean SUVmax values in the TT and primary tumors were 8.40±4.56 and 13.77±6.80, respectively.
  
  
  CONCLUSIONS
  Occult TT from various malignancies and locations was found incidentally in 0.12% of patients. Interesting cases with malign melanoma and parotid carcinoma and with TT in ovarian vein were first described by FDG PET/CT. Based on the linear FDG uptake pattern and high SUVmax value, PET/CT may accurately detect occult TT, help with the assessment of treatment response, contribute to correct tumor staging, and provide additional information on the survival rates of oncology patients.
authors.affiliation: Department of NuclearMedicine, Faculty of Medicine, BaskentUniversity, Turkey. Electronic address: sevaler@yahoo.com.
authors.forename: S
authors.initials: S
authors.lastname: Erhamamci
authors.affiliation: Department of NuclearMedicine, Faculty of Medicine, BaskentUniversity, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Reyhan
authors.affiliation: Department of NuclearMedicine, Faculty of Medicine, BaskentUniversity, Turkey.
authors.forename: G N
authors.initials: GN
authors.lastname: Nursal
authors.affiliation: Department of NuclearMedicine, Faculty of Medicine, BaskentUniversity, Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Torun
authors.affiliation: Department of NuclearMedicine, Faculty of Medicine, BaskentUniversity, Turkey.
authors.forename: A F
authors.initials: AF
authors.lastname: Yapar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D009360:Neoplastic Cells, Circulating; D000072078:Positron Emission Tomography Computed Tomography; D015995:Prevalence; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D013927:Thrombosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D054556:Venous Thromboembolism / Q000175:diagnosis; D055815:Young Adult
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: FDG; PET/CT; PET/TC; SUVmax; Trombosis tumoral; Tumor thrombosis