title: Prevalence of positive FDG-PET findings in patients with high CEA levels.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the prevalence of positive findings of positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) in patients with high serum CEA levels.
  
  
  METHODS
  A total of 303 patients who had undergone an FDG-PET scan in our institution with high serum CEA levels were analyzed. The prevalence of positive PET findings was evaluated with regard to a previous history of malignancy, absolute value of CEA levels, and the time course of CEA levels (an increasing or decreasing pattern, a change divided by time (DeltaCEA) and doubling time of CEA).
  
  
  RESULTS
  Of 303 patients, 232 were confirmed to have malignancy, and the patient-based sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of PET were 87, 86, 95, 66, and 86%, respectively. There was no statistically significant difference in positive rates according to the history of previous malignancy. The prevalence of PET-positive cases was higher with an increase in absolute CEA levels, and more than 90% of the patients were positive when CEA levels were more than 20 ng/ml. The DeltaCEA was significantly higher and the doubling time was significantly shorter in patients with positive results than those with negative results.
  
  
  CONCLUSIONS
  A high value of serum CEA levels was correlated with a higher prevalence of positive PET findings. FDG-PET scans would be justified in patients with high serum CEA levels, regardless of whether there was or was not a previous history of malignancy.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoinkawahara-cho, Sakyo-Ku, Kyoto 606-8507, Japan. tsug@kuhp.kyoto-u.ac.jp
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Suga
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakamoto
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Saga
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Higashi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hara
authors.forename: Koichi
authors.initials: K
authors.lastname: Ishizu
authors.forename: Hidemitsu
authors.initials: H
authors.lastname: Nishizawa
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000000981:diagnostic imaging / Q000628:therapy; D049268:Positron-Emission Tomography; D012189:Retrospective Studies
chemical_list: D002272:Carcinoembryonic Antigen; D019788:Fluorodeoxyglucose F18