title: Inter-observer variations in FDG-PET interpretation for cancer screening.
abstract: BACKGROUND
  Diagnostic guidelines for the use of 2-(fluorine 18) fluoro-2 deoxy-D-glucose (FDG)-positron emission tomography (PET) in cancer screening have yet to be established. We assessed inter-observer variability in screening FDG-PET.
  
  
  METHODS
  Subjects comprised 40 individuals who underwent FDG-PET and computed tomography (CT) for cancer screening. To assess various patterns of FDG uptakes, three subsets of the cases were selected: 'Cancer', 15 cases with cancer; 'Not malignant', 15 cases with suspected cancer by FDG-PET who were confirmed as cancer-free; and 'Normal', 10 cases without remarkable FDG uptake who were confirmed as cancer-free. A total of 68 lesions made up of malignancy (n = 18), benign (n = 21), and physiological FDG uptake (n = 29) were interpreted by six physicians. Each observer reviewed each case three times. Step 1 involved interpretation of PET images alone, Step 2 involved side-by-side reading of PET and CT images, and Step 3 involved re-evaluation of findings with the results of other screening tests. We assessed inter-observer agreement for each step.
  
  
  RESULTS
  Inter-observer agreement for all lesions at each step was moderate, compared to fair agreement for 'Normal' subjects. Inter-observer agreement of 'Cancer' and 'Not malignant' subjects in Step 1 were better than those in Step 2 and 3; however, the differences were not statistically significant.
  
  
  CONCLUSIONS
  The interpretation of FDG-PET is adequately reproducible, while that of 'Normal' subjects is less reproducible. Improvement of inter-observer variability in assessing physiological FDG uptakes requires universal reporting criteria in FDG-PET. Correlative interpretation of PET, CT and other information may require standardization in subjects with suspected cancer by FDG-PET.
authors: Department of Radiology, School of Medicine, Yokohama City University, Yokohama, Kanagawa, Japan. akiko225@yokohama-cu.ac.jp
authors: Akiko
authors: A
authors: Suzuki
authors: Yuji
authors: Y
authors: Nakamoto
authors: Takashi
authors: T
authors: Terauchi
authors: Masami
authors: M
authors: Kawamoto
authors: Yoshihiro
authors: Y
authors: Okumura
authors: Yutaka
authors: Y
authors: Suzuki
authors: Toshihiko
authors: T
authors: Sato
authors: Nobukazu
authors: N
authors: Takahashi
authors: Jin
authors: J
authors: Lee
authors: Michio
authors: M
authors: Senda
authors: Kimiichi
authors: K
authors: Uno
authors: Tomio
authors: T
authors: Inoue
mesh_terms: D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis*; D015588:Observer Variation; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18