title: Application of dual phase imaging of 11C-acetate positron emission tomography on differential diagnosis of small hepatic lesions.
abstract: OBJECTIVE
  Previously we observed that dual phase 11C-acetate positron emission tomography (AC-PET) could be employed for differential diagnosis of liver malignancies. In this study, we prospectively evaluated the effect of dual phase AC-PET on differential diagnosis of primary hepatic lesions of 1-3 cm in size.
  
  
  METHODS
  33 patients having primary hepatic lesions with size of 1-3 cm in diameter undertook dual phase AC-PET scans. Procedure included an early upper-abdomen scan immediately after tracer injection and a conventional scan in 11-18 min. The standardized uptake value (SUV) was calculated for tumor (SUVT) and normal tissue (SUVB), from which 11C-acetate uptake ratio (as lesion against normal liver tissue, SUVT/SUVB) in early imaging (R1), conventional imaging (R2), and variance between R2 and R1 (ΔR) were derived. Diagnoses based on AC-PET data and histology were compared. Statistical analysis was performed with SPSS 19.0.
  
  
  RESULTS
  20 patients were found to have HCC and 13 patients had benign tumors. Using ΔR>0 as criterion for malignancy, the accuracy and specificity were significantly increased comparing with conventional method. The area under ROC curve (AUC) for R1, R2, and ΔR were 0.417, 0.683 and 0.831 respectively. Differential diagnosis between well-differentiated HCCs and benign lesions of FNHs and hemangiomas achieved 100% correct. Strong positive correlation was also found between R1 and R2 in HCC (r2 = 0.55, P<0.001).
  
  
  CONCLUSIONS
  Dual phase AC-PET scan is a useful procedure for differential diagnosis of well-differentiated hepatocellular carcinoma and benign lesions. The dynamic changes of 11C-acetate uptake in dual phase imaging provided key information for final diagnosis.
authors.affiliation: Department of Nuclear Medicine, PET Center, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Huo
authors.affiliation: Department of Nuclear Medicine, PET Center, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Dang
authors.affiliation: Department of Nuclear Medicine, PET Center, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Jingqiao
authors.initials: J
authors.lastname: Lv
authors.affiliation: Department of Nuclear Medicine, PET Center, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Haiqun
authors.initials: H
authors.lastname: Xing
authors.affiliation: Department of Nuclear Medicine, PET Center, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
mesh_terms: D000085:Acetates; D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D012372:ROC Curve; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results
chemical_list: D000085:Acetates; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals