title: The use of 18F-fluoromethylcholine PET/CT in differentiating focal nodular hyperplasia from hepatocellular adenoma:  a prospective study of diagnostic accuracy.
abstract: BACKGROUND
  Diagnosis of focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) using conventional imaging techniques can be difficult; however, it is important to differentiate between them as these benign liver tumors require different therapeutic strategies. The aim of our study was to prospectively evaluate the use of PET/computed tomography (CT) with F-fluoromethylcholine (F-FCH) as a novel diagnostic approach in the differentiation between HCA and FNH.
  
  
  METHODS
  Fifty-six consecutive patients with a suspicion of one or multiple HCAs or FNHs larger than 2 cm were prospectively included after written informed consent was obtained from them. All the patients underwent a PET/CT with F-FCH. Histopathology of the lesions was the standard of reference. The ratio of the standardized uptake value (SUV) of the lesions compared with normal liver uptake within the same patient was calculated. Statistical tests were evaluated at the 95% confidence interval.
  
  
  RESULTS
  Forty-nine patients with 60 lesions and histopathological diagnosis of FNH or HCA completed the study and were analyzed. The mean SUV ratio for FNH was 1.67±0.31 (mean±SD, n=28), resulting in a positive likelihood ratio of 32.3 for PET-positive FNH. The mean SUV ratio for HCA was 0.82±0.17 (n=32), with a likelihood ratio of ∼100 for PET-negative HCA. Receiver operating characteristic curve analysis revealed an optimal SUV ratio cutoff value of 1.13, which reached 100% sensitivity and 97% specificity in differentiating FNH from HCA.
  
  
  CONCLUSIONS
  This prospective study shows that PET/CT with F-FCH can accurately differentiate FNH from HCA and may become a valuable diagnostic tool when conventional imaging techniques fail to do so.
authors.affiliation: Department of Surgery, Academic Medical Center, The Netherlands. m.bieze@amc.uva.nl
authors.forename: Matthanja
authors.initials: M
authors.lastname: Bieze
authors.forename: Roelof J
authors.initials: RJ
authors.lastname: Bennink
authors.forename: Youssef
authors.initials: Y
authors.lastname: El-Massoudi
authors.forename: Saffire S K S
authors.initials: SS
authors.lastname: Phoa
authors.forename: Joanne
authors.initials: J
authors.lastname: Verheij
authors.forename: Ulrich
authors.initials: U
authors.lastname: Beuers
authors.forename: Thomas M
authors.initials: TM
authors.lastname: van Gulik
mesh_terms: D018248:Adenoma, Liver Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D002794:Choline / Q000031:analogs & derivatives*; D003937:Diagnosis, Differential; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: C516370:fluoromethylcholine; D002794:Choline