title: Limited value of 18F-F-DOPA PET to localize pancreatic insulin-secreting tumors in adults with hyperinsulinemic hypoglycemia.
abstract: BACKGROUND
  Fluorine-18-L-dihydroxyphenylalanine positron emission tomography (18F-FDOPA PET) imaging is increasingly used in the workup of neuroendocrine tumors. It has been shown to be an accurate tool in the diagnosis of congenital hyperinsulinism, but limited information is available on its value in adult disease. OBJECTIVE, PATIENTS, AND DESIGN: The objective of this study was to review our experience with 18F-FDOPA PET imaging in six consecutive patients with hyperinsulinemic hypoglycemia (HH) (four solitary insulinomas, one diffuse beta-cell hyperplasia, one malignant insulinoma). 18F-FDOPA uptake was also evaluated in 37 patients (43 procedures) without HH or other pancreatic neuroendocrine tumors, which acted as a control group.
  
  
  RESULTS
  Using visual analysis, 18F-FDOPA-PET proved positive in only one case (a multiple endocrine neoplasia type 1 related insulinoma). In diffuse beta-cell hyperplasia, the pancreatic uptake was similar to controls. In the patient with liver metastases, the extent of disease was underestimated. The pancreatic uptake was not statistically different between controls and hyperinsulinemic patients. The main limitation for identifying insulinomas or beta-cell hyperplasia in adults appears to be to the 18F-FDOPA uptake and retention in the whole pancreas. This drawback is potentially circumvented in focal hyperplasia in newborns due to a lower aromatic amino acid decarboxylase expression in the extralesional pancreatic parenchyma.
  
  
  CONCLUSIONS
  18F-FDOPA PET is of limited value in localizing pancreatic insulin secreting tumors in adult HH. Our results contrast with the referential study and require further analysis.
authors.affiliation: Service Central de Biophysique et de Médecine Nucléaire, Centre Hospitalo-Universitaire Timone, 13385 Marseille Cedex 5, France.
authors.forename: L
authors.initials: L
authors.lastname: Tessonnier
authors.forename: F
authors.initials: F
authors.lastname: Sebag
authors.forename: C
authors.initials: C
authors.lastname: Ghander
authors.forename: C
authors.initials: C
authors.lastname: De Micco
authors.forename: R
authors.initials: R
authors.lastname: Reynaud
authors.forename: F F
authors.initials: FF
authors.lastname: Palazzo
authors.forename: B
authors.initials: B
authors.lastname: Conte-Devolx
authors.forename: J F
authors.initials: JF
authors.lastname: Henry
authors.forename: O
authors.initials: O
authors.lastname: Mundler
authors.forename: D
authors.initials: D
authors.lastname: Taïeb
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D006946:Hyperinsulinism / Q000150:complications* / Q000000981:diagnostic imaging; D007003:Hypoglycemia / Q000150:complications* / Q000000981:diagnostic imaging; D050417:Insulin-Secreting Cells / Q000000981:diagnostic imaging / Q000473:pathology; D007340:Insulinoma / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine