title: Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography as a tool to localize an insulinoma or beta-cell hyperplasia in adult patients.
abstract: OBJECTIVE
  Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) is a promising method in localizing neuroendocrine tumors. Recently, it has been shown to differentiate focal forms of congenital hyperinsulinism of infancy. The current study was set up to determine the potential of 18F-DOPA PET in identifying the insulin-secreting tumors or beta-cell hyperplasia of the pancreas in adults.
  
  
  METHODS
  We prospectively studied 10 patients with confirmed hyperinsulinemic hypoglycemia and presumed insulin-secreting tumor using 18F-DOPA PET. Anatomical imaging was performed with computed tomography (CT) and magnetic resonance imaging (MRI). All patients were operated on, and histological verification was available in each case. Semiquantitative PET findings in the pancreas using standardized uptake values were compared to standardized uptake values of seven consecutive patients with nonpancreatic neuroendocrine tumors.
  
  
  RESULTS
  By visual inspection of 18F-DOPA PET images, it was possible in nine of 10 patients to localize the pancreatic lesion, subsequently confirmed by histological analysis. 18F-DOPA uptake was enhanced in six of seven solid insulinomas and in the malignant insulinoma and its hepatic metastasis. Two patients with beta-cell hyperplasia showed increased focal uptake of 18F-DOPA in the affected areas. As compared to CT or MRI, 18F-DOPA PET was more sensitive in localizing diseased pancreatic tissue.
  
  
  CONCLUSIONS
  18F-DOPA PET was useful in most patients with insulinoma and negative CT, MRI, and ultrasound results. In agreement with previous findings in infants, preoperative 18F-DOPA imaging seems to be a method of choice for the detection of beta-cell hyperplasia in adults. It should be considered for the detection of insulinoma or beta-cell hyperplasia in patients with confirmed hyperinsulinemic hypoglycemias when other diagnostic work-up is negative.
authors.affiliation: Turku PET Centre, Department of Surgery, Turku University Hospital, P.O. Box 52, FIN-20521 Turku, Finland.
authors.forename: Saila
authors.initials: S
authors.lastname: Kauhanen
authors.forename: Marko
authors.initials: M
authors.lastname: Seppänen
authors.forename: Heikki
authors.initials: H
authors.lastname: Minn
authors.forename: Risto
authors.initials: R
authors.lastname: Gullichsen
authors.forename: Anna
authors.initials: A
authors.lastname: Salonen
authors.forename: Kalle
authors.initials: K
authors.lastname: Alanen
authors.forename: Riitta
authors.initials: R
authors.lastname: Parkkola
authors.forename: Olof
authors.initials: O
authors.lastname: Solin
authors.forename: Jörgen
authors.initials: J
authors.lastname: Bergman
authors.forename: Timo
authors.initials: T
authors.lastname: Sane
authors.forename: Jorma
authors.initials: J
authors.lastname: Salmi
authors.forename: Matti
authors.initials: M
authors.lastname: Välimäki
authors.forename: Pirjo
authors.initials: P
authors.lastname: Nuutila
mesh_terms: D000328:Adult; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D006965:Hyperplasia; D050417:Insulin-Secreting Cells / Q000000981:diagnostic imaging*; D007340:Insulinoma / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; C029112:5-fluorodopa; D004295:Dihydroxyphenylalanine