title: Diagnostic impact of PET with 18F-FDG, 18F-DOPA and 3-O-methyl-6-[18F]fluoro-DOPA in recurrent or metastatic medullary thyroid carcinoma.
abstract: OBJECTIVE
  In patients with medullary thyroid carcinoma (MTC), rising levels of the tumour markers calcitonin and CEA after primary surgery indicate tumour recurrence or metastases. The only chance of cure is the resection of localised tumour tissue. For positron emission tomography (PET) with (18)F-fluorodeoxyglucose ((18)F-FDG) and (18)F-dihydroxyphenylalanine ((18)F-DOPA), sensitivities of 78% and 63% have been reported, but in a considerable percentage of MTC patients the source of tumour marker elevation is not detected. The aim of this retrospective data evaluation was to compare the value of PET with (18)F-FDG, (18)F-DOPA and the amino acid tracer 3-O-methyl-6-[(18)F]fluoro-DOPA ((18)F-OMFD) in the detection of MTC recurrence.
  
  
  METHODS
  Fifteen patients with elevated calcitonin were investigated with PET as part of their individual clinical work-up. All patients underwent (18)F-FDG PET and (18)F-DOPA PET, and ten patients underwent (18)F-OMFD PET.
  
  
  RESULTS
  With (18)F-FDG, seven patients showed foci in the neck, mediastinum, upper abdomen or bone. In seven patients, (18)F-DOPA revealed suspicious foci; five of these seven patients showed partially corresponding uptake of (18)F-FDG in the neck and mediastinum. Two of these patients underwent surgery and metastases were verified. With (18)F-OMFD, a small focus in the liver was suspected in one patient without a correlate on (18)F-FDG PET, (18)F-DOPA PET or conventional imaging.
  
  
  CONCLUSIONS
  (18)F-FDG and (18)F-DOPA showed foci that were highly suspicious for local recurrence or metastasis of MTC, although histological verification in these patients with numerous previous surgical interventions was performed in only two patients. The amino acid tracer (18)F-OMFD had no diagnostic impact in these patients.
authors: Department of Nuclear Medicine, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden and PET-Center Dresden-Rossendorf, Fetscherstrasse 74, 01307 Dresden, Germany. b.beuthien@fz-rossendorf.de
authors: B
authors: B
authors: Beuthien-Baumann
authors: A
authors: A
authors: Strumpf
authors: J
authors: J
authors: Zessin
authors: J
authors: J
authors: Bredow
authors: J
authors: J
authors: Kotzerke
mesh_terms: D000328:Adult; D000368:Aged; D018276:Carcinoma, Medullary / Q000000981:diagnostic imaging* / Q000556:secondary*; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C055151:3-O-methyl-6-fluoro-dopa; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine