title: 11C-methionine PET/CT after inconclusive 99mTc-MIBI-SPECT/CT for localisation of parathyroid adenomas in primary hyperparathyroidism.
abstract: OBJECTIVE
  To investigate the efficacy of PET/CT with 11C-methionine for localizing parathyroid adenomas in patients with suspected primary hyperparathyroidism and inconclusive results of cervical ultrasonography and 99mTc-MIBI-SPECT/CT.
  
  
  METHODS
  Retrospective analysis of imaging data of 18 patients and correlation with clinical outcome, in particular intraoperative findings and histopathology of excised tissue.
  
  
  RESULTS
  12 of 18 patients received surgery. In 10 patients single parathyroid adenomas were found (diameter: 5-20 mm), 2 patients presented parathyroid hyperplasia (5 excised hyperplastic glands (diameter: 2-12 mm). PET/CT correctly localized all adenomas and 1 of 5 hyperplastic glands. The sensitivity per patient was 91.7% (11 of 12), the sensitivity per lesion 73.3% (11 of 15). All lesions missed by PET/CT had a size smaller than 9 mm and a volume of less than 0.2 ml. In 6 patients no surgery was performed. Five of them had a negative or atypical PET/CT. Further follow-up indicated familial hypocalciuric hypercalcemia in 3 of them (thus, PET/CT true negative), in the remaining 2 patients no validation is available. One patient with 2 highly suggestive lesions rejected surgery so far.
  
  
  CONCLUSIONS
  PET/CT with 11C-methionine is a very sensitive method for the detection of parathyroid adenomas, even if they are too small to be visualized by 99mTc-MIBI-SPECT/CT.
authors.forename: U
authors.initials: U
authors.lastname: Braeuning
authors.forename: C
authors.initials: C
authors.lastname: Pfannenberg
authors.forename: B
authors.initials: B
authors.lastname: Gallwitz
authors.forename: R
authors.initials: R
authors.lastname: Teichmann
authors.forename: M
authors.initials: M
authors.lastname: Mueller
authors.forename: H
authors.initials: H
authors.lastname: Dittmann
authors.forename: M
authors.initials: M
authors.lastname: Reimold
authors.affiliation: Prof. Dr. Roland Bares, Department Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, Otfried-Mueller-Str. 14, 72076 Tuebingen, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Bares
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000209:etiology; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008715:Methionine; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D010282:Parathyroid Neoplasms / Q000175:diagnosis* / Q000209:etiology; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; C086242:carbon-11 methionine; D017256:Technetium Tc 99m Sestamibi; D008715:Methionine
keywords: 11C-methionine-PET/CT; 99mTc-MIBI-SPECT/CT; primary hyperparathyreoidism