title: 11C-methionine PET/CT imaging of 99mTc-MIBI-SPECT/CT-negative patients with primary hyperparathyroidism and previous neck surgery.
abstract: BACKGROUND
  (99m)Tc-Methoxy-isobutyl-isonitrile (MIBI) scintigraphy is a standard preoperative localization imaging modality in patients with primary hyperparathyroidism (pHPT). Its accuracy in localizing a hyperactive parathyroid gland after previous cervical surgery is limited. Recently, (11)C-methionine has been introduced as a promising radiotracer for pHPT imaging. Yet, few data exist for this technique in patients with persisting or recurrent pHPT before reoperation.
  
  
  OBJECTIVE
  We aimed to investigate the ability of (11)C-methionine positron emission tomography (PET)/computed tomography (CT) to localize a parathyroid disorder after cervical surgery and negative postsurgical (99m)Tc-MIBI single-photon emission CT (SPECT)/CT.
  
  
  METHODS
  Fifteen patients (6 males, 9 females; age range, 36-85 years) with pHPT and negative (99m)Tc-MIBI SPECT/CT who had undergone earlier neck surgery because of pHPT and/or thyroid disorder were recruited. Twelve of the 15 patients had thyroidectomy for goiter or differentiated thyroid carcinoma. Ten patients had previous parathyroid surgery for pHPT, and 2 patients had a history of parathyroid carcinoma. Thirteen of 15 patients showed elevated levels of intact PTH at the time of PET/CT imaging, whereas all patients had elevated serum calcium values.
  
  
  METHODS
  Pathological results of contrast-enhanced (11)C-methionine PET/CT and surgical results were evaluated.
  
  
  RESULTS
  In 6 of 15 patients (11)C-methionine PET/CT showed a hypermetabolic focus in the upper mediastinum in 2 patients, in the thoracic outlet in 1 patient, and in the cervical region in 3 patients. In 9 of the 15 patients, no hyperactive parathyroid gland could be visualized. Reoperation was performed in 5 of 6 patients without surgical complications. One patient refused surgery. In 2 of the 5 patients, a transsternal procedure was performed. Correlating with the (11)C-methionine PET/CT results, a single parathyroid adenoma was found in 4 patients and parathyroid carcinoma metastasis in 1 patient.
  
  
  CONCLUSIONS
  (11)C-Methionine PET/CT is a useful complementary imaging technique to localize parathyroid adenoma or carcinoma in (99m)Tc-MIBI SPECT/CT-negative patients.
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Divisions of Nuclear Medicine (T.T.-W., M.M., H.D., G.K., M.H.) and Radiology (M.E.M.), and Departments of Clinical Pathology (O.K.) and Surgery (B.N.), Section of Endocrine Surgery, Medical University of Vienna, 10190 Vienna, Austria.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Traub-Weidinger
authors.forename: Marius E
authors.initials: ME
authors.lastname: Mayerhoefer
authors.forename: Oskar
authors.initials: O
authors.lastname: Koperek
authors.forename: Markus
authors.initials: M
authors.lastname: Mitterhauser
authors.forename: Heying
authors.initials: H
authors.lastname: Duan
authors.forename: Georgios
authors.initials: G
authors.lastname: Karanikas
authors.forename: Bruno
authors.initials: B
authors.lastname: Niederle
authors.forename: Martha
authors.initials: M
authors.lastname: Hoffmann
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000000981:diagnostic imaging / Q000601:surgery; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D013965:Thyroidectomy; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi