title: Accuracy of Dual Phase Single-Photon Emission Computed Tomography/Computed Tomography in Primary Hyperparathyroidism: Correlation With Serum Parathyroid Hormone Levels.
abstract: OBJECTIVE
  The objectives of this study were: 1) to determine the accuracy of dual-phase (99m)Tc -methoxyisobutylisonitrile (MIBI) with single-photon emission computed tomography/computed tomography (SPECT/CT) for the preoperative localization of parathyroid adenomas in the setting of primary hyperparathyroidism; 2) to determine the accuracy of localization for ectopic glands; and 3) to assess the relationship between accuracy and serum parathyroid hormone (PTH) levels.
  
  
  METHODS
  Eighty-eight patients who underwent (99m)Tc-MIBI SPECT/CT imaging for primary hyperparathyroidism at our institution over a 27-month period were retrospectively assessed. The preoperative SPECT/CT results were compared to intraoperative findings (within 1 year of imaging). The relationship between serum PTH level (within 3 months) and SPECT/CT accuracy was then evaluated.
  
  
  RESULTS
  Accuracy indices for the retrothyroid subgroup were sensitivity 86.7%, specificity 96.4%, positive predictive value 98.1%, negative predictive value 77.1%, and accuracy 89.8%. Accuracy indices for ectopic parathyroid adenomas were sensitivity 81.5%, specificity 100%, positive predictive value 100%, negative predictive value 92.4%, and accuracy 94.3%. For the overall group, SPECT/CT demonstrated a sensitivity of 85.1% and a PPV of 98.7%. SPECT/CT correctly identified the abnormal parathyroid gland in 60% of patients with a normal serum PTH (<6.9 pmol/L), 73% between 6.9-9.9 pmol/L, 86% between 10.0-14.9 pmol/L, 100% between 15.0-19.9 pmol/L, 88% between 20.0-24.5 pmol/L, and 100% of patients with a PTH greater than 25.0 pmol/L.
  
  
  CONCLUSIONS
  Dual-phase (99m)Tc- MIBI with SPECT/CT is an accurate and reliable means to correctly localize both retrothyroid and ectopic parathyroid adenomas for the purpose of surgical planning. The accuracy of SPECT/CT increases with increasing serum PTH levels.
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Wade
authors.initials: W
authors.lastname: Koberstein
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Fung
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Kristy
authors.initials: K
authors.lastname: Romaniuk
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada. Electronic address: jabele@ualberta.ca.
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Abele
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000000981:diagnostic imaging; D010281:Parathyroid Hormone / Q000097:blood*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000072098:Single Photon Emission Computed Tomography Computed Tomography; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone
keywords: (99m)Tc-methoxyisobutylisonitrile; Parathyroid adenoma; Parathyroid hormone; Primary hyperparathyroidism; Single-photon emission computed tomography/computed tomography