title: Detection and Characterization of Parathyroid Adenoma/Hyperplasia for Preoperative Localization: Comparison Between (11)C-Methionine PET/CT and (99m)Tc-Sestamibi Scintigraphy.
abstract: OBJECTIVE
  (11)C-Methionine PET/CT (Met-PET/CT) is a useful imaging method for detection of parathyroid adenoma; however, the reported detection rate has been variable. The current study was intended to investigate detection sensitivity and preoperative localization of parathyroid adenoma (PA) or parathyroid hyperplasia (PH) on Met-PET/CT compared with (99m)Tc-sestamibi (MIBI) scintigraphy in patients with primary hyperparathyroidism (HPT) or suspected PA.
  
  
  METHODS
  Met-PET/CT and MIBI scintigraphy images were reviewed by two nuclear medicine physicians unaware of pathologic results. Detection sensitivities and preoperative localization of detected parathyroid tissues into five predefined segments were evaluated by visual assessment and semi-quantitative analysis with ratio of standardized uptake values (SUVR) between parathyroid tissue and normal lung as reference. Linear regression analysis with SUVR and serum parathyroid hormone (sPTH) was performed for characterization of PA or PH. Predicted PTH (pPTH) was calculated and compared with sPTH in PH and PA. Each pPTH was obtained for a calculated SUVR by using linear regression model from the result of previous linear regression analysis between SUVR and sPTH.
  
  
  RESULTS
  In 16 patients, detection sensitivities of Met-PET/CT and MIBI scintigraphy were 91.7 % (11/12) and 41.7 % (5/12) for PA and PH including both biopsy-confirmed and clinically-suspected cases, and 100 % (8/8) and 50 % (4/8) for pathologically confirmed PA and PH cases only, respectively. Met-PET/CT showed higher performance than MIBI scintigraphy in localization of parathyroid tissues; correct localization rate was 87.5 % (7/8) on Met-PET/CT and 50 % (4/8) on MIBI scintigraphy. In semi-quantitative analysis, SUVR was linearly associated with sPTH by linear regression analysis (sPTH = 39.53 × SUVR - 89.84, p = 0.0383). There was a borderline significant difference in pPTH between PH and PA (35.1 vs 204.7 ± 164.0, p = 0.052), while there was no significant difference in sPTH between PH and PA (289 vs 230.4 ± 160.4, p = 0.305).
  
  
  CONCLUSIONS
  Met-PET/CT has a potential to be a useful diagnostic modality for preoperative detection and localization of parathyroid tissues with higher sensitivity than MIBI scintigraphy, and for characterization of PA or PH.
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 110-744 South Korea.
authors.forename: In Kook
authors.initials: IK
authors.lastname: Chun
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 110-744 South Korea.
authors.forename: Gi Jeong
authors.initials: GJ
authors.lastname: Cheon
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 110-744 South Korea.
authors.forename: Jin Chul
authors.initials: JC
authors.lastname: Paeng
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 110-744 South Korea.
authors.forename: Keon Wook
authors.initials: KW
authors.lastname: Kang
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 110-744 South Korea.
authors.forename: June-Key
authors.initials: JK
authors.lastname: Chung
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 110-744 South Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
keywords: 11C-methionine PET/CT; 99mTc-sestamibi scintigraphy; Parathyroid adenoma; Parathyroid hyperplasia; Preoperative localization; Primary hyperparathyroidism