title: 131I-6beta-iodomethyl-19-norcholesterol SPECT/CT for primary aldosteronism patients with inconclusive adrenal venous sampling and CT results.
abstract: The 2 main causes of primary aldosteronism (PA) are aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IAH). Dexamethasone-suppression (131)I-6beta-iodomethyl-19-norcholesterol (NP-59) adrenal scintigraphy can assess the functioning of the adrenal cortex. This study evaluated the diagnostic usefulness of NP-59 SPECT/CT in differentiating APA from IAH and in predicting postadrenalectomy clinical outcome for PA patients who had inconclusive adrenal venous sampling (AVS) and CT results.
  
  
  METHODS
  We retrospectively reviewed the 31 adrenal lesions of 27 patients (age range, 33-71 y; mean age +/- SD, 50.4 +/- 10.9 y) who had been clinically confirmed (by saline infusion and captopril tests) to have PA, had inconclusive CT and AVS test results, and had undergone NP-59 imaging before adrenalectomy. The accuracy of NP-59 imaging was determined by comparison with histopathologic findings.
  
  
  RESULTS
  NP-59 SPECT/CT gave us 18 true-positive, 3 false-positive, 6 true-negative, and 4 false-negative results. Compared with planar imaging, SPECT/CT significantly improved diagnostic accuracy and prognostic predicting ability (P = 0.0390 and P = 0.0141, respectively). The NP-59 results were negative for 7 of the 23 patients with unilateral adrenal lesions, and none of these 7 patients had shown postsurgical clinical improvement.
  
  
  CONCLUSIONS
  NP-59 SPECT/CT is an effective imaging tool for differentiating APA from IAH in PA patients whose CT and AVS results are inconclusive. Our results suggest that patients with presurgically negative NP-59 results should be treated medically and that noninvasive NP-59 SPECT/CT may be suited for use as the first lateralization modality after CT in patients with clinically confirmed PA.
authors.affiliation: Department of Nuclear Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. ruohfyen@ntu.edu.tw
authors.forename: Ruoh-Fang
authors.initials: RF
authors.lastname: Yen
authors.forename: Vin-Cent
authors.initials: VC
authors.lastname: Wu
authors.forename: Kao-Lang
authors.initials: KL
authors.lastname: Liu
authors.forename: Mei-Fang
authors.initials: MF
authors.lastname: Cheng
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Wu
authors.forename: Shih-Chieh
authors.initials: SC
authors.lastname: Chueh
authors.forename: Wei-Chou
authors.initials: WC
authors.lastname: Lin
authors.forename: Kwan-Dun
authors.initials: KD
authors.lastname: Wu
authors.forename: Kai-Yuan
authors.initials: KY
authors.lastname: Tzen
authors.forename: Ching-Chu
authors.initials: CC
authors.lastname: Lu
mesh_terms: D015071:19-Iodocholesterol / Q000031:analogs & derivatives*; D000236:Adenoma / Q000150:complications / Q000000981:diagnostic imaging; D000311:Adrenal Glands / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology; D000315:Adrenalectomy; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D006965:Hyperplasia / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014680:Veins
chemical_list: D015071:19-Iodocholesterol; C035501:6-iodomethylcholesterol