title: 99mTc(V)-DMSA SPECT for the assessment of disease activity in Graves' ophthalmopathy.
abstract: OBJECTIVE
  The aim of this study was to evaluate the use of 99mTc(V)-dimercaptosuccinic acid (99mTc(V)-DMSA) scintigraphy for the assessment of disease activity in patients with Graves' ophthalmopathy (GO) and compare their clinical parameters.
  
  
  METHODS
  The study involved 20 patients who were clinically inactive and eight patients who were clinically active, a total 28 GO patients (18 female, 10 male; mean age: 39.2+/-13.4 years) and 12 control subjects (six female, six male; mean age: 57.12+/-12 years). Planar and SPECT orbital images were obtained 4 h after the intravenous injection of 555-740 MBq 99mTc(V)-DMSA, using low-energy, high-resolution, parallel-hole collimators with dual-head detectors. All SPECT data were reconstructed on conventional axial, sagittal and coronal projections using an iterative reconstruction. Semi-quantitative evaluation was performed comparing the orbital activity with nasal activity based on four grades. GO was classified according to the NOSPECS classification of the American Thyroid Association. Disease was considered clinically active if symptoms and signs deteriorated over 3 months.
  
  
  RESULTS
  No significant correlation was detected between clinical activity and classification (P=0.192). However, clinical activity and 99mTc(V)-DMSA uptake were significantly correlated (P=0.0001). There was no correlation between the clinical classification and scintigraphic grading. Bilateral orbital index of the active group was significantly higher than that of the inactive group (P=0.0001).
  
  
  CONCLUSIONS
  99mTc(V)-DMSA imaging discriminates the active from inactive GO as well as showing an ongoing subclinical inflammation in the orbits of the patients with GO, regardless of the disease activity clinically. Our results revealed that 99mTc(V)-DMSA is a promising agent for the diagnosis of active Graves' ophthalmopathy.
authors.affiliation: Department of Nuclear Medicine, Baskent University Faculty of Medicine, Ankara, Turkey. drmreyhan@yahoo.com.tr
authors.forename: Mehmet
authors.initials: M
authors.lastname: Reyhan
authors.forename: Okan
authors.initials: O
authors.lastname: Toygar
authors.forename: Aysun
authors.initials: A
authors.lastname: Sukan
authors.forename: Gulsah
authors.initials: G
authors.lastname: Seydaoglu
authors.forename: Okan S
authors.initials: OS
authors.lastname: Bakiner
authors.forename: Mehmet
authors.initials: M
authors.lastname: Aydin
authors.forename: A Fuat
authors.initials: AF
authors.lastname: Yapar
authors.forename: Ayse
authors.initials: A
authors.lastname: Aktas
mesh_terms: D000328:Adult; D005260:Female; D049970:Graves Ophthalmopathy / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid