Somatostatin-receptor scintigraphy in Graves' disease: reproducibility and variance of orbital activity.

Somatostatin-receptor (SSTR) scintigraphy using the single photon emission computed tomography (SPECT) technique allows the assessment of orbital inflammation in patients with Graves' disease. Previous studies showed differences in orbital octreotide uptake already 4 hr after injection. In this study, analysis of inter-/intra-observer variance and reproducibility in the evaluation of orbital SPECT images was performed. First, SPECT data of one representative female patient with clinically active Graves' ophthalmopathy (GO), obtained 4 hr after intravenous injection of 110 MBq 111In-pentetreotide and processed by filtered backprojection, were analyzed. Transverse SPECT images were reconstruc…