Somatostatin Receptor Scintigraphy In Ocular Sarcoidosis

Abstract

Purpose: : Sarcoidosis is a multisystemic granulomatous immune mediated inflammatory disorder of unknown etiology. It can affect any organ in various degrees of severity. With somatostatin receptor scintigraphy (SRS) sarcoid granulomas can be visualized because of their overexpression of somatostatin receptors. In this study we investigated the extend of disease in patients with ocular sarcoidosis and correlated scintigraphy patterns with biochemical disease parameters.

Methods: : The localization of sarcoid associated lesions and the degree of intensity of uptake of radionuclide coupled octreotide in 119 patients with ocular sarcoidosis were determined. The degree of intensity was compared with serum angiotensin converting enzyme (ACE) and serum soluble interleukin-2 receptor (sIL-2R). Typical patterns on SRS were compared to conventional chest CT and -X-ray.

Results: : SRS was negative in 7 patients, 1 patient had uptake restricted to the eyes and 101 patients had more sarcoidosis associated lesions.The degree of intensity correlated significantly with ACE (p<0.0001) and sIL-2R levels (p<0.0001). Mediastinal lesions together with either eye, salivary glands, clavicular or hilar localizations on SRS demonstrated a significant characteristic pattern. All patients with abnormal conventional diagnostic investigation were SRS positive. Moreover, of 56 patients with normal radiological findings 27 (48%) expressed pathological SRS uptake. In 19 of these 27 patients a lung biopsy was taken, which confirmed sarcoidosis in 15 patients.

Conclusions: : Ocular sarcoidosis is frequently associated with other localizations of sarcoidosis. The degree of intensity in SRS correlates well with sarcoidosis activity. SRS is more sensitive in diagnosing sarcoidosis localizations, even in patients with normal chest radiology. SRS therefore provides a useful and sensitive imaging technique to determine a site for diagnostic biopsy and, to monitor organ involvement and therapy in patients with sarcoidosis.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • autoimmune disease • imaging/image analysis: clinical