[Octreotide scintigraphy in thyroid orbitopathy]

Graves' disease, which has an autoimmune basis, is associated with the infiltration of activated lymphocytes into the retrobulbar tissues of the eye. These activated lymphocytes express somatostatin receptors on their surface which mediate the inflammatory response.

To evaluate the efficiency of (111) In-Octreotide scintigraphy in the identification of orbital activity in Graves' disease and the usefulness of treatment with a somatostatin analogue, based on a pre-established protocol within the Nuclear Medicine Department.

We studied a group of eighteen patients with symptomatic Graves' ophthalmopathy of between two months and four years duration. We injected 6 mCi of (111) In-Octreotide parenterally, and performed scintigraphy four and twenty-four hours later. Four patients, all in the active phase, showed orbital somatostatin receptors, for which they were treated with lanreotide 60 mg every fifteen days for three months. Patients were reviewed after 3 months treatment with a further scintigraphy and clinical study.

In our study all four treated patients had less than sixteen months of ophthalmopathy, and three responded well to the treatment.

Scintigraphy with Octreotide is a useful procedure allowing identification of patients in the active phase of the ophthalmopathy who are likely to respond well to treatment with somatostatin analogues.