HIGH-SENSITIVITY OF THE IN-VIVO DETECTION OF SOMATOSTATIN RECEPTORS BY IN-111 (DTPA-OCTREOTIDE)-SCINTIGRAPHY IN MENINGIOMA PATIENTS

The recent availability of isotope-labelled somatostatin analogues has allowed one to detect somatostatin receptors in normal tissue as well as in endocrine or non-endocrine cranial tumours. The purpose of the present study was to establish the value of somatostatin receptor scin tigraphy using an Indium-111-labelled somatostatin analogue, octreotid e, in the diagnostic work-up of meningioma patients. Twenty-two patien ts (16 women, 6 men, aged from 19-70 years) with newly diagnosed, resi dual or recurrent cranial meningiomas were examined. Indium-111-labell ed DTPA-octreotide was injected i.v.. Planar and tomographic images we re obtained with a gamma camera 4-6, and 24 hours after injection. In all of the meningiomas studied a high density of somatostatin receptor s was detected by scintigraphy. No false negative test result was foun d. Due to this, a 100% predictive value of a negative test was calcula ted. However, when the tumours were taken in culture differing stainin g intensity could be seen in the light- and electron microscopic level even on individual cells of a single culture when silver intensified somatostatin-gold was used as ligand. We conclude, that in vivo somato statin receptor scintigraphy may aid in the pre-operative differential diagnosis of skull base tumours.