SOMATOSTATIN RECEPTOR SCINTIGRAPHY IN CARCINOIDS, GASTRINOMAS AND GUSHINGS SYNDROME

High numbers of high-affinity somatostatin binding sites have been fou nd on carcinoid tumors, gastrinomas, small cell lung cancers and the m ajority of medullary thyroid cancers, enabling in vivo visualization o f these tumors with octreotide scintigraphy. A comparison of the resul ts obtained at our institution and another 15 centers in Europe show a few remarkable similarities and differences. The overall sensitivity of octreotide receptor scintigraphy to detect the primary GEP tumor an d its metastases is high, e.g. 80-90%. The main difference was found i n gastrinomas and to a lesser extent in insulinomas. These differences might be attributed to different scanning protocols. Furthermore, oct reotide scintigraphy also has a high sensitivity to localize the prima ry tumor and its metastases causing Gushing's syndrome by ectopic prod uction of ACTH or CRH. Octreotide scintigraphy is a new, sensitive and noninvasive technique to localize somatostatin receptor expressing en docrine tumors and their metastases.