IODINE-123-TYR-3-OCTREOTIDE UPTAKE IN PANCREATIC ENDOCRINE TUMORS ANDIN CARCINOIDS IN RELATION TO HORMONAL INHIBITION BY OCTREOTIDE

Uptake of I-123-Tyr-3-octreotide (TOCT) by hormone-secreting abdominal tumors was studied to compare scintigraphic observations with the red uction in hormone levels brought about by a brief therapeutic test. Me thods: A prospective study was conducted on 17 patients, totalizing 46 proven lesions, with endocrine tumors of the pancreas (10 patients, 2 0 lesions) and/or carcinoid metastases (8 patients, 26 lesions). Tumor hormonal hypersecretion was inhibited by octreotide. Results: There w as good agreement between the results of these examinations. Conclusio ns: The detection of abdominal tumors using this radiotracer is strong ly related to its functional characteristics. Variations in the scinti graphic and test results according to different tumor types were in ag reement with published data on the density of somatostatin receptors m easured by in vitro studies or scintigraphy and by the therapeutic eff ects of octreotide.