VALUE OF SOMATOSTATIN RECEPTOR SCINTIGRAPHY - A PROSPECTIVE-STUDY IN GASTRINOMA OF ITS EFFECT ON CLINICAL MANAGEMENT

Background & Aims: Recently [In-111-DTPA-D-Phe(1)]-octreotide was appr oved for somatostatin receptor scintigraphy (SRS) of gastroenteropancr eatic tumors. SRS and other tumor localization methods can be time con suming, expensive, and involve patient inconvenience. The role of SRS in comparison to other tumor localization modalities remains undefined because the relative effects of these methods on management have not been studied. The aim of this study was to determine whether SRS alter s clinical management in Zollinger-Ellison syndrome. Methods: One hund red twenty-two consecutive patients were studied prospectively. Each p atient was assigned to one of five different clinical categories. Conv entional imaging studies (ultrasonography, computerized tomography, ma gnetic resonance image, angiography, and bone scan) were performed, an d the management was proposed. SRS was then performed. Clinical manage ment was reassessed, and whether SRS altered management was determined based on six criteria. Results: SRS was superior to any single imagin g study. SRS altered management in 47% overall and in 22%-60% of patie nts in the five different clinical categories. Primary tumor localizat ion and clarification of equivocal localization results from conventio nal studies were the principal reasons for altering management. SRS wa s equally useful in patients with or without metastatic liver disease. Conclusions: Because of the ability of SRS to alter clinical manageme nt combined with its superior sensitivity, high specificity, simplicit y, and cost-effectiveness, SRS should be the initial imaging modality for patients with gastrinomas.