Somatostatin receptor scintigraphy in neuroendocrine tumors exemplified by a patient with hepatic metastases of gastrinoma

: In a 66-year old woman, who suffered from recurrent melena, diarrhea and hematemesis with multiple untreatable gastric and duodenal ulcers, a markedly increased basal and secretin-stimulated gastrin level, clinically a Zollinger-Ellison syndrome was assumed. The conventional diagnostic procedures (esophago-gastro-duodenoscopy, colonoscopy, endosonography, ERCP, abdominal CT and small bowel enema) had failed to reveal the localisation of any gastrinoma. The thereupon performed scintigraphy with In-111-pentetreotide showed four somatostatin receptor expressing liver lesions: two of them could be detected at first site in the consecutively performed MR scans, another retrospectively bearing in mind the scintigraphic images. Today, the somatostatin receptor imaging seems to be a highly sensitive procedure for detecting and localizing hormonally active gastroenteropancreatic tumors. At the same time it is a method for in vivo evaluation of the somatostatin receptor status of localized GEP tumors, thus delivering a decisive diagnostic step for the evaluation of the effectiveness of a therapy with somatostatin analogues before such an expensive therapy is started.