THE USE OF SOMATOSTATIN RECEPTOR SCINTIGRAPHY IN THE DIFFERENTIAL-DIAGNOSIS OF PANCREATIC DUCT CANCERS AND ISLET-CELL TUMORS

Objective In the present study, the diagnostic value of somatostatin r eceptor scintigraphy (SRS) was evaluated in the preoperative workup in patients with pancreatic duct cancers and islet cell tumors, as well as in the follow-up of these patients. Methods Twenty-six patients wit h suspected primary pancreatic duct cancers and 48 patients with islet cell tumors were studied. The SRS was performed using the radionuclid e-labeled somatostatin analogue In-111-octreotide. Another group of 12 patients who were still alive more than 3 years after pancreaticoduod enectomy for pancreatic duct adenocarcinomas also underwent SRS. Resul ts In 31 (65%) of 48 patients, the primary pancreatic islet cell tumor as well as its often previously not yet recognized metastases could b e visualized. In contrast, none of the 26 pancreatic adenocarcinomas o r their metastases could be seen. In 5 of 12 patients who were alive m ore than 3 years after pancreaticoduodenectomy for pancreatic duct ade nocarcinomas, metastatic lesions were visualized at SRS. In retrospect , these patients were not operated on for adenocarcinomas but for ''no nfunctioning'' islet cell tumors. Conclusions The present study suppor ts the concept that SRS has a place in the preoperative differential d iagnosis of islet cell tumors and pancreatic duct cancers as well as i n the follow-up, especially in those cases in which no tumor histologi c analysis was obtained, or the pathologic examination of the tumor ti ssue had not included special staining procedures for neuroendocrine c haracteristics Our results also indicate that the evaluation of the re sults of investigations on the role of surgery or radiation therapy an d chemotherapy or both in pancreatic duct cancer have to be interprete d with caution, if no histologic analysis and staining for neuroendocr ine characteristics was performed.