Somatostatin receptor scintigraphy in the diagnosis of neuroendocrine gastroenteropancreatic tumors.

Somatostatin receptor scintigraphy is a new, very sensitive procedure for detecting receptor-positive neuroendocrine tumors. Radiolabeled somatostatin analogues are selectively taken up after intravenous administration by tissue carrying somatostatin receptors and, as with the skeletal scintiscan, permit a whole-body visualization of receptor-positive tumors and metastases. Somatostatin receptor scintigraphy shows an overall sensitivity of about 84% for neuroendocrine gastroenteropancreatic tumors. This kind of scintigraphy should be applied in primary tumor localization, staging, and course control in a confirmed or highly probable neuroendocrine gastroenteropancreatic tumor. Furthermore, the use of a gamma probe for intraoperative tumor localization is demonstrated. Therapy with radioactively marked somatostatin analogues should be possible because of the highly selective tumor uptake. The development of an optimal tracer is the subject of current research.