Neuroendocrine tumors and somatostatin: imaging techniques

J Endocrinol Invest. 2005;28(11 Suppl International):132-6.


Tumors and metastases bearing the somatostatin receptor subtypes 2 (SSTR2) or SSTR5 can be visualized in vivo after injection of radiolabeled octapeptide somatostatin analogs like 111In-pentetreotide. The sensitivity of 111In-pentetreotide scintigraphy for the detection of carcinoid tumors is 86-95%. The sensitivity of 111In-pentetreotide scintigraphy for the detection of gastrinomas, vasoactive intestinal polypeptide-secreting tumors, and glucagonomas as well as clinically non-functioning lesions is 75-100%. However, for insulinoma this is 50-60%. 111In-pentetreotide scintigraphy generally has a lower detection rate for benign pheochromocytomas than 123I-MIBG scintigraphy, but it can have a complementary role for the staging of malignant pheochromocytomas. It can also be used for the detection of extra-adrenal pheochromocytomas and paragangliomas. Most GH- and TSH-secreting pituitary adenomas can be visualized using 111In-pentetreotide. 111In-pentetreotide scintigraphy is negative in microprolactinomas and ACTH-secreting pituitary microadenomas. 111In-pentetreotide scintigraphy has been successful for the localization of extra-pituitary ACTH-secreting tumors and their metastases, and especially for occult tumors. A large variety of lesions in and around the pituitary region express somatostatin receptors and, therefore, can be visualized by 111In-pentetreotide scintigraphy.

Publication types

  • Review

MeSH terms

  • Carcinoid Tumor / diagnostic imaging
  • Gastrointestinal Neoplasms / diagnostic imaging
  • Humans
  • Indium Radioisotopes
  • Neuroendocrine Tumors / chemistry
  • Neuroendocrine Tumors / diagnostic imaging*
  • Paraganglioma / diagnostic imaging
  • Pheochromocytoma / diagnostic imaging
  • Pituitary Neoplasms / diagnostic imaging
  • Radionuclide Imaging
  • Receptors, Somatostatin / analysis
  • Somatostatin* / analogs & derivatives


  • Indium Radioisotopes
  • Receptors, Somatostatin
  • Somatostatin
  • somatostatin receptor 5
  • somatostatin receptor 2
  • pentetreotide