Neuroendocrine tumors and somatostatin: imaging techniques.
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.
de Herder
W W
WW
Section of Endocrinology, Department of Internal Medicine, Erasmus Rotterdam, the Netherlands. w.w.deherder@erasmusmc.nl
Kwekkeboom
D J
DJ
Valkema
R
R
Feelders
R A
RA
van Aken
M O
MO
Lamberts
S W J
SW
van der Lely
A J
AJ
Krenning
E P
EP
D002276:Carcinoid Tumor / Q000000981:diagnostic imaging; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging; D006801:Humans; D007205:Indium Radioisotopes; D018358:Neuroendocrine Tumors / Q000737:chemistry / Q000000981:diagnostic imaging*; D010235:Paraganglioma / Q000000981:diagnostic imaging; D010673:Pheochromocytoma / Q000000981:diagnostic imaging; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D017481:Receptors, Somatostatin / Q000032:analysis; D013004:Somatostatin / Q000031:analogs & derivatives
D007205:Indium Radioisotopes; D017481:Receptors, Somatostatin; D013004:Somatostatin; C094573:somatostatin receptor 5; C093733:somatostatin receptor 2; C081788:pentetreotide