A specific imaging technique for gastrointestinal and pancreatic NETs1

As a whole-body imaging technique, Octreoscan is sometimes used instead of CT or MRI for the detection of unsuspected lesions.2,3 The technique is also effective for localizing pancreatic NETs, of which more than 90% express somatostatin receptors.4 The notable exception is insulinomas, which have a lower density of somatostatin receptors,5 but even here, Octreoscan is positive in up to 46% of benign insulinomas.6 The sensitivity of Octreoscan is unaffected by vascularity or secretory activity of tumors.7

Octreoscan requires a radiolabeled contrast agent and specialized imaging equipment1 that may not be available at some centers. Patients are intravenously administered a radiolabeled somatostatin analog (111In-octreotide or 111In-pentetreotide) prior to scintigraphy with a large-field gamma camera.1,2

Octreoscan is a trademark of Covidien AG or one of its affiliates.

1. Balon HR, Goldsmith SJ, Siegel BA, et al. Procedure guideline for somatostatin receptor scintigraphy with 111In-pentetreotide. J Nucl Med. 2001;42(7):1134-1138.
2. Shi W, Johnston CF, Buchanan KD, et al. Localization of neuroendocrine tumours with [111In]DTPA-octreotide scintigraphy (Octreoscan): a comparative study with CT and MR imaging. Q J Med. 1998;91(4):295-301.
3. Gibril F, Jensen RT. Comparative analysis of diagnostic techniques for localization of gastrointestinal neuroendocrine tumors. Yale J Biol Med. 1997;70(2):509-522.
4. Ong SL, Garcea G, Pollard CA, et al. A fuller understanding of pancreatic neuroendocrine tumours combined with aggressive management improves outcome. Pancreatology. 2009;9(5):583-600.
5. Metz DC, Jensen RT. Gastrointestinal neuroendocrine tumors: pancreatic endocrine tumors. Gastroenterology. 2008;135(5):1469-1492.
6. Ehehalt F, Saeger HD, Schmidt CM, Grützmann R. Neuroendocrine tumors of the pancreas. Oncologist. 2009;14(5):456-467.
7. Dromain C, de Baere T, Lumbroso J, et al. Detection of liver metastases from endocrine tumors: a prospective comparison of somatostatin receptor scintigraphy, computed tomography, and magnetic resonance imaging. J Clin Oncol. 2005;23(1):70-78.