Utility of 111Indium-pentetreotide Scintigraphy in Patients with Neuroendocrine Tumors

Neuroendocrine (NE) tumors pose a diagnostic challenge with the need to utilize a combination of biochemical analysis, standard cross-sectional imaging, and more recently, nuclear medicine scans such as (111)indium-pentetreotide scintigraphy (somatostatin receptor scintigraphy, SRS; OctreoScan, Covidien Imaging Solutions, Hazelwood, MO). In this study we sought to evaluate the clinical utility of scintigraphy in the diagnosis and management of patients with NE tumors at a major university hospital. A retrospective chart review was performed on all patients who underwent both (111)indium-pentetreotide scintigraphy and computed tomography/magnetic resonance imaging (CT/MRI) at a single institution between February 2001 and July 2008. Charts were reviewed for patient demographics, symptoms of NE disease, and results of biochemical testing, imaging studies, histopathologic diagnosis, and medical and/or surgical management. One hundred forty-five patients received (111)indium-pentetreotide scintigraphy (SRS) and concurrent cross-sectional imaging (CT/MRI) over the 7-year period studied. In the evaluation of primary disease, 60 % of tumors were localized by anatomic imaging, significantly greater than the 15 % detection rate achieved by SRS. In the evaluation of recurrent disease, 61 % of NE tumors were localized by cross-sectional imaging, significantly greater than the 31 % detection rate of SRS. Scintigraphy identified disease foci not seen on CT/MRI in just 8 of 74 of the cohort with evidence of disease and only altered the surgical management in 3 of 74 cases. Cross-sectional CT/MRI imaging is sufficient for the localization of NE tumors. (111)Indium-pentetreotide scintigraphy does not significantly alter the surgical management of patients with NE tumors, and we suggest that it be selectively reserved for patients with disease that is occult to cross-sectional imaging.