Influence of somatostatin receptor scintigraphy and CT/MRI on the clinical management of patients with gastrointestinal neuroendocrine tumors: an analysis in 188 patients

M. Gotthardt, L. Dirkmorfeld, M. Wied, A. Rinke, M. Béhé, A. Schlieck, H. Höffken, H. Alfke, K. Joseph, K. Klose, T. Behr and R. Arnold

Department of Nuclear Medicine, Philipps University, Marburg, Germany.



Many studies describe the sensitivities and specificities of computed tomography (CT), magnetic resonance imaging (MRI), and somatostatin receptor scintigraphy (SRS) in patients with gastrointestinal neuroendocrine tumors (GNT). We performed a study to evaluate the influence of these techniques on the therapeutic management of patients with advanced stages of GNT.The results of either CT/MRI scans or SRS were reviewed by two independent observers who decided on the therapy of a patient. They then had to determine whether the results of the complementary imaging modality would change the decision. The study design was a matched cross-over study with two groups matching in respect to tumor type, imaging modality known first to the observer, and number of patients. For further analysis, patients were divided into three subgroups dependent on tumor stage (group 1, without metastases, group 2, liver metastases, group 3, recurrent disease/extrahepatic metastases).188 patients were included into the study. If SRS was known to the observers first, CT/MRI changed the therapeutic management in 16.2, 13.9 and 11.4\% of the patients (subgroups 1-3). SRS changed the therapeutic management in 13.5, 12.5 and 10.3\%. Overall, CT/MRI would have changed the management in 13.3\% and SRS in 11.7\% of the patients.Though the patients studied mainly suffered from already advanced stages of the disease, all imaging techniques change the therapeutic management to a comparable extent. Our results support the importance of combined imaging in the management of patients with GNT.