[Neuroendocrine tumors of the stomach, duodenum and pancreas : Value of (hybrid) radiological diagnostics].

CLINICAL/METHODICAL ISSUE: Neuroendocrine tumors (NET) of the stomach, duodenum and pancreas are rare tumors with a low incidence but the exact tumor localization and staging diagnostics are of critical importance for further planning of treatment. STANDARD RADIOLOGICAL
METHODS: Standard primary diagnostic methods include multimodal imaging with computed tomography (CT) and magnetic resonance imaging (MRI) but in 20-50% of the cases the localization of the primary tumor cannot be identified. METHODICAL INNOVATIONS: Modern hybrid imaging procedures combine radiological procedures and functional imaging, e.g. using somatostatin receptor (SSR) positron emission tomography CT (PET)/CT imaging. For the exact diagnostics of the primary tumor and distant metastases morphological and functional aspects can be combined for targeted diagnostics. For primary tumor staging a sensitivity of 80.0% and a specificity of 88.4% are given in the literature. PERFORMANCE: The application of SSR PET/CT led to a change in patient management in 44% of all cases according to a recently published meta-analysis and therefore had a significant influence on the further procedure. ASSESSMENT: The use of SSR PET/CT can provide critical information for further treatment and can lead to a significant change in treatment management in a relevant proportion of patients. PRACTICAL RECOMMENDATIONS: Radiological imaging diagnostics and in particular hybrid functional imaging procedures using PET/CT will become increasingly more relevant for the diagnostics, treatment and follow-up of NET patients.