Radiological Diagnosis of Pancreatic Neuroendocrine Neoplasms

Neuroendocrine tumors (NETs) pose peculiar problems for imaging techniques in relation to their functional state. In functioning NETs - in which the diagnosis is mainly based on clinical and laboratory findings - the primary imaging “goal” is the localization of the hormonal hypersecretion source/sources; in nonfunctioning NETs – which appear as symptomatic masses or as incidental findings – the priority questions are represented both by the identification and correct histological typing. For all NETs – regardless of their functional state - an accurate staging is also required, as they are often malignant. The basic imaging modality is MDCT for both diagnosis and staging; although MRI is generally superior to CT for liver metastasis detection, the choice between the two methods depends on the local availability and expertise Imaging techniques have an important role also in the follow-up for both diagnosis of recurrent disease and therapy monitoring. In this respect the RECIST criteria, which were designed for general oncology, are less suited; new criteria, which take the special characteristics of NETs into account, are currently under development