Radionuclide imaging of pancreatic neuroendocrine tumours

Pancreatic neuroendocrine neoplasm (pNEN) prevalence is increasing as a consequence of both the improvement of diagnostic procedures and therapeutic options. Although pNEN is characterised by an overall better prognosis as compared to other forms of solid tumours, the patient outcome can vary greatly. Although conventional imaging procedures (including endoscopic ultrasound, CT and MR) can be employed, imaging of pNEN was completely revolutionised by the introduction of somatostatin receptor imaging (SRI), first by means of scintigraphy followed by PET/CT. In fact, the possibility to non-invasively provide data on somatostatin receptor expression on neuroendocrine tumour (NET) cells has implication not only for diagnosis but also for treatment planning and prognosis. Although SRI plays a central role in the management of pNEN patients, other radiopharmaceuticals (18 F-FDG, 18 F-DOPA and 68Ga-exedin4) have been used and may provide additional data. The present chapter focuses on the various radiopharmaceuticals that have been employed to study pNEN with particular emphasis to those that provide a clear advantage for clinical management.