Phd ceremony Ms. S.J. van Asselt:New imaging strategies in neuroendocrine tumors

Neuroendocrine tumours include rare tumours, originating from (neuro)endocrine cells throughout the body. They occur sporadically, but can also be part of the hereditary tumour syndromes von Hippel-Lindau (VHL) disease and Multiple Endocrine Neoplasia type 1 (MEN1). In both tumour syndromes patients are at high risk to develop pancreatic neuroendocrine tumors. The only curative treatment of neuroendocrine tumours is surgery. Compared to epithelial tumors, neuroendocrine tumours often behave indolent, but can also act more aggressive and/or become resistant to treatment.

Screening is recommended for early detection of pancreatic neuroendocrine tumours in both MEN1 and VHL. In this thesis we compared the new imaging techniques endoscopic ultrasound (EUS) and 11C-5-hydroytryptophan positron emission tomography (11C-5-HTP PET) with the conventional imaging CT or MRI and somatostatin receptor scintigraphy (SRS) for the early detection of pancreatic neuroendocrine tumours in these patients.

There is a need for biomarkers that can predict disease activity or treatment efficacy. Bevacizumab is a monoclonal antibody against vascular endothelial growth factor A (VEGF-A), which is an important growth factor for vascularisation in cancer. Imaging with 89Zr-bevacizumab PET can potentially provide information about VEGF-A status at the tumour site non-invasively. We investigated the role of zirconium -89 (89Zr) labelled bevacizumab as biomarker in PET molecular imaging in VHL disease and in patients with sporadic advanced neuroendocrine tumours treated with everolimus.