Problems of diagnostic assessment in advanced pancreatic neuroendocrine neoplasm and treatment implications: a case report and literature review

Abstract

We are reporting a case of a 55-year-old woman who was diagnosed as having a non-functioning pancreatic neuroendocrine neoplasm (NF-PNEN), the World Health Organization (WHO) low grade (G1) with liver metastases. In the staging process the positron emission tomography — computed tomography with Fluorine-18-Fluorodeoxyglucose (F-FDG PET-CT) and spiral CT then the gallium-DOTA-octreotate positron emission tomography — computer tomography (⁶⁸Ga-DOTATATE PET-CT) shown difference in burden of disease. In first line therapy, everolimus (Afinitor^®, Novartis Pharma GmbH, Germany) at the oral dose of 10 mg once daily and octreotide long-acting release (Sandostatin LAR^®) 30 mg i.m. every 4 weeks were administered. Then, due to disease progression — radioisotope therapy with b-emitter Yttrium-90 (⁹⁰Y). Based on this experience and on the review of the literature, we recommend that the discrepancy between the imaging studies could be due to heterogeneity of proliferation rate and somatostatin receptors (SSTR) expression within a primary PNEN and metastases. Therefore in such cases of advanced PNEN WHO G1 in the lack of response to everolimus and octreotide LAR administration isotope therapy without a prior chemotherapy should be considered as a palliative treatment according to ESMO Clinical Practice Guidelines and Polish Network of Neuroendocrine Tumors.