Metabolic PET tracers for neuroendocrine tumors

Neuroendocrine tumors originate from the diffuse neuroendocrine system. Embryologically the diffuse neuroendocrine system is derived from the neuoectoderm and the endoderm (gut). The function of diffuse neuroendocrine system cells is to regulate neighbouring cells (paracrine regulation) by the excretion of biologically active amines and hormones. For the production of these hormones, the diffuse neuroendocrine system cells are specialized to be able to take up amino acids precursors and decarboxylate them. This process, also known amino precursor uptake and decarboxylation (APUD), is a common biochemical property of neuroendocrine (tumor-) cells. Neuroendocrine tissues and cells are involved in the regulation of numerous processes within the body and can be found in almost every organ. A large variety of biologically active substances can be produced depending on the required function. Important active pathways are the catecholamine and serotonin pathway.