Neuroendocrine tumors (NET) are rare tumors that require specific diagnosis and treatment. Therefore, this poses a challenge for clinical practice. Diagnosis and treatment can be optimized when physician specialists and other healthcare providers, across various hospitals, join forces to provide patients the best care. Based on this idea, a hospital network called NETwerk was set up. The following hospitals are part of this network: University Hospital Antwerp, VITAZ, AZ Monica, AZ Voorkempen, AZ Klina, Gasthuiszusters Antwerpen, Ziekenhuis Netwerk Antwerpen and AZ Rivierenland. In this NETwerk, patients with a neuroendocrine tumor or patients suspected with a neuroendocrine tumor are discussed with the specialists and treated.The aim of this study is to map the quality of life of NET patients within NETwerk in order to optimize the quality of care. Throughout the diagnosis, the treatment process and the follow-up, the patient will be asked to fill out three questionnaires (QLQ-C30, QLQ-GI.NET21 and a satisfaction survey). These questionnaires will be filled out every six months at home. Patients will be asked to complete these questionnaires over a period of five years.