1. Department of Surgery, Faculty of Medicine and Health, Örebro University , 703 62 Örebro , Sweden
2. Second Department of Surgery, “Korgialenio-Benakio,” Red Cross General Hospital , 11526 Athens , Greece
3. Endocrine Oncology Unit, 1st Department of Propaedeutic Internal Medicine, Laiko Hospital, National and Kapodistrian University of Athens , 11527 Athens , Greece
4. Department of Endocrinology and Neuroendocrine Neoplasms, Department of Endocrinology and Pathophysiology, Medical University of Silesia , Katowice 40-055 , Poland
5. ENETS Centre of Excellence, Neuroendocrine Tumor Unit, King's College Hospital , London, SE5 9RS , UK
6. Department of Gastroenterology, King's College Hospital , London, SE5 9RS , UK
7. The ARDEN NET Centre, European Neuroendocrine Tumor Society (ENETS) Centre of Excellence (CoE), University Hospitals Coventry and Warwickshire NHS Trust , Coventry, CV2 DX , UK