1. Department of Hygiene, Epidemiology, and Medical Statistics, School of Medicine; National and Kapodistrian University of Athens; Athens Greece
2. Department of Neurology; University Hospital; Linköping Sweden
3. National Cancer Registry of Ukraine; National Institute of Cancer; Kiev Ukraine
4. Institute of Public Health of Serbia; Belgrade Serbia
5. Izmir Cancer Registry, Izmir Hub; Izmir and Hacettepe University Institute of Public Health; Ankara Turkey
6. Greater Poland Cancer Registry, Department of Cancer Prevention and Epidemiology; Greater Poland Cancer Center; Poznan Poland
7. Croatian National Cancer Registry; Croatian Institute of Public Health; Zagreb Croatia
8. Cancer Registry of the Republic of Slovenia; Institute of Oncology; Ljubljana Slovenia
9. North Region Cancer Registry of Portugal; Portuguese Oncology Institute of Porto; Porto Portugal
10. Belarusian Research Center for Pediatric Oncology, Hematology, and Immunology; Childhood Cancer Subregistry of Belarus; Minsk Belarus
11. Central Region Cancer Registry of Portugal; Portuguese Oncology Institute of Coimbra; Coimbra Portugal
12. Regional Cancer Registry of Iasi; National Institute of Public Health; Iasi Romania
13. Regional Cancer Registry of Cluj; Ion Chiricuta Oncological Institute; Cluj-Napoca Romania
14. Cyprus Cancer Registry, Health Monitoring Unit; Ministry of Health; Nicosia Cyprus
15. Malta National Cancer Registry, Department of Health Information and Research; Valletta Malta
16. Cancer Registry, Department for Epidemiology of Noncommunicable Diseases, Center for Disease Prevention and Control; Institute of Public Health; Podgorica Montenegro
17. Department of Neurosurgery; Aghia Sophia Children's Hospital; Athens Greece
18. Second Department of Radiology, Radiotherapy Unit, Attikon University Hospital, School of Medicine; National and Kapodistrian University of Athens; Greece Athens
19. Neurosurgery Department; Errikos Dunant Hospital Center; Athens Greece
20. Neurosurgical Institute; Ioannina University School of Medicine; Ioannina Greece
21. Neurosurgical Department; General Nikaia Piraeus Hospital; Athens Greece
22. Department of Neurosurgery and Gamma Knife Radiosurgery; Hygeia Hospital; Athens Greece
23. Department of Pediatric Hematology and Oncology; Panagiotis and Aglaia Kyriakou Children's Hospital; Athens Greece
24. Clinical Epidemiology Unit, Department of Medicine; Karolinska Institute; Stockholm Sweden