1. Fonaments Clinics Dpt., Faculty of Medicine, Universitat de Barcelona, 08036 Barcelona, Spain
2. Radiation Oncology Dpt., Hospital Clinic-Universitat de Barcelona, 08036 Barcelona, Spain
3. Cancer Center, Henan Provincial People’s Hospital, Zhengzhou 450003, China
4. Danish Center for Particle Therapy, Institute of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark
5. Radiation Oncology Dpt., Institut Gustave Roussy, 94805 Villejuif, France
6. Radiation Oncology Dpt., Radiotherapie Groep, 6815 AD Arnhem, The Netherlands
7. Maria Sklodowska-Curie National Research Institute of Oncology, 44-102 Gliwice, Poland
8. Institut Català d’Oncologia, l’Hospitalet de Llobregat, 08908 Barcelona, Spain
9. Mount Vernon Cancer Centre, Northwood, Middlesex HA6 2RN, UK
10. Radiation Oncology Dpt., Princess Margaret Hospital, University Health Network, Toronto, ON M5G 2M9, Canada
11. Radiation Oncology Department, Institute of Oncology Ljubljana, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
12. Department of Radiation Oncology, Medical University of Vienna, 1090 Vienna, Austria
13. Radiation Oncology Dpt., University Hospital Gasthuisberg, 3000 Leuven, Belgium