1. Danish Centre for Particle Therapy, Aarhus, Denmark;
2. Department of Radiation Oncology, University of Florida, Jacksonville, FL, USA;
3. Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway;
4. Department of Radiotherapy, Instituto Português de Oncologia de Lisboa Francisco Gentil, EPE, Lisbon, Portugal;
5. Department of Neuroradiology/Biomedicine, Aarhus University Hospital, Aarhus, Denmark;
6. Department of pediatrics, Aarhus University Hospital, Aarhus, Denmark