[1] Odense Univ Hosp, Lab Radiat Phys, Odense, Denmark
[2] Univ Southern Denmark, Inst Clin Res, Odense, Denmark
[3] Univ Sydney, Sch Phys, Inst Med Phys, Sydney, NSW, Australia
[4] Aarhus Univ Hosp, Danish Ctr Particle Therapy, Aarhus, Denmark
[5] Katholieke Univ Leuven, Dept Oncol, Lab Expt Radiotherapy, Leuven, Belgium
[6] UZ Leuven, Radiat Oncol, Leuven, Belgium
[7] Natl Phys Lab, Metrol Med Phys Ctr, Teddington, Middx, England
[8] Erasmus MC, Radiat Oncol, Canc Inst, Rotterdam, Netherlands
[9] Hosp Santa Creu & Sant Pau, Serv Radiofis & Radioproteccio, Barcelona, Spain
[10] Amsterdam Univ Med Ctr, Amsterdam, Netherlands
[11] Univ Hosp Zurich, Radiat Oncol Dept, Zurich, Switzerland