[1] Paul Scherrer Inst, Ctr Proton Therapy, Villigen, Switzerland
[2] Inselspital Bern, Bern, Switzerland
[3] Univ Bern, Univ Hosp Bern, Dept Radiat Oncol, Inselspital, Bern, Switzerland
[4] PSI, Villigen, Switzerland
[5] PSI, CH-5210 Villigen, Switzerland
[6] Zentrum Kinderheilkunde Univ Klinikum Bonn, Bonn, Germany
[7] Paul Scherrer Inst, Villigen, Switzerland
[8] Bern Univ Hosp, Dept Radiat Oncol, Inselspital, Bern, Switzerland
[9] Univ Bern, Bern, Switzerland