Dose-homogeneity Driven Beam Delivery System Performance Requirements for MedAustron

MedAustron [1], the Austrian hadron therapy center is currently under construction. Irradiation will be performed using active scanning with proton and carbon ion pencil beams. Major beam delivery system contributors to dose heterogeneities are evaluated: beam position, beam size and spot weight errors. Their individual and combined effect on the dose distribution is quantified, using semianalytical models of lateral beam spread in the nozzle and target and depth-dose curves for protons and carbon ions. Deduced requirements on critical parts of the beam delivery system are presented. Preventive and active methods to suppress the impact of beam delivery inaccuracies are proposed.