Ion beam transport calculations and treatment plans in particle therapy

In this contribution we report on the various calculational steps which are necessary to obtain reliable treatment plans for carbon ion radiotherapy. We start with the description of radiation action on the microscopic level, using the TRAX simulation code, and proceed to pragmatic pencil beam modelling in order to achieve efficient dose calculations on the three-dimensional grid of computed tomographic images. Biological effects are introduced via the local effect model (LEM), which enables the optimization of complex treatment plans in the context of the treatment planning system TRiP98. Last but not least we discuss the experimental verification of generated treatment plans. We close with a summary on what has been achieved and where future developments are heading.