Robust Radiobiological Optimization for Proton Therapy Treatment Planning

摘要

In therapeutic proton beam therapy the choice of RBE values for different tissues remains a contentious issue. We propose a worst case optimization method based on the phe-nomenological model for the RBE presented by Wilkens and Oelfke (2004). The intention of this approach is to achieve robustness in the plan towards uncertainties in the parameters of the biological effect model. Considering these uncertainties we construct a biological worst case scenario in which the lowest effect in the target is assumed to occur simultaneously with the highest effect in the non-target tissues. Optimizing a weighted combination of the nominal and worst case effect allows one to account for the uncertainties in the biological data and helps to attenuate the impact of the differences in the biological setup. The proposed optimization minimizes variations in the target volume effective dose in the presence of an uncertain RBE value.