Compared to conventional high-energy photon beams, proton therapy has the potential to achieve an improved tumor control by sparing surrounding normal tissue. However, the accurate delivery of absorbed dose distributions is essential to assess the effectiveness of radiotherapy in terms of tumor control and normal tissue complication probabilities. Several factors contribute to the overall accuracy of a treatment. One of them is related to the algorithms used for the determination of ionization chamber quality factors and for the computation of absorbed dose distributions in patients. In this context, the Monte Carlo method is considered the state-of-the-art for solving radiation transport problems.

In this seminar an overview of the current situation related to the determination of ionization chamber quality factors in proton therapy will be given. Current efforts being developed at the WPE in this field will be presented, in particular the benchmarking process of the newly developed extension for proton simulation within the Monte Carlo general-purpose radiation transport code PENELOPE.