Development and experimental validation of TPS software to determine the out-of-field dose in radiotherapy beams

International audienceEven if the IMRT modality allows a more accurate definition of the target volume in radiotherapy, low doses are still delivered around the tumour to organs at risk. Epidemiological studies demonstrated the relationship between peripheral doses and second cancers or heart diseases. Our aim is to develop a MC tool based on the PENELOPE code to compute the dose at the target volume and the organs at risk in order to enable a decrease of the peripheral dose by adapting the treatment's parameters. This tool will be implemented in a Treatment Planning System (TPS). In this paper we expose the first validation step of the out-of-field MC calculations, using a comparison with measurements in a specific large water tank