Fluence correction for plastic phantoms

Reference dosimetry in clinical practice for particle therapy is usually performed in water phantoms. However, there a certain situations where the use of plastic phantoms is more convenient, e.g. quality assurance for a gantry. Due to differences in the non-elastic nuclear cross sections between plastic materials and water and therefore differences in the attenuation of the primary beam, fluence correction factors are considered as an option to correct arising dose differences. The presentation includes an overview of the physical principles of beam attenuation and the impact on quality assurance in clinical particle therapy. It will give detailed information on measurement setups and will discuss recently taken data, as well as planned experiments for the near future.