Energy loss measurements of 27 MeV protons irradiating water-equivalent materials

The use of proton beams represents one of the most innovative fields of application in radiotherapy. The interest is growing up in considering the possibility offered by proton beams and, in general, by ions to increase the target dose while reducing the outside dose at healthy tissues. Clinical proton beam dosimetry represents a fundamental aspect to exploit the features of this therapy. In this paper we will report depth-dose measurements in equivalent tissue materials (polyethylene and polytetrafluoroethylene). A 27 MeV proton beam delivered by the LNS tandem accelerator, a Markus ionization chamber and LiF-PTFE thermoluminescent disks were used to perform these investigations. Calculations of the delivered doses and the experimental set-up will be described in detail. (orig.)