Proton Beam Dosimetry Intercomparison

The Third Korea-Japan Joint Meeting on Medical Physics and The Second Asia Oceania Congress of Medical Physic

Proton Beam Dosimetry -Protocol and intercomparison in Japan

International Symposium on Standards and Codes of Practice in Medical Radiation Dosimetr

Proton beam dosimetry:Protocol and intercomparison in Japan

A new protocol for dosimetry in external beam radiotherapy was published by theJapan Society of Medical Physics in September 2002.The protocol deals with proton andheavy ion beams and with electron and photon beams, using the absorbed dose to waterformalism with calculated ND,w factors. An intercomparison programme was carried outwith the new protocol to establish interinstitutional uniformity in proton beamdosimetry. The absorbed doses were measured with different cylindrical ionizationchambers in a water phantom at a position of 30 mm residual range for a proton beamthat had a range of 155 mm and a spread out Bragg peak 60 mm wide. As a result, theintercomparison showed that the use of the new protocol would improve the +/-1.0%(one standard deviation) and 2.7% (maximum discrepancy) differences in absorbeddoses stated by the participating institutions to +/-0.3% and 0.9%, respectively. The new protocol will be adopted by all the participants

Proton Beam Dosimetry Intercomparison

The Third Korea-Japan Joint Meeting on Medical Physics and The Second Asia Oceania Congress of Medical Physic