A standard graphite calorimeter for dosimetry in brachytherapy with high dose rate¹⁹²Ir sources

Abstract

Within the framework of the JRP06 European project 'Increasing Cancer Treatment Efficacy Using 3D Brachytherapy', a prototype of a graphite standard calorimeter for the measurement of the absorbed dose rate to water, , for 192Ir sources used in high dose rate (HDR) brachytherapy has been developed at the Italian National Institute of Ionizing Radiation Metrology (ENEA-INMRI). The calorimeter was tested at the Sant'Andrea Hospital in Rome, where measurements were performed in the quasi-adiabatic mode of operation using an 192Ir MicroSelectron® HDR V2 source. The measurements showed a reproducibility of about 1%, while the combined standard uncertainty on the value at the distance of 1 cm from the source was estimated as 1.4%, lower than the uncertainty of determined from the reference air-kerma rate.