2019 Volume 68 Issue 9 Pages 605-612
In case of a measurement of reference air kerma rate for 192Ir HDR brachytherapy, source geometry factor ksg is required to correct the response of a well-type chamber. In this work we determined ksg by actual measurement using three sources (mHDR-V2, VS2000, Ir2.A85-2), which are used at Japanese hospitals. The correction factors to convert the calibration coefficient for mHDR-V2 to that of others were calculated to be 0.987 and 1.002, respectively. Since well-type chambers are calibrated using mHDR-V2 source in Japan, these correction factors enable Japanese users to measure reference air kerma rate of another source types.