Measurement of radiation dose distribution in minipig physical phantom using RPLGD

Abstract

Radio-photoluminescence glass dosimeter (RPLGD) has many advantages such as small size, high sensitivity, low fading effect, excellent dose linearity and repeatability. Because of these advantages, RPLGDs were used to measure the absorbed dose as in-vivo dosimeter. In Korea Institute of Radiological and Medical Sciences (KIRAMS), a minipig physical phantom was applied to evaluate the dose distribution for animal irradiation study. In this study, RPLGDs were used as a dosimeter to evaluate the dose distribution in the 5th and 25th slices. For the reliable result, RPLGDs were irradiated to evaluate the expanded measurement uncertainty. The expanded measurement uncertainty of RPLGD was determined as 6.08% with a coverage factor of k=2. Additionally, the framework of the Geant4 toolkit was used to verify the dose distribution by using RPLGD measurement under the same experiment condition. To analyze the linearity between the RPLGD measurements and Geant4 simulation, each of absorbed doses was compared according to the measurement points in the minipig physical phantom. As a result, the coefficients of determination (R2) were evaluated as 0.9767 and 0.9852 at each slice of the 5th and 25th.