Abstract
Optically simulated luminescent dosimeters (OSLDs) have been commonly used in research or clinical dose measurements due to their high sensitivity and can be read out multiple times. However, they have energy dependence, and they exhibit an over-response to low energy photons to misestimate the dose. This study used OSLDs and thermoluminescent dosimeters (TLDs) irradiating with three photon energy (100 kV, 120 kV,6 MV) to measure the doses at in-field and out-of-field locations in different depth. Moreover, we calculated the dose response ratio (ROSLD1/ROSLD2) from measurement and used Monte Carlo methods to simulate the ratio of with and without filters in different energies. Effective energy and the correction factor would be decided to reduce the error. The results show that OSLD have less energy dependence in the 6 MV high-energy photon irradiation. The dose errors after the verification compared to TLD are ranged from -20.26 %~27.46 %. In the low-energy photon irradiation (100 kV and 120 kV), OSLD showed energy dependence seriously and the dose errors compared to TLD are range from 66.67 % to 175 % before modification and 15.58 % to 25.47 % after modification. In this study we established a method to reduce the dose errors of OSLD caused by the energy dependence, by means of the modification, errors due to energy dependence can be reduced effectively.