TLD-based quality audit for radiotherapy dosimetry under reference and non-reference condition in Henan province / 中华放射医学与防护杂志

ABSTRACT

Objective To verify the reliability of radiotherapy dosimetric parameters in reference and non-reference conditions using thermoluminescent dosimeters (TLDs).Methods Using the established TLD method,the dose variations with different radiation field sizes and 45 ° wedge plate were verified for 10 photon beams of 6 MV,together with dosimetric parameters at the point of maximum axial dose for 4 electron beams of 9 MeV under reference and non-reference conditions.Comparisons were made between TLD results and finger ionization chamber results.Results The average relative deviation,for 6 MV photon beams,between TLD results and finger ionization chamber measurements was 4.7％,within ± 7％ as required by the IAEA.The average relative deviation,for 9 MeV electron beam,between TLD results and plane parallel ionization chamber measurements was 2.4 ％,not beyond ± 5％ permitted by IAEA.Conclusions Using TLD method to verify the radiotherapy dosimetric parameters in reference and non-reference conditions was reliable,simple and feasible.