河南省核查放射治疗参考与非参考条件下剂量学参数方法验证

目的 研究用热释光剂量计（TLD）方法核查放射治疗参考条件和非参考条件下剂量学参数的可靠性验证。方法 在参考条件和非参考条件下，用建立的TLD方法，核查10条6 MV光子线束剂量随照射野大小和45°楔形板等变化，4条9 MeV电子线束轴向最大剂量点处等剂量学参数，TLD估算结果与剂量仪测量结果进行对比。结果 6 MV光子线束TLD估算结果与指形电离室测量结果的平均相对偏差为4.7%，按照IAEA要求允许偏差不超过±7%；9 MeV电子线束TLD估算结果与平行板电离室测量结果平均相对偏差为2.4%，均未超过IAEA允许偏差要求（±5%）。结论 用TLD核查参考条件和非参考条件下放射治疗剂量学参数方法可靠，简单易行。

TLD-based quality audit for radiotherapy dosimetry under reference and non-reference condition in Henan province

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.