【摘要】 目的核查放射治疗计划系统(TPS)计算病人治疗剂量的非均匀野剂量校正。方法将插有TLD的聚苯乙烯固体模体,聚苯乙烯/肺固体模体,聚苯乙烯/骨固体模体分别经CT扫描,影像分别传入TPS并计算高能X射线下监督单位数,使传递给中心束轴TLD剂量为2 Gy。在高能X射线下完成TLD照射,照射后的TLD经测量、剂量计算,D(TLD)与D(TPS)剂量比值在0.95~1.05范围为可接受范围。结果核查结果表明,光子线束均匀模体轴上(P)剂量和非均匀骨模体轴上(BP)剂量核查结果较好。非均匀肺模体轴上(LP)和离轴(LL)剂量核查结果误差很大。结论光子线束非均匀性剂量校正在放射治疗中是非常重要,尤其是肺组织。校正不当,对于肺组织剂量误差也可达到11.1%,离轴情况下更多达18.4%。对于骨组织剂量误差较小。更多还原

【Abstract】 Objective To check the heterogeneity corrected dose calculations performed by the treatment planning system.Methods Homogeneous polystyrene solid phantom with TLD,Polystyrene / lung solid phantom with TLD and Polystyrene / bone solid phantom with TLD will be required to be CT scanned respectively,images exported to the TPS and monitor units calculated as if to deliver 2Gy to the TLD on photon beam axis. The TLDs was irradiated by high energy X- ray. TLDs irradiated by measuring and dose calculation,and D( TLD) / D( TPS) dose ratio in 0. 95 to 1. 05 was acceptable. Results Verification results showed that homogeneous polystyrene solid phantom on axis( P) dose and polystyrene / bone solid phantom on axis( BP)dose are good,polystyrene / lung solid phantom on axis( LP) and off- axis( LL) relative deviation are large. Conclusion Heterogeneity of photon beam dose correction is very important in radiotherapy,especially in the lung tissue. Improper correction,the deviation for lung tissue can also be reached 11. 1%,off- axis cases up to 18. 4%. The deviation for bone tissue is smaller.更多还原