摘要目的 研究调强放疗(IMRT)多叶光栅野吸收剂量和二维剂量分布验证方法.方法 选取8台医用加速器,6MVX射线照射野为5 cm×5 cm时,分别使用热释光剂量计(TLD)和EBT3胶片剂量计核查调强放疗多叶光栅野光子线束吸收剂量,并使用EPT3胶片剂量计核查调强放疗多叶光栅野光子线束二维剂量分布.结果 使用多叶光栅野热释光验证方法和胶片剂量计方法,剂量相对偏差范围分别是-1.4％ ～6.8％和-1.8％ ～7.8％.有7台结果符合国际原子能机构(IAEA)剂量偏差在±5％的要求;二维剂量分布通过率范围为73.4％ ～97.0％,有7台符合二维剂量分布通过率＞90％的要求.结论 热释光剂量计和胶片剂量计用于调强放疗多叶光栅野剂量学参数验证是可行的,适合审管部门大规模开展的IMRT的治疗计划系统(TPS)吸收剂量和二维剂量分布验证.

abstractsObjective To explore the dosimetric verification method for absorbed dose and twodimensional dose distribution generated through multi-leaf collimator in radiotherapy.Methods A total of 8 medical accelerators were selected in Jiangsu province.Under 6 MV X-rays with a 5 cm × 5 cm field,the thermoluminescent dosimeter (TLD) and EBT3 radiochromic film (RCF) were used to audit the values calculated by treatment planning system (TPS).RCF was used to verify two-dimensional dose distribution under the 6 MV MLC beams for intensity modulated radiation therapy (IMRT).Results The relative dose deviation was from-1.4％ to 6.8％ for TLD and from-1.8％ to 7.8％ for RCF,with 7 accelerators meeting with the IAEA deviation requirement of ± 5％.The passing rates of two-dimensional dose distribution were between 73.7％ and 97.0％,with 7 accelerators greater than 90％.Conclusions TLD and RCF are feasible and suitable for large-scale verification of IMRT TPS absorbed dose and twodimensional dose distribution.