【摘要】 目的：探讨放疗科3台加速器束流匹配后互换执行容积旋转调强放射治疗（VMAT）计划的准确性。方法：随机选取18例头颈部、胸腹部和盆腔部患者，采用Synergy1、Synergy2和Versa HD 3台加速器模型分别制作VMAT放疗计划Plan_Synergy1,Plan_Synergy1和Plan_VersaHD。同一VMAT计划（6 MV X射线）分别在3台加速器执行，采用电离室和Delta4分别测量绝对点剂量误差和相对三维剂量γ通过率（3 mm/3%）。互换执行VMAT计划后，点剂量和相对剂量的测量结果与治疗计划系统（TPS）计算的结果比较，评估3台加速器束流匹配后VMAT计划互换执行的可行性。结果：Plan_Synergy1计划分别在Synergy1、Synergy2、VersaHD执行时，测得的点剂量与TPS计算的偏差分别为-0.27%±0.87%、-0.88%±1.74%和0.37%±2.18%，测量的相对剂量与TPS计算相比，γ通过率分别为99.84%±0.31%、98.89%±1.32%和99.16%±1.12%;Plan_Synergy2计划分别在Synergy1、Synergy2、VersaHD执行时测得的点剂量与TPS计算的偏差分别为0.24%±1.98%、0.15%±1.97%和-0.09%±0.66%，测量的相对剂量与TPS计算相比，γ通过率分别为98.75%±1.38%、99.77%±0.42%和99.41%±1.66%;Plan_VersaHD计划分别在Synergy1、Synergy2、Versa HD执行时测得的点剂量与TPS计算的偏差分别为-0.57%±1.07%、-0.42%±2.10%和-1.55%±1.62%，测量的相对剂量与TPS计算相比，γ通过率分别为97.79%±1.61%、98.75%±1.37%和99.78%±0.60%。在3台加速器互换执行VMAT计划中，点剂量偏差均在3%以内，相对剂量偏差的γ通过率均在95%以上，均满足临床要求。结论：3台医科达加速器束流（6 MV X射线）匹配后可互换执行VMAT计划。更多还原

【Abstract】 Objective To investigate the possibility of swapping volumetric modulated arc therapy （VMAT） plan across 3beam-matched linear accelerators.Methods Synergy1,Synergy2 and VersaHD were used to generate VMAT plans named Plan_Synergy1,Plan_Synergy1and Plan_VersaHDfor 18 cases with the tumor located in head and neck,chest and abdomen,or pelvis.The same VMAT plan （6 MV X-ray） was executed sequentially on 3 accelerators.The absolute point dose error and relative threedimensional dose distribution with gamma passing rate （3 mm/3%） measured by ion chamber and Delta4 were compared with the results calculated by treatment planning system for assessing the feasibility of swapping VMAT radiotherapy plan across 3 beam-matched linear accelerators.Results The deviations between measured point dose of Plan_Synergy1executed on 3accelerators （Synergy1,Synergy2 and VersaHD） and TPS calculation were （-0.27±0.87）%,（-0.88±1.74）%and （0.37±2.18）%,respectively;and the comparison between measured relative dose and TPS calculation showed that the gamma passing rates were （99.84±0.31）%,（98.89±1.32）%and （99.16±1.12）%,respectively.For Plan_Synergy2,the deviations between measured point dose and TPS calculation were （0.24±1.98）%,（0.15±1.97）%and （-0.09±0.66）%,respectively;and the gamma passing rates of relative dose were （98.75±1.38）%,（99.77±0.42）%and （99.41±1.66）%,respectively.For Plan_VersaHD,the deviations between measured point dose and TPS calculation were （-0.57±1.07）%,（-0.42±2.10）%and （-1.55±1.62）%,respectively;the gamma passing rates of relative dose were （97.79±1.61）%,（98.75±1.37）%and （99.78±0.60）%,respectively.When VMAT plan was swapped across 3 Elekta beam-matched linear accelerators,the point dose deviations were within the range of±3%,and the gamma passing rate of relative doses were higher than 95%,meeting clinical requirements.Conclusion VMAT plan can be swapped across 3 Elekta linear accelerators after beam match （6 MV X-ray）.更多还原