摘要
目的:研究分别采用Delta4和Arc Check三维探测器阵列对螺旋断层放疗系统(TOMO)的调强计划实施剂量验证的异同。方法:分别采用Scandi Dos公司Delta4三维半导体探测器阵列和Sun Nuclear公司Arc Check三维半导体探测器阵列对10例患者的TOMO调强放疗计划实施验证。通过TOMO系统MVCT成像和配准消除床面沉降的影响,确保实现两种三维探测器阵列的精确摆位。实施治疗质量保证(Delivery Quality Assurance,DQA)计划照射后将探测器阵列测量获得的平面剂量分布与TOMO计划系统模体计划计算获得的平面剂量分布进行比较。采用Gamma分析方法,选择多个不同的剂量标准分析评估验证情况。结果:阈值水平(Threshold,TH)分别为5%、10%、20%、70%、90%时,采用3%/2 mm、3%/3 mm、3%/4 mm、3%/5 mm四种不同剂量偏差/吻合距离剂量标准,γ≤1的平均通过率均超过94.1%,测量所得剂量分布与计算结果在相应平面的几何分布均呈现出良好的一致性。结论:两种三维探测器阵列各具特点,用于TOMO调强放疗计划验证能够获得令人满意的结果 。
Objective To compare the Delta4 three dimensional detector array with the ArcCheck detector array in dose verifica- tion of tomotherapy （TOMO） intensity modulated planning. Methods 10 patients were selected to verify dose distribution in the TOMO plan with the Delta4 and ArcCheck detector arrays. The precise setup of detector arrays was insured by MVCT imaging. The measured dose distribution on the corresponding planes were compared with those calculated by the treatment planning sys- tem （TPS） after the implementation of delivery quality assurance （DQA） plan. Several different dose distribution assessments were chosen to verify the results made by Gamma analysis. Results 4 different doses 3%/2 mm, 3%/3 mm, 3%/4 mm, 3%/5 mm were used when the thresholds were THs, THe0, THe, THTo, THg0. The mean passing rates with γ parameter ≤ 1 were all above 94.1%. The dose distribution measured by these two kinds of three dimensional detector arrays combining corresponding phan toms was well consistent with which was calculated by TPS. Conclusion Three dimensional detector arrays both the Delta4 and ArcCheck with corresponding phantoms can get satisfying results when used in dose verification of TOMO plan.
出处
《中国医学物理学杂志》
CSCD
2015年第2期218-220,238,共4页
Chinese Journal of Medical Physics
基金
全军医学计量专项课题(2011-JL2-005)
