中国医学装备2017，Vol.14Issue(4)：65-68,4.DOI:10.3969/J.ISSN.1672-8270.2017.04.017
不同系统摆位误差对鼻咽癌双弧VMAT及动态IMRT计划中剂量分布影响的比较
Comparison on different system setup error on the effect of dose distribution for nasopharyngeal carcinoma therapy:double arc VMAT and dynamic IMRT
戴鹏 1张平 1赖名耀 1罗龙辉 1吴伟 1蔡林波1
作者信息
- 1. 广东三九脑科医院肿瘤综合治疗中心 广东 广州 510510
- 折叠
摘要
Abstract
Objective: To compare the dose distribution effect of the setup error on the double arc volumetric modulated arc therapy (VMAT) and dynamic intensity modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods: Six NPC cases were planned with the same dose prescription and objective constrains by means of 2-arc VMAT and dynamic IMRT respectively. To simulate the setup errors in two systems, respectively, which horizontally remove 3mm and 5mm at three directions (left-right, anterior-posterior, cranial-caudal). To compare the original plan and the simulated plan, and observe the influence of dose distribution of two radiotherapy technology for target and organs at risk (OAR) under different errors. Results:The influences both of 3mm and 5mm setup errors for the dose distribution (GTV D98) were similar between IMRT and VMAT(t=-0.402, t=-0.125; P>0.05); under 5mm setup errors, the dose distribution (CTV D95) of double arc VMAT was statistical significant higher than dynamic IMRT (t=3.572, P<0.05 ), and especially in anterior-posterior and cranial-caudal, the most change was simulated plan was lower 5% than original plan. On organs at risk, under the same errors, the risk of dynamic IMRT was higher than that of double arc VMAT for brainstem and crystalline lens Dmax; the differences between dynamic IMRT and double arc VMAT were not statistical significant on the changes of spinal cord (Dmax) and parotid gland (D50); under one error, the dose change of OARs was more obvious than target area; even the largest increasing range nearly 50%. Conclusion:The sensitivity of setup error of double arc VMAT is higher than dynamic IMRT, and its protective capability for brainstem and crystalline lens are better than dynamic IMRT. The overexposure of OARs based on setup error is more obvious than target area. If the setup error exceeds 2mm, the setup error should be corrected to ensure the accuracy of radiotherapy in NPC and reduce the mistake radiation of organ at risk.关键词
鼻咽癌/摆位误差/剂量分布/调强放射治疗/容积调强弧形治疗Key words
Nasopharyngeal carcinoma/Setup error/Dose distribution/Intensity modulated radiotherapy/Volumetric modulated arc radiotherapy分类
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戴鹏,张平,赖名耀,罗龙辉,吴伟,蔡林波..不同系统摆位误差对鼻咽癌双弧VMAT及动态IMRT计划中剂量分布影响的比较[J].中国医学装备,2017,14(4):65-68,4.
