影响容积旋转调强放疗精度的误差因素探测及改进方法研究

项目名称： 影响容积旋转调强放疗精度的误差因素探测及改进方法研究

项目编号： No.81472807

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 李光俊

作者单位： 四川大学

项目金额： 64万元

中文摘要： 容积旋转调强放疗（VMAT）治疗时间短、剂量学特征优秀，因而广泛用于肿瘤放疗。但其计划复杂、对设备要求高，因此VMAT质量保证（QA）方法研究是当前热点。我们研究显示，治疗前个体化QA和治疗时机器参数误差监测是VMAT质量检测的有效手段。前期研究中我们已证实，计划复杂性对VMAT治疗精度影响显著，但其具体影响机制尚不清楚。预实验中我们发现：VMAT治疗时机架旋转、MLC叶片到位、剂量输出精度较好，且与VMAT剂量验证结果的相关性较低。据此，我们推测测定计划参数对VMAT的影响机制，改进加速器物理数据模型和放疗计划设计策略是提高VMAT治疗精度的有效方法。我们拟用统计学方法分析大样本VMAT数据，探测计划和机器参数对VMAT剂量验证的影响及机制，提出VMAT加速器物理模型数据改进方法并建立新的VMAT计划设计策略，提高VMAT治疗精度。本研究将为提高VMAT治疗水平提供了新思路和新方法。

中文关键词： 容积旋转调强放射治疗；质量保证；剂量验证；精度；治疗计划设计

英文摘要： Volumetric-modulated arc therapy (VMAT), which has been widely used in cancer treatment, provides a shorter treatment time, higher efficiency of dose delivery and more conformal dose distribution. For the complexity of VMAT plan and the high precision requirements of TPS and linac, the quality assurance (QA) of VMAT is a hotspot at present. Our study shows that patient-specific QA and monitored treatment parameters are valid methods for VMAT QA. We found that the plan complexity affects the precision of VMAT delivery, but the mechanism is not explicit as yet. We also found that gantry rotational, MLC leaf positioning and MU precision are suitable for VMAT. Accordingly, we infer that the mechanism of VMAT for the planning parameter, the improving method for linac physical model in TPS, and the strategy of treatment planning are effective methods for improving VMAT treatment precision. In this study, in order to enhance the VMAT treatment precision, we will analyse the VMAT planning and delivery data, explore the effect of VMAT for the planning and treatment parameters, explore the mechanism, provide a new method to improve the physical model in TPS, and improve the strategy of treatment planning. This study will provide a new line of thinking and method to improve the level of VMAT treatment.

英文关键词： Volumetric-modulated arc therapy;quality assurance;dose verification;precision;treatment planning