Ren Qiang, Li Gui, Wang Yu, Wu Yican
Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, China.
Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China.
Med Phys. 2012 Jun;39(6Part12):3750. doi: 10.1118/1.4735264.
With the advancement in dosimetric devices and the development of dose reconstruction algorithm, the implementation of dose-guided radiation therapy (DGRT) is feasible. In order for DGRT to be performed clinically, a prototype of DGRT was developed in this study.
The prototype adopted a strategy for DGRT that adjusted the treatment plan for future fractions to compensate for dosimetric errors from past fractions, which included four main functional modules: management of patient plan information, dose reconstruction, dose evaluation, plan adjustment. we developed our dose reconstruction procedure, including the dosimetric calibration of the portal image acquired using electronic portal image device (EPID) during treatment and three-dimensional (3D) patient dose reconstruction based on Monte Carlo Finite-size pencil beam (MCFSPB) model and Conjugate-gradient (CG) algorithm developed by FDS Team (www.fds.org.cn). The dose evaluation tools including 3D Gamma analysis and dose-volume-histogram (DVH) analysis were also available which were used to compare the reconstruction dose with the planning dose. Finally we re-optimizing the treatment plan according to the information provided by dose evaluation.
In order to validate the availability of the workstation prototype, lots of experiments were carried out based on head phantom. The result showed that disagreement between the reconstructed dose and the planning dose (calculated by the Accurate Radiotherapy System (ARTS) developed by FDS Team) was observed by the DGRT prototype when there existed position error for head phantom or the accelerator delivery was not accurate.
An effective prototype for DGRT has been developed. With these techniques, the clinical implementation of DGRT is possible in the near future. Supported by the National Natural Science Foundation under grant No.30900386 and the National Science Foundation of Anhui Province (Nos.090413095 and 111040606Q55).
随着剂量测定设备的进步和剂量重建算法的发展，实施剂量引导放射治疗（DGRT）是可行的。为了使DGRT能够在临床上得以应用，本研究开发了一种DGRT原型。
该原型采用了一种DGRT策略，即调整未来分次的治疗计划以补偿过去分次中的剂量测定误差，它包括四个主要功能模块：患者计划信息管理、剂量重建、剂量评估、计划调整。我们开发了剂量重建程序，包括对治疗期间使用电子射野影像装置（EPID）获取的射野图像进行剂量测定校准，以及基于蒙特卡罗有限尺寸笔形束（MCFSPB）模型和由FDS团队（www.fds.org.cn）开发的共轭梯度（CG）算法进行三维（3D）患者剂量重建。剂量评估工具包括3D伽马分析和剂量体积直方图（DVH）分析，也可用于比较重建剂量与计划剂量。最后，我们根据剂量评估提供的信息对治疗计划进行重新优化。
为了验证工作站原型的可用性，基于头部模体进行了大量实验。结果表明，当头部模体存在位置误差或加速器输送不准确时，DGRT原型观察到重建剂量与计划剂量（由FDS团队开发的精确放射治疗系统（ARTS）计算）之间存在差异。
已开发出一种有效的DGRT原型。通过这些技术，DGRT在不久的将来有可能实现临床应用。得到国家自然科学基金项目（批准号：30900386）和安徽省自然科学基金（批准号：090413095和111,040,606Q55）的资助。
