A conceptual study on real-time adaptive radiation therapy optimization through ultra-fast beamlet control.
A conceptual study on real-time adaptive radiation therapy optimization through ultra-fast beamlet control.
复制标题
通过超快子束控制进行实时自适应放射治疗优化的概念研究。
DOI：
10.1088/2057-1976/ab3ba9
复制
发表时间：
2019
影响因子：
1.4
通讯作者：
Liu,Xinmin
中科院分区：
文献类型：
--
作者：
Wiersma,RodneyD;Liu,Xinmin
放射治疗（RT）领域中的中心问题是如何以完全考虑解剖位置随时间变化的方式最佳地向患者递送剂量。由于当前RT是一个静态过程，其中在治疗开始之前计算射束强度，解剖学偏差可能导致剂量符合性差。为了克服这些局限性，我们提出了一个完全动态的实时自适应放射治疗（RT-ART）的优化方法，使用超快速子束控制，以动态地适应患者的运动实时的模拟研究。利用快速旋转线性加速器（LINAC）源（60 RPM）和以100 Hz操作的二进制1D多叶准直器（MLC）来模拟虚拟RT-ART机器。如果实时跟踪的目标运动超过预定义的阈值，则使用快速优化方法求解时间相关的目标函数以计算新的细光束强度，然后将其递送给患者。为了评价该方法，分析了患者产生的连续漂移、阶梯状和周期性部分内运动的系统响应。对于每一种运动类型的调查，RT-ART方法进行了比较，对理想的情况下，没有病人的运动（静态情况下），以及没有使用RT-ART的情况下。在所有情况下，等剂量线和剂量体积直方图（DVH）显示，RT-ART计划的质量大致相同的静态情况下，大大优于没有RT-ART的情况下。基于使用几种不同运动类型的测试，RT-ART能够将剂量符合性恢复到与理想RT输送相似的水平，而没有解剖学变化。随着实时患者运动跟踪和快速计算过程的不断进步，在下一代RT机器上实现RT-ART优化过程具有巨大的潜力。
A central problem in the field of radiation therapy (RT) is how to optimally deliver dose to a patient in a way that fully accounts for anatomical position changes over time. As current RT is a static process, where beam intensities are calculated before the start of treatment, anatomical deviations can result in poor dose conformity. To overcome these limitations, we present a simulation study on a fully dynamic real-time adaptive radiation therapy (RT-ART) optimization approach that uses ultra-fast beamlet control to dynamically adapt to patient motion in real-time. A virtual RT-ART machine was simulated with a rapidly rotating linear accelerator (LINAC) source (60 RPM) and a binary 1D multi-leaf collimator (MLC) operating at 100 Hz. If the real-time tracked target motion exceeded a predefined threshold, a time dependent objective function was solved using fast optimization methods to calculate new beamlet intensities that were then delivered to the patient. To evaluate the approach, system response was analyzed for patient derived continuous drift, step-like, and periodic intra-fractional motion. For each motion type investigated, the RT-ART method was compared against the ideal case with no patient motion (static case) as well as to the case without the use RT-ART. In all cases, isodose lines and dose-volume-histograms (DVH) showed that RT-ART plan quality was approximately the same as the static case, and considerably better than the no RT-ART case. Based on tests using several different motion types, RT-ART was able to recover dose conformity to the level that it was similar to an ideal RT delivery with no anatomical changes. With continued advances in real-time patient motion tracking and fast computational processes, there is significant potential for the RT-ART optimization process to be realized on next generation RT machines.