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Uncertainties in high precision radiation therapy: Impact of deformable image registration methods and of delineation variations on the accumulating dose distribution

高精度放射治疗的不确定性：可变形图像配准方法和轮廓变化对累积剂量分布的影响

基本信息

批准号：
252959556
负责人：
Dr. Kristina Giske
金额：
--
依托单位：
Klinik für RadioOnkologie und Strahlentherapie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/252959556?language=en
关键词：
Uncertainties precision radiation therapy Impact

项目摘要

In recent years, technical developments in radiation therapy have resulted in ever more precise dose application techniques; hence, modern techniques are also referred to as high-precision radiotherapy. The physical dose can be applied precisely to the tumor in the defined target volumes while sparing the adjacent organs at risk from irradiation.Many developments were necessary to achieve this improved precision. Improved dose calculation and optimization methods allowed for the computer-assisted planning of complex irradiation plans that can also cover convex and irregular shaped target volumes. The fusion of imaging devices with irradiation devices allowed for a reduction in positioning uncertainties and made it possible to visualize anatomical changes during radiation therapy. Today, image processing methods help to relocate target volumes and organs at risk at every point during the treatment course; this allows adapting the irradiation plan precisely to temporal changes. However, using these methods, the radiation therapy chain has also become more complex. Even though the respective steps in the treatment course carry only small uncertainties, the uncertainties add up during the iterative use of the methods in the therapy course.To assess the quality of the entire treatment course, or to be able to intervene in the treatment course e.g. by employing various correction strategies, it is required to take the accumulated uncertainties into consideration. Therefore, it is important to simulate the entire treatment course and to include the occurring uncertainties.It is still a challenge to perform such a simulation. Especially the determination of temporal variable deformations through deformable image registration methods is hard to validate. Different methods result in different results for the same input images; in addition, the quality of the methods depends on the context in which they are used. These uncertainties will have to be reflected in the uncertainties of the accumulated dose distribution.The goal of this research project is to integrate common image registration methods with a treatment planning system. We plan to investigate image registration methods regarding their uncertainties in dose distribution by developing a new virtual patient and employing widely used evaluation methods. This will enable us to determine the image registration methods most suited for usage in radiation therapy and to evaluate the propagation of uncertainties in the accumulated dose distribution. With this we can e.g. compare competing adaptive correction strategies, or determine the potentially remaining dose tolerance in case of planning a re-irradiation of previously treated patients.

近年来，放射治疗的技术发展导致了更精确的剂量应用技术;因此，现代技术也被称为高精度放射治疗。物理剂量可以精确地施加到肿瘤的定义的目标体积，同时保护邻近器官的辐射风险。许多发展是必要的，以实现这一改进的精度。改进的剂量计算和优化方法允许计算机辅助规划复杂的照射计划，也可以覆盖凸形和不规则形状的靶体积。成像设备与辐照设备的融合可以减少定位的不确定性，并使放射治疗期间的解剖学变化可视化成为可能。如今，图像处理方法有助于在治疗过程中的每个点重新定位靶体积和有风险的器官;这允许精确地调整照射计划以适应时间变化。然而，使用这些方法，放射治疗链也变得更加复杂。即使治疗过程中的各个步骤只带有很小的不确定性，但是在治疗过程中反复使用这些方法的过程中，不确定性会累积起来。为了评估整个治疗过程的质量，或者能够通过采用各种校正策略来干预治疗过程，需要考虑累积的不确定性。因此，对整个治疗过程进行仿真并考虑到可能出现的不确定性是非常重要的，而进行这样的仿真仍然是一个挑战。特别是通过可变形图像配准方法确定时间可变变形很难验证。对于相同的输入图像，不同的方法会产生不同的结果;此外，方法的质量取决于使用它们的上下文。这些不确定性将不得不反映在累积剂量distribution.The目标的不确定性的研究项目是将共同的图像配准方法与治疗计划系统。我们计划通过开发一个新的虚拟患者和采用广泛使用的评估方法，研究图像配准方法的剂量分布的不确定性。这将使我们能够确定最适合用于放射治疗的图像配准方法，并评估累积剂量分布中不确定性的传播。这样，我们可以比较竞争性自适应校正策略，或者在计划对先前治疗的患者进行再照射的情况下确定潜在的剩余剂量耐受性。