Takegawa Hideki
Igaku Butsuri. 2013;33(3):120-6.
Four-dimensional radiation therapy (4DRT) and adaptive radiation therapy (ART) are treatments to account for respiratory motion and anatomical changes during a course of treatment, respectively. Recent development of both imaging and delivery techniques made these radiation therapy possible. In these planning, dose distributions are calculated with multiple image sets for example each respiratory phase constituting 4-dimensional computed tomography and cone-beam computed tomography acquired on each treatment day. To evaluate overall dose distributions, we need to accumulate dose distributions calculated with multiple image sets. However, pixel-wise dose accumulation is impossible because it does not accumulate dose based on anatomy if image sets are different. Deformable image registration (DIR) is used to find corresponding anatomical points between image sets. Thus, dose accumulation based on DIR is a promising technology to enable us to evaluate overall dose distributions of 4DRT and ART. In this article, I will briefly introduce dose accumulation based on DIR and its application to 4DRT and ART.
四维放射治疗（4DRT）和自适应放射治疗（ART）分别是用于在一个疗程中考虑呼吸运动和解剖结构变化的治疗方法。成像技术和放疗技术的最新发展使这些放射治疗成为可能。在这些治疗计划中，例如使用构成四维计算机断层扫描的每个呼吸阶段以及在每个治疗日获取的锥形束计算机断层扫描等多个图像集来计算剂量分布。为了评估总体剂量分布，我们需要累积用多个图像集计算出的剂量分布。然而，逐像素剂量累积是不可能的，因为如果图像集不同，它不会基于解剖结构累积剂量。可变形图像配准（DIR）用于找到图像集之间相应的解剖学点。因此，基于DIR的剂量累积是一项很有前景的技术，使我们能够评估4DRT和ART的总体剂量分布。在本文中，我将简要介绍基于DIR的剂量累积及其在4DRT和ART中的应用。
