Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
J Radiat Res. 2013 May;54(3):569-77. doi: 10.1093/jrr/rrs123. Epub 2012 Dec 18.
The purpose of this study was to develop a computer-aided method for determination of beam arrangements based on similar cases in a radiotherapy treatment-planning database for stereotactic lung radiation therapy. Similar-case-based beam arrangements were automatically determined based on the following two steps. First, the five most similar cases were searched, based on geometrical features related to the location, size and shape of the planning target volume, lung and spinal cord. Second, five beam arrangements of an objective case were automatically determined by registering five similar cases with the objective case, with respect to lung regions, by means of a linear registration technique. For evaluation of the beam arrangements five treatment plans were manually created by applying the beam arrangements determined in the second step to the objective case. The most usable beam arrangement was selected by sorting the five treatment plans based on eight plan evaluation indices, including the D95, mean lung dose and spinal cord maximum dose. We applied the proposed method to 10 test cases, by using an RTP database of 81 cases with lung cancer, and compared the eight plan evaluation indices between the original treatment plan and the corresponding most usable similar-case-based treatment plan. As a result, the proposed method may provide usable beam arrangements, which have no statistically significant differences from the original beam arrangements (P > 0.05) in terms of the eight plan evaluation indices. Therefore, the proposed method could be employed as an educational tool for less experienced treatment planners.
本研究的目的是开发一种基于放射治疗计划数据库中立体定向肺放射治疗相似病例的计算机辅助方法来确定射束排列。基于以下两个步骤自动确定基于相似病例的射束排列。首先，基于与计划靶区、肺和脊髓的位置、大小和形状相关的几何特征，搜索五个最相似的病例。其次，通过线性注册技术，将目标病例与五个相似病例的肺区域进行配准，自动确定五个目标病例的射束排列。为了评估射束排列，通过将第二步确定的射束排列应用于目标病例，手动创建了五个治疗计划。根据包括 D95、平均肺剂量和脊髓最大剂量在内的八个计划评估指标，对五个治疗计划进行排序，选择最可用的射束排列。我们将该方法应用于 10 个测试病例，使用了一个包含 81 例肺癌病例的 RTP 数据库，并比较了原始治疗计划和相应的最可用相似病例基础治疗计划之间的八个计划评估指标。结果表明，在八个计划评估指标方面，所提出的方法可以为经验较少的治疗计划者提供没有统计学差异的可用射束排列（P＞0.05）。因此，该方法可以作为一种教育工具，用于经验不足的治疗计划者。
