剂量调整以补偿在线自适应性放射治疗中累积的分数内运动效应
Erik van der Bijl1, Robert Jan Smeenk1, Lukas Schröder2
1Radiation Oncology, Radboudumc, Geert Grooteplein Zuid 32, Nijmegen, 6500 HB, NETHERLANDS.
Physics in medicine and biology
|May 15, 2025
概括
这项研究使用在线适应性前列腺癌放射治疗中的0毫米规划目标体积 (PTV) 边缘进行了探索. 使用局部补偿的剂量适应方法降低了处于危险的器官剂量,但显示强度下降.
科学领域:
- 辐射瘤学 辐射瘤学
- 医学物理 医学物理
- 癌症治疗方法 癌症治疗方法
背景情况:
- 在线适应性放射治疗 (ART) 旨在通过在治疗期间调整计划来提高治疗准确性.
- 减少计划目标体积 (PTV) 边缘在ART中,特别是在前列腺癌中,这是可取的,但由于运动而具有挑战性.
- 在早期分量中累积的低剂量需要补偿,以确保充分覆盖目标.
研究的目的:
- 评估在前列腺癌在线ART的初始部分中0毫米PTV边缘的可行性.
- 评估剂量适应性策略,包括对最终分量的低剂量进行局部补偿.
- 调查这种方法对注册错误的稳定性.
主要方法:
- 分析了12名前列腺癌患者的运动数据,以模拟治疗场景.
- 创建了0毫米和3毫米PTV边缘的治疗计划,并累积了剂量.
- 一个剂量适应计划补偿了之前分数中遗漏的剂量,对模拟注册错误 (0.5-1.0毫米SD) 进行了稳定性测试.
主要成果:
- 剂量适应性工作流显示,目标覆盖率不显著低于标准方法,除了两个前列腺运动明显的患者.
- 风险器官的中位近最大剂量减少了1.5 Gy,符合性改善 (V95%减少15%).
- 适应计划表现出较低的稳定性,导致目标剂量中位数下降0.5%,特别是较大的运动模式.
结论:
- 在线ART中对遗漏剂量进行后期纠正是可行的,可能降低风险器官的剂量.
- 这种方法提供了更好的符合性,但可能会增加接近最大的目标剂量.
- 减少强度需要仔细考虑,特别是在前列腺运动显著的患者中.
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