覆盖导向的自适应分成法是指导的
Yoel Samuel Pérez Haas1, Lena Kretzschmar1, Bertrand Pouymayou2
1University Hospital Zurich Clinic for Radiation Oncology, Rämistrasse 100, Zürich, ZH, 8091, SWITZERLAND.
Physics in medicine and biology
|January 30, 2026
概括
覆盖导向的适应分化 (AF) 通过根据瘤和器官的重叠调整每日剂量,改善了针对腹部瘤的MR导向SBRT的目标覆盖率. 具有较大的重叠变异的患者经历了最显著的好处.
科学领域:
- 辐射瘤学 辐射瘤学
- 医学物理 医学物理
- 图像指导疗法是指导图像的疗法.
背景情况:
- 在混合MR-线性加速器上使用磁共振导向放射疗法,可用于具有显著断片运动的腹部/骨盆瘤的立体体辐射疗法 (SBRT).
- 规划目标体积 (PTV) 和剂量限制器官风险 (OAR) 之间的重叠经常需要在SBRT期间妥协PTV覆盖.
- 在线适应性放射治疗 (ART) 策略对于优化在有解剖变异的情况下进行治疗至关重要.
研究的目的:
- 评估重叠导向适应分化 (AF) 在改善腹部/骨盆瘤MR导向SBRT的PTV覆盖率方面的潜在好处.
- 通过利用PTV/OAR重叠的每日变化来管理可变分数剂量来评估通过利用PTV/OAR重叠的每日变化来实现的剂量计增益.
- 确定PTV/OAR重叠变化之间的关系和AF的好处的大小.
主要方法:
- 对58名接受5分数MR导向SBRT治疗的患者进行分析,这些患者对腹部/盆腔瘤进行5分数MR导向SBRT,至少有一分数的PTV-OAR重叠.
- 剂量限制性OARs (肠,十二指肠,胃) 限制在1cc ≤6Gy/分量,导致剂量不足的重叠PTV体积.
- 通过动态编程 (马可夫决策过程) 确定最佳分量剂量,以根据测量的每日重叠量来最大限度地提高PTV覆盖率.
主要成果:
- 在患者之间观察到PTV/OAR重叠体积的实质变化 (标准偏差:0.02 - 5.76cc).
- 在58名患者中,55名患者的PTV覆盖率有好处,平均队列好处为2.93ccGy.
- 在较高的PTV/OAR重叠变化和较大的AF益处之间发现了正相关性,范围从 -4.44到22.42ccGy.
结论:
- 覆盖导向的AF是一种有前途的策略,可以在改善腹部/骨盆SBRT的PTV覆盖率,而不会影响OAR节约.
- 由于许多患者的重叠变化很低,AF的平均队列优势是适度的,但具有显著变化的选定个体受益相当大.
- 需要进一步的前性研究来评估适应分离的临床可行性和益处.
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