聚合器角度旋转和不同角度组合在体积调节的基于弧度的立体辐射手术中的意义,用于单个大脑转移的5mm叶子宽度多叶聚合器
Kazuhiro Ohtakara1,2, Kojiro Suzuki2
1Department of Radiation Oncology, Kainan Hospital Aichi Prefectural Welfare Federation of Agricultural Cooperatives, Yatomi, JPN.
Cureus
|February 25, 2025
概括
多叶合器 (MLC) 角度旋转改善了单个大脑转移的体积调制弧 (VMA) 立体性放射性手术 (SRS) 的剂量分配. 虽然没有旋转的VMA是非劣势的,但为高效的辐射,建议设置45o的固定角度.
科学领域:
- 辐射瘤学 辐射瘤学
- 医学物理 医学物理
- 神经外科 神经外科
背景情况:
- 多叶聚合器 (MLC) 角度旋转对于在多重脑转移 (BMs) 的立体射线手术 (SRS) 中最大限度地减少大脑剂量至关重要.
- 在某些 linac 系统中存在 MLC 旋转和非共平面弧 (NCA) 范围的限制.
- 对于单个BM的SRS中MLC角度旋转的意义仍然不清楚.
研究的目的:
- 调查MLC角度旋转及其SRS组合对单个BMs的意义.
- 为了评估不同MLC角度配置的体积调制弧 (VMA).
- 为了比较基于VMA的SRS与固定和变化的MLC角度的规划参数.
主要方法:
- 包括27名患者的30个单个脑转移 (BM).
- 基于VMA的四个SRS计划被创建用于每个GTV使用敏捷性MLC:所有0o (All_0),所有90o (All_90),所有45o (All_45) 和一个组合 (0_45_90).
- 处方剂量:43,000 Gy分为五部分,用DV-0.01 cc或D95%进行评估.
主要成果:
- 在四个MLC角度组 (弗里德曼测试) 之间,整体参数没有显著差异.
- 在GTV覆盖率 (DeIIV),边界剂量和辐射异位剂量 (IIV) 泄露量 (Wilcoxon签名等级测试) 中观察到显著差异.
- All_45显示了剂量分配的最佳趋势; 0_45_90具有最小的规定的同剂量体积 (PIV) 泄漏.
结论:
- MLC 角度旋转和组合可以改善单个 BM 基于 VMA 的 SRS 中的剂量分配.
- 最佳的MLC旋转角度因病变而异;没有旋转的VMA (All_0) 提供非劣势的剂量分配.
- 为了有效照射,建议使用45o的固定MLC角度;对于病变特定的标准,需要进一步研究.
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