电子和质子FLASH光束之间的剂量测量和生物对比.
A Almeida1, M Togno2, P Ballesteros-Zebadua3
1Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
概括
电子和质子FLASH疗法在瘤控制和正常组织节约方面表现出类似的疗效. 平均剂量速率,而不是光束类型,似乎对FLASH效应至关重要,维护神经认知功能并激活抗瘤免疫力.
科学领域:
- 辐射瘤学 辐射瘤学
- 临床前研究 临床前研究
- 医学物理 医学物理
背景情况:
- 以超高剂量率 (>40 Gy/s) 为特征的FLASH效应,在使用电子 (eFLASH) 和质子 (pFLASH) 的临床前研究中显示出有希望.
- 没有直接比较eFLASH和pFLASH,以了解它们的相对疗效和潜在机制.
研究的目的:
- 系统地对比由电子束 (eFLASH) 和质子束 (pFLASH) 产生的FLASH效应.
- 评估eFLASH和pFLASH之间的剂量测量一致性和生物结果,包括正常组织节约和瘤控制.
主要方法:
- 在临床前的小鼠模型中,利用电子 (5.5 MeV) 和质子 (170 MeV) 束来产生传统的 (0.1 Gy/s) 和FLASH (≥110 Gy/s) 剂量速率.
- 使用已确定的方法进行了剂量测量对比,并评估了对神经认知能力和瘤反应的生物学影响.
- 质子是在传输模式下交付的.
主要成果:
- 电子和质子束之间的剂量测量差异在剂量速率之间是最小的 (-1.9%至 +2.5%).
- 无论是eFLASH还是pFLASH都保护了正常的大脑功能,照射过的小鼠与对照组相比显示出无法区分的神经认知能力.
- 传统的剂量率 (eCONV,pCONV) 导致认知缺陷,而 eFLASH 和 pFLASH 实现了完整的瘤反应,在重新挑战时激活了抗瘤免疫力.
结论:
- 尽管电子和质子束微观结构存在差异,但剂量标准是可以实现的,这使得有效的FLASH放射治疗成为可能.
- 用电子和质子束实现正常的大脑保护和瘤控制,平均剂量率被确定为FLASH节约效应的关键参数.
- 在高剂量照射后,无论光束类型或剂量速率如何,都观察到全身抗瘤免疫记忆反应.
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