Medical physics aspects of the synchrotron radiation therapies: Microbeam radiation therapy (MRT) and synchrotron stereotactic radiotherapy (SSRT)
Medical physics aspects of the synchrotron radiation therapies: Microbeam radiation therapy (MRT) and synchrotron stereotactic radiotherapy (SSRT)
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DOI：
10.1016/j.ejmp.2015.04.016
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发表时间：
2015-09-01
影响因子：
3.4
通讯作者：
Stugu, Bjarne
中科院分区：
文献类型：
--
作者：
Braeuer-Krisch, Elke;Adam, Jean-Francois;Stugu, Bjarne
立体定向同步辐射治疗（SSRT）和微束放射治疗（MRT）都是使用同步辐射治疗脑肿瘤和潜在其他肿瘤的新方法。尽管这些技术的原理不同，但 SSRT 和 MRT 具有某些共同点，并且有可能在未来结合它们的优势。对于 MRT，该技术使用高度准直、准平行的 50 至 600 keV 之间的 X 射线微束阵列。高亮度同步加速器光源的重要特征是非常小的光束发散度和极高的剂量率。最小的光束发散度允许插入所谓的多缝准直器 (MSC)，以产生通常类似于 25-75 微米宽的微平面光束的空间分割光束，这些光束被更宽的（100-400 微米中心到中心 (ctc)）空间分隔，具有非常尖锐的半影。数百Gy的峰值入射剂量对于正常组织来说具有极好的耐受性，同时为啮齿类动物的各种肿瘤模型提供了更高的治疗指数。最近，MRT 相对于正常血管对肿瘤脉管系统的选择性放射脆弱性的假设得到了进一步证实。SSRT（同步加速器立体定向放射治疗）基于肿瘤中高 Z 元素的局部药物摄取，然后用 80 keV 光子进行立体定向照射，以增强仅在肿瘤内的剂量沉积。由于 SSRT 已在 ESRF 处于临床试验阶段，大多数医学物理问题已经得到解决，并简要描述了所实施的解决方案，而 MRT 中的医学物理方面将在本文中进行更详细的讨论。 (C) 2015 年由 Elsevier Ltd 代表意大利医疗协会出版。
Stereotactic Synchrotron Radiotherapy (SSRT) and Microbeam Radiation Therapy (MRT) are both novel approaches to treat brain tumor and potentially other tumors using synchrotron radiation. Although the techniques differ by their principles, SSRT and MRT share certain common aspects with the possibility of combining their advantages in the future. For MRT, the technique uses highly collimated, quasi-parallel arrays of X-ray microbeams between 50 and 600 keV. Important features of highly brilliant Synchrotron sources are a very small beam divergence and an extremely high dose rate. The minimal beam divergence allows the insertion of so called Multi Slit Collimators (MSC) to produce spatially fractionated beams of typically similar to 25-75 micron-wide microplanar beams separated by wider (100-400 microns center-to-center(ctc)) spaces with a very sharp penumbra. Peak entrance doses of several hundreds of Gy are extremely well tolerated by normal tissues and at the same time provide a higher therapeutic index for various tumor models in rodents. The hypothesis of a selective radio-vulnerability of the tumor vasculature versus normal blood vessels by MRT was recently more solidified.SSRT (Synchrotron Stereotactic Radiotherapy) is based on a local drug uptake of high-Z elements in tumors followed by stereotactic irradiation with 80 keV photons to enhance the dose deposition only within the tumor. With SSRT already in its clinical trial stage at the ESRF, most medical physics problems are already solved and the implemented solutions are briefly described, while the medical physics aspects in MRT will be discussed in more detail in this paper. (C) 2015 Published by Elsevier Ltd on behalf of Associazione Italiana di Fisica Medica.