MICROBEAM RADIATION-THERAPY
MICROBEAM RADIATION-THERAPY
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DOI：
10.1118/1.596771
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发表时间：
1992-11-01
期刊：
影响因子：
3.8
通讯作者：
SANDBORG, M
中科院分区：
文献类型：
--
作者：
SLATKIN, DN;SPANNE, P;SANDBORG, M
提出通过将同步加速器产生的X射线平行、紧密间隔的微束阵列多次交叉发射穿过等中心目标来对脑部病变进行放射治疗和放射外科手术，阵列中的每个微束具有几乎等于25微米宽的可调节高度的矩形横截面。根据小鼠大脑中已知的 22-MeV 氘核微束的组织保护以及随后的示例性蒙特卡罗计算得出的以下推论表明，被等中心目标外部的充分间隔的微束阵列中的任何微束致命照射的大脑中的内皮细胞将被由微束间段中的显微镜下连续的、最低限度辐射的内皮细胞再生的内皮细胞所取代脑血管系统。内皮再生将防止非目标实质组织坏死。然而，等角点处的肿瘤和/或非肿瘤目标组织将被多个重叠微束严重耗尽潜在有丝分裂的内皮细胞和实质细胞，从而导致坏死。蒙特卡洛计算使用 50、100 和 150 keV 单色 X 射线模拟直径 16 厘米、长 16 厘米的圆柱形人头模型的微束照射。
It is proposed to carry out radiotherapy and radiosurgery for brain lesions by crossfiring an array of parallel, closely spaced microbeams of synchrotron-generated x rays several times through an isocentric target, each microbeam in the array having an almost-equal-to 25-mum-wide adjustable-height rectangular cross section. The following inferences from the known tissue sparing of 22-MeV deuteron microbeams in the mouse brain and the following exemplary Monte Carlo computations indicate that endothelial cells in the brain that are lethally irradiated by any microbeam in an array of adequately spaced microbeams outside an isocentric target will be replaced by endothelial cells regenerated from microscopically contiguous, minimally irradiated endothelium in intermicrobeam segments of brain vasculature. Endothelial regeneration will prevent necrosis of the nontargeted parenchymal tissue. However, neoplastic and/or nonneoplastic targeted tissues at the isocenter will be so severely depleted of potentially mitotic endothelial and parenchymal cells by multiple overlapping microbeams that necrosis will ensue. The Monte Carlo computations simulate microbeam irradiations of a 16-cm diameter, 16-cm-long cylindrical human head phantom using 50-, 100-, and 150-keV monochromatic x rays.