SUBACUTE NEUROPATHOLOGICAL EFFECTS OF MICROPLANAR BEAMS OF X-RAYS FROM A SYNCHROTRON WIGGLER
SUBACUTE NEUROPATHOLOGICAL EFFECTS OF MICROPLANAR BEAMS OF X-RAYS FROM A SYNCHROTRON WIGGLER
复制标题
DOI：
10.1073/pnas.92.19.8783
复制
发表时间：
1995-09-12
影响因子：
11.1
通讯作者：
LAISSUE, JA
中科院分区：
文献类型：
--
作者：
SLATKIN, DN;SPANNE, P;LAISSUE, JA
微平面束放射疗法已被提议通过使用一系列快速暴露于平行 X 射线束阵列来治疗脑肿瘤，每个束具有均匀的微观厚度和宏观宽度（即微平面）。 36 只大鼠正面暴露于直立的 4 毫米高、20 或 37 微米宽的光束或水平的 7 毫米宽、42 微米高的光束，大部分为 32 至 126 keV，来自布鲁克海文国家实验室国家同步加速器光源的 X17 摆动器的最小发散 X 射线。头部的平行切片在中心间隔 75 或 200 μm，以每秒 310-650 戈瑞 (Gy) 的速度连续曝光，直到每个皮肤入口吸收剂量达到 312、625、1250、2500、5000 或 10,000 Gy。 2周或1个月后对大鼠进行安乐死，两只具有10,000-Gy入口切片的大鼠出现脑组织坏死，所有其他10,000-和5000-Gy入口切片以及一些2500-和1250-Gy入口切片显示神经元和星形细胞核及其周核的损失。在入口吸收剂量小于或等于 5000 Gy 的任何大鼠中，没有明显的其他类型的脑损伤，所有 312 和 625 Gy 入口切片内和之间的脑组织均表现正常。这种不同寻常的抗坏死能力是微平面束放射治疗脑肿瘤的基本原理的核心。
Microplanar beam radiation therapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and macroscopic breadth (i.e., microplanar). Thirty-six rats were exposed head-on either to an upright 4 mm-high, 20- or 37-mu m-wide beam or to a horizontal 7-mm-wide, 42-mu m-high beam of mostly 32- to 126-keV, minimally divergent x-rays from the X17 wiggler at the National Synchrotron Light Source at Brookhaven National Laboratory. Parallel slices of the head, separated at either 75 or 200 mu m on center, were exposed sequentially at 310-650 grays (Gy) per second until each skin-entrance absorbed dose reached 312, 625, 1250, 2500, 5000, or 10,000 Gy. The rats were euthanized 2 weeks or 1 month later, Two rats with 10,000-Gy-entrance slices developed brain tissue necrosis, All the other 10,000- and 5000-Gy-entrance slices and some of the 2500- and 1250-Gy-entrance slices showed loss of neuronal and astrocytic nuclei and their perikarya. No other kind of brain damage was evident histologically in any rat with entrance absorbed doses less than or equal to 5000 Gy, Brain tissues in and between all the 312- and 625-Gy-entrance slices appeared normal. This unusual resistance to necrosis is central to the rationale of microplanar beam radiation therapy for brain tumors.