Cox A B, Keng P C, Lee A C, Lett J T
Int J Radiat Biol Relat Stud Phys Chem Med. 1982 Oct;42(4):355-67. doi: 10.1080/09553008214551291.
As part of a study of progressive radiation effects in normal tissues, the forebrains of New Zealand white rabbits (Oryctolagus cuniculus) (about 6 weeks old) were irradiated locally with single acute doses of 60Co gamma-photons (LET infinity = 0.3 keV/micron), Ne ions (LET infinity = 35 +/- 3 keV/microns) or Ar ions (LET infinity = 90 +/- 5 keV/microns). Other rabbits received fractionated doses of 60Co gamma-photons according to a standard radiotherapeutic protocol. Irradiated rabbits and appropriately aged controls were sacrificed at selected intervals, and whole sagittal sections of their brains were examined for pathological changes. Forebrain damage was scored with subjective indices based on histological differences between the anterior (irradiated) and posterior (unirradiated) regions of the brain. Those indices ranged from zero (no apparent damage) to five (severe infarctions, etc.). At intermediate levels of forebrain damage, the relative biological effectiveness (r.b.e.) of each heavy ion was similar to that found for alopecia and cataractogenesis, and the early expression of the damage was also accelerated as the LET infinity increased. Late deterioration of the forebrain appeared also to be accelerated by increasing LET infinity, although its accurate quantification was not possible because other priorities in the overall experimental design limited systematic sacrifice of the animals.
作为一项关于正常组织渐进性辐射效应研究的一部分，对新西兰白兔（穴兔）（约6周龄）的前脑进行局部照射，单次急性剂量分别为60Coγ光子（无限线性能量转移=0.3keV/微米）、氖离子（无限线性能量转移=35±3keV/微米）或氩离子（无限线性能量转移=90±5keV/微米）。其他兔子按照标准放射治疗方案接受分次剂量的60Coγ光子照射。在选定的时间间隔处死受照射的兔子和适当年龄的对照兔子，并检查其大脑的全矢状切片以观察病理变化。根据大脑前部（受照射）和后部（未受照射）区域之间的组织学差异，以前瞻性指标对前脑损伤进行评分。这些指标范围从0（无明显损伤）到5（严重梗死等）。在前脑损伤的中间水平，每种重离子的相对生物效应（r.b.e.）与脱发和白内障形成的相对生物效应相似，并且随着无限线性能量转移的增加，损伤的早期表现也加速。尽管由于总体实验设计中的其他优先事项限制了对动物的系统性处死，无法对其进行准确量化，但前脑的晚期恶化似乎也因无限线性能量转移的增加而加速。
