Jose J G, Ainsworth E J
Radiat Res. 1983 Jun;94(3):513-28.
The cataractogenic potential in mice of heavy charged particles from the Bevalac was examined in relation to dose, linear energy transfer (LET), and time following exposure. BALB/c X C57/b1(6) (CB6F1) mice were exposed to graded single doses (0.05-0.9 Gy) of 570-MeV 40Ar, 425-MeV 20Ne, or 400-MeV 12C particles in the plateau portion of the Bragg curve. Lenses were examined by slit lamp biomicroscopy over a 21-month period. The cataract severity was scored subjectively on a scale of 0 to 4 and compared to the opacities induced by 225-kVp X rays. Both the onset and density of the lens opacities were related to dose, and opacification progressed throughout the entire period of observation. In terms of degree of opacification and rates of onset and progression, the cataractogenic response to 40Ar particles was greater than to either 20Ne or 12C particles. Discrimination between the effects of 20Ne and 12C was possible only at the higher doses employed (0.6 and 0.9 Gy) and only at some observation times. Based on average cataract density at the several observation times, the relative biological effectiveness (RBE) of 40Ar particles is estimated to be 3 to 5 over a cataract score range of about 1.5-3.0 (0.15-0.9 Gy). The RBE for 20Ne and 12C particles is probably somewhat greater than 1.0. The consistency of replicate lens examinations and challenges of the subjective scoring system are discussed.
研究了来自贝伐拉克的重带电粒子对小鼠的致白内障潜力与剂量、线能量转移（LET）以及暴露后的时间之间的关系。将BALB/c X C57/b1(6)（CB6F1）小鼠暴露于布拉格曲线平台部分的570-MeV 40Ar、425-MeV 20Ne或400-MeV 12C粒子的分级单剂量（0.05 - 0.9 Gy）下。在21个月的时间里，通过裂隙灯生物显微镜检查晶状体。晶状体混浊严重程度采用0至4分的主观评分，并与225-kVp X射线诱导的混浊进行比较。晶状体混浊的发生和密度均与剂量有关，并且在整个观察期内混浊都在进展。就混浊程度以及发生和进展速率而言，40Ar粒子的致白内障反应大于20Ne或12C粒子。只有在使用较高剂量（0.6和0.9 Gy）且仅在某些观察时间时，才能区分20Ne和12C的效应。根据几个观察时间点的平均白内障密度，估计在约1.5 - 3.0（0.15 - 0.9 Gy）的白内障评分范围内，40Ar粒子的相对生物效应（RBE）为3至5。20Ne和12C粒子的RBE可能略大于1.0。讨论了重复晶状体检查的一致性以及主观评分系统面临的挑战。
