Joiner M C, Johns H
Radiat Res. 1987 Mar;109(3):456-68.
A further study on the response of the mouse kidney to d(4)-Be neutrons (EN = 2.3 MeV) is described. The results confirm and augment the work published previously by Stewart et al. [Br. J. Radiol. 57, 1009-1021 (1984)]; the present paper includes the data from a "top-up" design of experiment which extends the measurements of neutron RBE (relative to 240 kVp X rays) down to X-ray doses of 0.75 Gy per fraction. The mean RBE for these neutrons increases from 5.8 to 7.3 as X-ray dose per fraction decreases from 3.0 to 1.5 Gy in the kidney. This agrees with the predictions from the linear quadratic (LQ) model, based on the renal response to X-ray doses above 4 Gy per fraction. The mean RBE estimate from a single dose group at 0.75 Gy per fraction of X rays is, however, 3.9. This is below the LQ prediction and may indicate increasing X-ray sensitivity at low doses. Data from this study and from those published previously have been used to determine more accurately the shape of the underlying response to d(4)-Be neutrons; an alpha/beta ratio of 20.5 +/- 3.7 Gy was found. The best value of alpha/beta for X rays determined from these experiments was 3.04 +/- 0.35 Gy, in agreement with previous values.
本文描述了对小鼠肾脏对d(4)-Be中子（等效中子能量EN = 2.3 MeV）反应的进一步研究。结果证实并扩充了Stewart等人先前发表的研究成果[《英国放射学杂志》57, 1009 - 1021 (1984)]；本论文包含了“补充”实验设计的数据，该设计将中子相对生物效应（RBE，相对于240 kVp X射线）的测量范围扩展到了每分次0.75 Gy的X射线剂量。在肾脏中，随着每分次X射线剂量从3.0 Gy降至1.5 Gy，这些中子的平均RBE从5.8增加到7.3。这与基于每分次高于4 Gy的X射线剂量下肾脏反应的线性二次（LQ）模型预测相符。然而，在每分次0.75 Gy X射线的单剂量组中，平均RBE估计值为3.9。这低于LQ模型的预测，可能表明在低剂量下X射线敏感性增加。本研究及先前发表研究的数据已被用于更准确地确定对d(4)-Be中子潜在反应的形状；发现α/β比值为20.5±3.7 Gy。由这些实验确定的X射线的最佳α/β值为3.04±0.35 Gy，与先前的值一致。
