Scalliet P, Landuyt W, van der Schueren E
Laboratory of Experimental Radiotherapy, AZ St Rafaël, Leuven, Belgium.
Radiother Oncol. 1989 Apr;14(4):345-53. doi: 10.1016/0167-8140(89)90147-3.
The effect of continuous irradiation, delivered at four different dose rates (107.6, 14.7, 3.9 and 2 Gy.h-1) has been investigated using the rat cervical spinal cord biological system. The endpoint was the induction of foreleg paralysis at 9 months which corresponds, as has been described before, to white matter necrosis. Paralysis occurring in 50% of the animals was taken as the isoeffect, and the ED50 (radiation dose leading to paralysis in 50% of the animals) was calculated by probit analysis. There was a constant increase in the ED50 with the decrease in the dose rate, resulting from the repair of sublethal damage (SLD) occurring during irradiation. A comparison was made with the previously published results of high dose rate (100-120 Gy.h-1) fractionated irradiations (2, 4 and 10 fractions). alpha/beta (1.6 Gy for the pooled fractionation and dose rate data) and the half-time of SLD repair (82 min) were derived.
利用大鼠颈脊髓生物系统研究了以四种不同剂量率（107.6、14.7、3.9和2 Gy·h⁻¹）进行连续照射的效果。终点指标是9个月时前肢麻痹的诱发情况，如前所述，这对应于白质坏死。将50%的动物出现麻痹作为等效应，并通过概率分析计算ED50（导致50%的动物出现麻痹的辐射剂量）。随着剂量率的降低，ED50持续增加，这是由于照射期间发生的亚致死损伤（SLD）修复所致。将其与先前发表的高剂量率（100 - 120 Gy·h⁻¹）分次照射（2、4和10次分割）的结果进行了比较。得出了α/β（合并分次照射和剂量率数据为1.6 Gy）和SLD修复半衰期（82分钟）。
