Sakamoto K, Miyamoto M, Watabe N
Gan To Kagaku Ryoho. 1987 May;14(5 Pt 2):1545-9.
Total body irradiation (TBI) is considered to bring about an immunosuppressive effect on an organism, on the basis of data obtained from sublethal doses of TBI. However, there are no data on how low-dose TBI affects an organism. Over the last five years, we have been studying the effects of low-dose TBI on normal or tumor-bearing mice and the immunological background of these effects. In experimental studies, an increase in the TD50 value (the number of cells required for a tumor incidence of 50%) in mice exposed to 10 rad was recognized and showed a remarkable increase at 6 hours to 15 hours after irradiation. TBI of 10 rad also showed an enhancement effect on tumor cell killing when given 12 hours before local tumor irradiation. In order to clarify the mechanism of this kind of effect, some immunological studies were performed using several immunological procedures, and the results suggested that 10 rad of TBI caused increasing tumor immunity in irradiated mice. Clinical trials in some patients with advanced tumors are now being undertaken on the basis of these experimental data, and the effect of TBI on tumor control appears promising, although it is too early to draw conclusions.
基于从亚致死剂量全身照射（TBI）获得的数据，全身照射被认为会对机体产生免疫抑制作用。然而，关于低剂量TBI如何影响机体的数据却尚无报道。在过去五年中，我们一直在研究低剂量TBI对正常或荷瘤小鼠的影响以及这些影响的免疫学背景。在实验研究中，我们发现接受10拉德照射的小鼠的TD50值（肿瘤发生率达到50%所需的细胞数量）有所增加，并且在照射后6小时至15小时出现显著上升。当在局部肿瘤照射前12小时给予10拉德的TBI时，它对肿瘤细胞杀伤也显示出增强作用。为了阐明这种效应的机制，我们使用了几种免疫学方法进行了一些免疫学研究，结果表明10拉德的TBI可使受照射小鼠的肿瘤免疫力增强。目前正基于这些实验数据对一些晚期肿瘤患者进行临床试验，尽管现在得出结论还为时过早，但TBI对肿瘤控制的效果似乎很有前景。
