Jirtle R L, DeLuca P M, Hinshaw W M, Gould M N
Int J Radiat Oncol Biol Phys. 1984 Jun;10(6):895-9. doi: 10.1016/0360-3016(84)90392-4.
The purpose of these experiments was to estimate the RBE of neutrons for parenchymal hepatocytes as a function of neutron dose and to determine the ability of liver cells to repair potentially lethal damage (PLD) after neutron exposure. Hepatocyte reproductive survival was used as the biological end point in these studies and hepatocyte survival was determined with an in vivo transplantation clonogenic assay system. The 14.3 MeV neutrons were generated by a D-T reaction at the University of Wisconsin's gas target neutron source. The average neutron dose rate was 20 cGy/min. The estimated survival data for neutron exposed hepatocytes were best described by a single hit-single target model (i.e., n = 1.0) with a D0 = 170 cGy. In contrast to the results obtained with 60Co, hepatocytes exposed to neutrons are unable to repair PLD. The RBE value, when the reproductive survival was estimated 30 min after radiation exposure, is independent of neutron dose and equal to 1.6 +/- 0.1. In contrast, when the reproductive survival was estimated 24 hrs after radiation exposure, the RBE was found to increase with decreasing neutron dose and equal 4.2 +/- 0.5 at 50 cGy.
这些实验的目的是评估中子对实质肝细胞的相对生物效应（RBE）与中子剂量的关系，并确定肝细胞在中子照射后修复潜在致死性损伤（PLD）的能力。在这些研究中，肝细胞繁殖存活被用作生物学终点，肝细胞存活通过体内移植克隆形成测定系统来确定。14.3 MeV的中子由威斯康星大学气体靶中子源的D-T反应产生。平均中子剂量率为20 cGy/分钟。中子照射肝细胞的估计存活数据最好用单 hit-单靶模型（即n = 1.0）来描述，D0 = 170 cGy。与60Co照射的结果相反，中子照射的肝细胞无法修复PLD。当在辐射暴露后30分钟估计繁殖存活时，RBE值与中子剂量无关，等于1.6±0.1。相反，当在辐射暴露后24小时估计繁殖存活时，发现RBE随着中子剂量的降低而增加，在50 cGy时等于4.2±0.5。
