Zywietz F, Jung H, Hess A, Franke H D
Int J Radiat Biol Relat Stud Phys Chem Med. 1979 Jan;35(1):63-72. doi: 10.1080/09553007914550051.
At the Hamburg-Eppendorf Hospital neutron facilities the relative biological effectiveness (r.b.e.) of d,T-neutrons was determined with respect to survival of mouse intestinal crypts. (CBA/Rij x C57BL/Rij)F1 mice were irradiated to the whole body at different depths inside a tissue-equivalent phantom. Irradiations were carried out with a collimated neutron beam at about 6 rad/min given in single doses ranging from 450 to 1000 rad. For reference, gamma-rays from a 60Co therapy unit were used. The number of surviving intestinal crypts per circumference of the jejunum was determined 3 1/2 days after irradiation according to the method of Withers and Elkind. The number of surviving stem cells was calculated on the basis of Poisson statistics. The doses necessary to reduce survival to ten crypt stem cells per circumference amounted to 689 +/- 19 rad for neutrons and 1449 +/- 29 rad for 60Co gamma-rays. From these figures an r.b.e. of 2 . 1 +/- 0 . 1 is obtained. Measurements at different depths in the phantom did not show any variation of r.b.e. with depth along the axis of the neutron beam.
在汉堡-埃彭多夫医院的中子设施中，针对小鼠肠隐窝的存活情况测定了d，T中子的相对生物效应（r.b.e.）。将（CBA/Rij×C57BL/Rij）F1小鼠在组织等效模型内的不同深度进行全身照射。使用准直中子束以约6拉德/分钟的剂量进行照射，单次剂量范围为450至1000拉德。作为对照，使用了60Co治疗单元产生的γ射线。根据威瑟斯和埃尔金德的方法，在照射后3.5天测定空肠每圆周存活的肠隐窝数量。基于泊松统计计算存活干细胞的数量。将存活数量降低至每圆周十个隐窝干细胞所需的剂量，中子为689±19拉德，60Coγ射线为1449±29拉德。据此得出r.b.e.为2.1±0.1。在模型内不同深度的测量未显示r.b.e.沿中子束轴随深度有任何变化。
