Richardson R B, Nie H L, Chettle D R
Radiation Biology and Health Physics Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, Canada K0J 1J0.
Radiat Prot Dosimetry. 2007;127(1-4):158-62. doi: 10.1093/rpd/ncm364. Epub 2007 Jul 24.
A Monte Carlo simulation of multiple trabecular bone cavities in adult bone was developed and the absorbed radiation dose factors evaluated for 3H and 14C. The model was developed to assess the dose from radionuclide uptake in quiescent bone, but also the effects of temporal changes in bone turnover by incorporating bone-modelling units (BMU). Absorbed dose fractions were calculated for target regions that include the endosteal layer where radiation-sensitive stem cells in bone marrow are considered to reside preferentially. There were large differences in the absorbed fractions for two types of bone surface, quiescent and forming. Tritium in quiescent bone results in a dose to the endosteum about 20 times that for the same activity in forming bone surface irradiating osteoblasts. When the quiescent bone surface source was extended from an infinitely thin layer to a more realistic 1 microm thick, the tritium absorbed fractions for endosteum and red marrow targets fell by more than 2-fold.
开展了成年骨骼中多个小梁骨腔的蒙特卡罗模拟，并评估了³H和¹⁴C的吸收辐射剂量因子。该模型旨在评估静态骨中放射性核素摄取产生的剂量，同时通过纳入骨建模单元（BMU）来评估骨转换时间变化的影响。计算了包括骨内膜层在内的靶区的吸收剂量分数，骨髓中辐射敏感干细胞被认为优先驻留在该层。静止和成骨两种骨表面的吸收分数存在很大差异。静止骨中的氚对骨内膜产生的剂量约为成骨表面相同活度照射成骨细胞时的20倍。当静止骨表面源从无限薄的层扩展到更实际的1微米厚时，骨内膜和红骨髓靶区的氚吸收分数下降了2倍多。
