Monte Carlo计算近距离植入治疗源^(125)I的剂量学参数

Monte carlo calculation for the dosimetric parameters of ^(125)I brachytherapy sources

根据美国医学物理学家协会AAPM推荐的剂量学参数,使用蒙特卡罗代码MCNP计算模型EchoSeed植入治疗粒子源125I的剂量学参数.蒙特卡罗方法分别给出了剂量率常数,径向剂量函数和各向异性函数F(r,θ)等剂量学参数值.MCNP给出125I源在固体水和液态水中的剂量率常数分别为0.937和0.961cGyh-1U-1;并给出各向异性函数常数0.94,这和所报道TLD测量的结果0.95相近.本研究的蒙特卡罗计算结果与同类研究报道的实验测量数据或者蒙特卡罗计算的结果做了比较,发现它们在各自实验工具和计算方法允许误差内非常一致.

This work is dedicated to calculate dosimetrie parameters as recommended by the AAPM, for EchoSeed idione - 125 used for brachytherapy applications. The dosimetric parameters dose constant, radial dose function and anisotropy function, recommended by AAPM are calculated by MCNP Monte Carlo. Dose rate constant for 125I in Solid WaterTM, and liquid water were found to be 0. 937 and 0. 961cGyh-1U-1, respectively. The results also showed anisotropy constant of 0.94 in water which is slightly smaller than that published data （0.95） of TLD measurement. The comparison with the previous study shows that our results of MCNP calculations are good agreement with those measured using TLD and calculated by Monte Carlo method within the uncertainty of the respective methods.