Monte Carlo法确定^(125)I近距离放射治疗源剂量计算参数

Monte Carlo calculations of the dosimetry parameters for the ^(125)I brachytherapy source

为研究IS12501型125I近距离治疗源的剂量分布特点,依据AAPMTG43U1推荐的剂量计算公式,针对IS12501型125I近距离治疗源,用MonteCarlo方法计算剂量率常数,结果为0.959cGy·h-1·U-1,与TG43U1推荐的值相差2.02%。在0.1~10.0cm范围内计算径向剂量函数,与TG43U1符合较好。计算并补充了各向异性函数的相关数值。在二维平面上给出10cm×10cm的剂量分布。对径向剂量函数和各向异性函数进行拟合,得到实用性较强的经验公式。

For obtaining dose distribution characters the dosimetry parameters of the Model IS12501 ^125I brachytherapy source were calculated using a Monte Carlo simulation based on the dose calculation formalism recommended by AAPM TG43U1. The calculated dose rate constant, 0. 959cGy·h^-1·U^-1 was within 2.02% of the TG43U1 recommended value. The radial dose distribution also agreed with the TG43U1 standard for 0.1 -10. 0 cm from the source. The anisotropy function was also compiled for clinical practice with the far field dose distribution （10 cm × 10 cm）. The results are also used to determine correlations for the radial dose function and the anisotropy function.