MCNP5与EGSnrc比较计算125I种子源剂量参数

Determination of dosimetric parameters for ^(125)I seed source using MCNP5 and EGSnrc MC codes

根据AAPM TG43U1的推荐,使用MCNP5与EGSnrc两种蒙特卡罗程序计算6711型125I种子源剂量计算参数,并将两者计算结果和AAPM推荐值比较,得到相对偏差结果如下:剂量率常数,MCNP5为0.62%,EGSnrc为2.07%;径向剂量函数,MNCP5为0.15%-5.12%,EGSnrc为0%-2.18%。两者计算结果均与推荐值符合得很好,而EGSnrc的计算结果更具优势。

Background： Seed source has become a popular treatment option in the management of various tumors, particularly in the prostate. Purpose： The aim is to develop accurate and reliable dosimetric parameters that could be used to measure the dose delivered to organs at risk. Methods： Dosimetric parameters （dose rate constant, radial dose function and anisotropy function） of model 6711 125I seed source were calculated with MCNP5 and EGSnrc MC codes following AAPM TG43U1 recommendations. Results： The two results were compared with the relative data recommend by AAPM TG43U1, and the data were as follows： dose rate constant with MCNP5 was in agreement with 0.62%, while that with EGSnrc was 2.07%; radial dose function with MCNP5 was within 0.15%-5.12%, while that with EGSnrc was within 0%-2.48%. Conelusion： The results of two MC codes are in accordance with the recommendations. But that with EGSnrc MC code is better.