CAJ | 학술논문

目的研究多颗125I放射性粒子间剂量衰减规律.方法利用Geant 4软件包进行蒙特卡罗模拟单颗粒子和多颗粒子周围剂量分布,将模拟结果与TG43-U1报告中推荐剂量计算方法所得结果进行对比,并利用实验测得数据验证蒙特卡罗模拟结果.结果单颗粒子周围剂量分布的蒙特卡罗模拟结果与TG43-U1计算和实验结果差值分别在±3％和±5％以内.多颗粒子的蒙特卡罗模拟结果对比TG43-U1线性叠加结果,粒子间剂量衰减为3.8％～ 13.2％,平均剂量衰减为7.2％,实验所得结果与蒙特卡罗模拟结果差值在6％以内.结论空间中存在多颗放射性125I粒子时,由于粒子间的相互影响导致7％左右的剂量衰减,其最大值可超过13％,在人体组织中剂量衰减值会更大.因此,利用TG43-U1方法进行线性叠加计算临床中的剂量分布不够精确.
목적 연구다과125I방사성입자간제량쇠감규률.방법 이용Geant 4연건포진행몽특잡라모의단과입자화다과입자주위제량분포,장모의결과여TG43-U1보고중추천제량계산방법소득결과진행대비,병이용실험측득수거험증몽특잡라모의결과.결과 단과입자주위제량분포적몽특잡라모의결과여TG43-U1계산화실험결과차치분별재±3％화±5％이내.다과입자적몽특잡라모의결과대비TG43-U1선성첩가결과,입자간제량쇠감위3.8％～ 13.2％,평균제량쇠감위7.2％,실험소득결과여몽특잡라모의결과차치재6％이내.결론 공간중존재다과방사성125I입자시,유우입자간적상호영향도치7％좌우적제량쇠감,기최대치가초과13％,재인체조직중제량쇠감치회경대.인차,이용TG43-U1방법진행선성첩가계산림상중적제량분포불구정학.
Objective To investigate the interseed dose attenuation for multiple 125I seeds.Methods Monte Carlo simulation was done by Geant 4 to investigate the dose distribution of single seed and multiple seeds.The results were compared with the dose calculation method from TG43-U1 and examined by experiments.Results The difference of single seed dose distribution between Monte Carlo method and line source model was ± 3％.The difference between Monte Carlo method and experiment result was ± 5％.The interseed dose attenuation of multiple seeds at the interesting points was 3.8％ to 13.2％ and the average interseed dose attenuation was 7.2％.The difference of experiment result and Monte Carlo result was less than 6％.Conclusions The interseed attenuation is about 7％ and the maximum value may be larger than 13％ for multiple seeds.The interseed dose attenuation may be larger in tissue.So it is not accurate to calculate the dose distribution by using TG43-U1.