CAJ | 학술논문

目的分析放疗中X线的高次散射对剂量计算结果的影响,解决将2次散射光子及高次散射光子对剂量贡献问题修正到1次散射光子散射剂量贡献中的可能性,为建立快速蒙特卡罗剂量计算方法提供支持.方法采用X线与物质的作用截面理论和蒙特卡罗方法计算结果,分析1次、2次和高次散射X线对剂量计算精确度影响相对重要性.结果 ≥2次的高次散射对剂量的影响很小,并且可通过一小的修正系数被修正到1次散射X线的贡献中.结论只追踪原射线和1次散射X线剂量贡献就可获得临床满意的剂量计算精确度,如用蒙特卡罗方法建立1次散射X线散射光子注量角分布和光子平均能量散射角分布模型数据库,将有助于提高临床剂量的蒙特卡罗计算效率.
목적 분석방료중X선적고차산사대제량계산결과적영향,해결장2차산사광자급고차산사광자대제량공헌문제수정도1차산사광자산사제량공헌중적가능성,위건립쾌속몽특잡라제량계산방법제공지지.방법 채용X선여물질적작용절면이론화몽특잡라방법계산결과,분석1차、2차화고차산사X선대제량계산정학도영향상대중요성.결과 ≥2차적고차산사대제량적영향흔소,병차가통과일소적수정계수피수정도1차산사X선적공헌중.결론 지추종원사선화1차산사X선제량공헌취가획득림상만의적제량계산정학도,여용몽특잡라방법건립1차산사X선산사광자주량각분포화광자평균능량산사각분포모형수거고,장유조우제고림상제량적몽특잡라계산효솔.
Objective To analyze the effects of high-order scattered X-ray in dose calculation in radiotherapy,to resolve the problem of correcting the dose contribution of secondary and high-order scattering X-ray to the primary scattered X ray,and to provide a support for photon fast dose calculation method of Monte Carlo.Methods By the theory of cross-section in interaction between X-ray with material and Monte Carlo calculating results,to analysis the relative importance of primary scattered X-ray,secondary and high-order scattered of X-ray in dose calculation.Results The contribution of secondary and high-order scattered X-ray to dose calculation was very small,it can be corrected to the primary scattered X-ray with a correction factor.Conclusions The results show that we can obtain a precise dose calculation for radiotherapy by only to tracking the contribution of primary X-rays and primary scattering X-ray,so,to establishing the database for primary scattering X-ray by Monte Carlo methods is important for fast dose calculation of Monte Carlo method.