放射治疗外照射的蒙特卡罗计算

Radiotherapy Monte Carlo Calculation of Dose Rate

目的验证MCNP程序计算γ射线的空气比释动能率及周围剂量当量率的准确性。方法将空气比释动能率的理论计算值与模拟值进行对比,以及将周围剂量当量率的实际测量值与模拟值进行对比。结果比释动能率的理论值与模拟值吻合良好,而周围剂量当量率的测量值与模拟值最大误差不超过7.9%,两者呈现与距离平方成反比趋势,随距离增大两者之间的误差变小。结论 MCNP程序可准确模拟空气比释动能率和周围剂量当量率,可应用于制定放疗计划和机房防护等工作中。

Objective To verify the accuracy of the calculation of MCNP ray air kerma rate and ambient dose equivalent rate. Methods The theoretical calculation of air kerma rates was compared with simulated values, and the actual measurement of ambient dose equivalent rate values and simulation values are compared. Results Kerma rate theoretical values and simulation values are in good agreement. The maximum error of the measured value of ambient dose equivalent rate of the analog value of is less than 7.9% and inversely proportional to the square of the distance between the two present trends, error becomes smaller with increasing distance between the two points. Conclusion MCNP program can accurately simulate the air kerma rate and ambient dose equivalent rate,The program can be applied to the development of radiation protection programs and computer room and other work.