混合笔束模型在电子剂量算法中的应用

The application of hybrid\|pencil beam in electron dose calculation\+

将双群模型计算的宽束电子的能量沉积与Fermi Eyges理论的侧向解相结合来构造电子笔束模型 ,即混合笔束模型 .由于混合笔束模型的计算精度和效率较好 ,并且适用范围较大 ,因此 ,混合笔束模型展示了在放射治疗临床应用上的可能性 .在混合笔束模型的基础上 ,改进了混合笔束模型对电子侧向分布的参数计算 .计算结果表明 ,改进的混合笔束模型的精度符合临床应用的要求 ,同时 ,其计算速度非常快 .

Hybrid\|pencil beam model(HPBM),which has been obtained by embedding the bipartition model into Fermi\|Eyges multiple\|scattering theory,shows the potential broad prospect in clinic because of the good calculation accuracy and efficiency.In this paper,we improve the HPBM on calculating the lateral parameter of HPBM,and at the same time, we consider the spectrum of the incident electron beam.Using the improved HPBM,we have calculated the dose distribution for collimated electron beams and compared them with experimental data.The comparison shows that the calculation results agree well with the measurement data.And,the improved HPBM spends much less calculation time.