Sätherberg A, Karlsson M, Karlsson M
Department of Radiation Physics, Umeå University, Sweden.
Phys Med Biol. 1996 Dec;41(12):2687-94. doi: 10.1088/0031-9155/41/12/008.
The output factor used for monitor unit determination in radiotherapy can be divided into two factors: the head scatter factor and the phantom scatter factor. Theoretical and experimental phantom scatter factors have been compared for different beam qualities between 4 MV and 50 MV and field sizes from 5 cm x 5 cm to 30 cm x 30 cm. The theoretical data were obtained through a convolution method based on Monte Carlo calculated energy spectra and dose kernels. The calculations have been performed both for accelerators with a rather large energy variation within the field and for accelerators with a constant energy distribution in the field. Deviations between theoretical and experimental data were found to be less than 1%.
机头散射因子和模体散射因子。已比较了4兆伏至50兆伏不同射束质和5厘米×5厘米至30厘米×30厘米射野尺寸下的理论和实验模体散射因子。理论数据是通过基于蒙特卡洛计算的能谱和剂量核的卷积方法获得的。已针对射野内能量变化相当大的加速器以及射野内能量分布恒定的加速器进行了计算。发现理论数据与实验数据之间的偏差小于1%。
