【摘要】 目的总散射校正因子Sc,p值是放射治疗处方剂量计算使用的一个重要参数,研究正确获得Sc,p值的方法。方法在射野等中心轴不同深度下对6、15MV能量的光子射线的Sc,p值进行测量。结果Sc,p值随测量深度不同而改变,最大差异为1%～7%。直接测量获得Sc,p值,其测量深度应取处方剂量计算公式中剂量归一点深度。若在其他深度下测量Sc,p值,可用推导公式计算获得Sc,p(fsz.g)。结论欲获得处方剂量公式中使用的Sc,p值,应重视正确的Sc,p值测量深度,可用直接测量法或间接计算法获得。更多还原

【Abstract】 Objective To evaluate the method of measurement of total scatter calibrate factor (Sc,p). Methods To measure the Sc,p at different depths on central axis of 6?MV, 15?MV photon beams through different ways. Results It was found that the measured data of Sc,p changed with the different depths to a range of 1%～7%. Using the direct method, the Sc,p measured depth should be the same as the depth in dose normalization point of the prescription dose. If the Sc,p ( fsz, d) was measured at the other depths, it could be obtained indirectly by the calculation formula. Conclusions The Sc,p in the prescription dose can be obtained either by the direct measure method or the indirect calculation formula. But emphasis should be laid on the proper measure depth.更多还原