Werner B L, Khan F M, Deibel F C
Med Phys. 1982 Mar-Apr;9(2):180-7. doi: 10.1118/1.595157.
The Fermi-Eyges theory of electron scattering overestimates the scattering of electron beams used in radiation therapy. The reason for this overestimate is the neglect of the loss of electrons which are scattered into highly oblique paths and removed from the beam at relatively shallow depths. A modification of Eyges' solution to Fermi's equation is presented to take this loss of electrons into account. Equations for the calculation of isodose distributions for any medium using pencil beams are developed. Experimental confirmation is presented for electron beams of 13 and 18 MeV in homogeneous water, polystyrene, Lucite, and aluminum phantoms.
费米-艾格斯电子散射理论高估了放射治疗中使用的电子束的散射。这种高估的原因是忽略了散射到高倾斜路径并在相对较浅深度从束流中移除的电子损失。本文提出了对艾格斯对费米方程解的修正，以考虑这种电子损失。推导了使用笔形束计算任何介质等剂量分布的方程。给出了在均匀水、聚苯乙烯、有机玻璃和铝模体中13和18兆电子伏电子束的实验验证。
