中文摘要：

电子调强放射治疗浅表肿瘤优于光子调强放射治疗,但光子调强放射治疗中光子的多叶准直器不适用,需专门的电子多叶准直器EMLC。用Monte Carlo模拟计算研究EMLC叶片的材料、厚度、端面形状和宽度等对剂量的影响。计算结果表明,W比Pb、Fe、Cu更适合做EMLC材料,且厚度2cm时足以挡住大部分电子,并产生相对较少的轫致辐射;直立端面作EMLC叶片端面时会产生较小剂量半影,并在射野边缘有更好平坦度;电子束通过宽度5mm的EMLC叶片比1cm的射野边缘剂量明显增加,但宽度太大不利于准确控制子野形状,因此选择1cm作EMLC叶片宽度较优。

英文摘要：

Modulated electron radiation therapy（MERT）,which delivers conformal dose to shallow tumors and protects distal structures and surrounding tissues,but,the photon multileaf collimator（MLC） is no longer suitable for MERT.In this paper,the PENELOPE code is used to simulate an electron-specific MLC（EMLC） for the optimal choice of the material and geometry of leave.The results demonstrate that tungsten is more suitable for EMLC than lead,iron,copper;and 2 cm thickness is sufficient to resist most of the electrons with relatively less bremsstrahlung;leaf with straight end shape produces less dose penumbra and moreover the width of 1 cm is the most suitable choice for leaf width.