In this thesis , ga is used to optimize the beam weights of intensity modulated radiation therapy ( imrt ) inverse planning , and 2d and 3d isodose contour as well as dose volume histogram ( dvh ) are used to evaluate the treatment plan 本文应用遗传算法优化逆向调强放疗计划中射束的权重,用二维等剂量线、三维剂量分布和剂量体积直方图来评估计划的优劣。