放射治疗的效果与模拟定位有着十分重要的关系，从放射治疗学的要求，照射野要把肿瘤及受肿瘤侵犯的邻近组织包括在内，而对正常的器官及组织应加以保护，避免及减少放射性损伤，减轻放疗反应，提高放射治疗的效果。放射治疗通常用两种方法定位。一、源皮距（ＳＳＤ）定位... Radiation therapy and simulation of the positioning of a very important relationship, from the requirements of radiotherapy, the radiation field to the tumor and tumor-infiltrating adjacent tissues included, while the normal organs and tissues should be protected to avoid and reduce Radiation damage, reduce radiation response, improve the effectiveness of radiation therapy. Radiation therapy is usually located in two ways. First, the source distance (SSD) positioning ...