放射外科技术的目的是要耗尽肿瘤细胞,同时保护正常的组织结构 Since there are physical limitations and biolo gical uncertainties involved in this therapy process, a treatment plan needs to account for all those limitations and uncertainties. 因为该治疗过程中涉及到一些人体限制和生物不确定性,所以治疗方案需要考虑所有这些限制和 不确定性 In general, an optimal treatment plan is designed to meet the following requirements 般说来,一个最佳的治疗方案的设计要满足如下要求: 1. Minimize the dose gradient across the target volume. 使通过目标脑瘤体积的剂量梯度为最小 2. Match specified isodose contours to the target volumes. 对目标脑瘤体积要匹配特定的同一剂量的外形轮廓 3. Match specified dose-volume constraints of the target and critical organ. 匹配特定的目标和关键器官的剂量体积限制。 4. Minimize the integral dose to the entire volume of normal tissues or organs 使给正常组织和器官的整体剂量为最小。 Constrain dose to specified normal tissue points below tolerance dose 把给特定正常组织的点位的剂量限制在可耐受剂量之下。 6. Minimize the maximum dose to critical volumes 使给关键脑瘤体积的最大剂量为最小 In gamma unit treatment planning, we have the following constraints 咖玛刀单元治疗方案的限制条件如下 1. Prohibit shots from protruding outside the targe 禁止突出目标脑瘤外部的照射。 2. Prohibit shots from overlapping( to avoid hot spots). 禁止重叠照射(以避免热点)。放射外科技术的目的是要耗尽肿瘤细胞，同时保护正常的组织结构。 Since there are physical limitations and biological uncertainties involved in this therapy process, a treatment plan needs to account for all those limitations and uncertainties. 因为该治疗过程中涉及到一些人体限制和生物不确定性，所以治疗方案需要考虑所有这些限制和 不确定性。 In general, an optimal treatment plan is designed to meet the following requirements. 一般说来，一个最佳的治疗方案的设计要满足如下要求： 1. Minimize the dose gradient across the target volume. 使通过目标脑瘤体积的剂量梯度为最小 2. Match specified isodose contours to the target volumes. 对目标脑瘤体积要匹配特定的同一剂量的外形轮廓。 3. Match specified dose-volume constraints of the target and critical organ. 匹配特定的目标和关键器官的剂量体积限制。 4. Minimize the integral dose to the entire volume of normal tissues or organs. 使给正常组织和器官的整体剂量为最小。 5. Constrain dose to specified normal tissue points below tolerance doses. 把给特定正常组织的点位的剂量限制在可耐受剂量之下。 6. Minimize the maximum dose to critical volumes. 使给关键脑瘤体积的最大剂量为最小。 In gamma unit treatment planning, we have the following constraints: 咖玛刀单元治疗方案的限制条件如下： 1. Prohibit shots from protruding outside the target. 禁止突出目标脑瘤外部的照射。 2. Prohibit shots from overlapping (to avoid hot spots). 禁止重叠照射（以避免热点）