Methods: Design different MLC field for an irregular field and analyze the relation between MLC field and the irregular field in geometry, and then expose film (for therapy verification) in 6 MV X-ray and 15 MV X-ray and analyze the dose distribution of irregular field s edge.
方法:设计一不规则计划靶区,以MLC叶片与计划靶区的不同相接方式来设计MLC射野,讨论其几何学关系,并以胶片法分析辐射能量在6MV、15MV时射野边缘的剂量学情况。