摘要
目的探讨适形铅挡块遮挡照射野外边缘情况下对表面辐射剂量的影响。方法将金属氧化物半导体场效应管（MOSFET）剂量探测器探头沿垂直于野边缘的直线布置在照射野外边缘,用不同宽度的低熔点适形铅块去屏蔽照射野外边缘,比较遮挡不同宽度铅块后与不遮挡时边缘区的剂量变化。结果遮挡适形铅挡块后与没有遮挡铅块比较,照射野边缘表面0～2mm内剂量跌落15%~20%,差异有高度统计学意义（P〈0.01）;遮挡适形铅块后与不遮挡铅块比较,照射野外2～10mm区域,剂量变化不显著,差异无统计学意义（P〉0.05）。结论用低熔点铅挡块遮挡照射野既可形成适形放疗效果而且可降底照射野外边缘辐射剂量,有利于保护照射野外正常组织。
Objective To study the effect of dose conformal lead block sheilding on adjacent area outside radiation field. Mehtods Metal oxide-sillicon semiconductor field effect transistor （MOSFET） probes were laid vertically on the edge of the radiation field intensively. Low melting-point alloy confor- mal lead blocks of different thickness were used to shield the adjacent area of the radiation field. MOS- FET probes were individually measured under different conditions. Results Comparing shielding con- formal lead blocks, with no lead block shielding the surface dose decreased 15%-20%, within 0~2 mm out of the radiation field. There was significant difference （P〈0.01）. However, there was no significant dose change exceeding 2mm （from 2 to 10 mm） out of the radiation field （P〉0.05）, comparing shielding conformal lead blocks with no lead block used. Conclusion Conformal lead block decreases the sur- face dose out of the edge of radiation field and can protect the adjacent normal tissues.
出处
《苏州大学学报（医学版）》
CAS
北大核心
2009年第4期675-677,共3页
Suzhou University Journal of Medical Science
关键词
辐射剂量
照射野外
适形铅块
radiation dose
outside radiation field
conformal lead block
