调强放疗中多叶准直器漏射线对晶体受照剂量的影响  

Impact of MLC Dose Leakage on Lens in Intensity Modulated Radiotherapy

作　　者：张玉海[1] 李月敏[1] 夏火生[1] 王杰[1] 刘亚军[2] 

机构地区：[1]中国人民解放军第309医院放疗科,北京100091 [2]中国人民解放军第309医院医学工程科,北京100091

出　　处：《中国医疗设备》2012年第6期11-13,共3页China Medical Devices

摘　　要：目的研究多叶准直器(MLC)的漏射线及其对晶体的影响。方法使用PTW30013电离室测量MLC的透射因子,并针对5例头部肿瘤患者的调强计划,用PTW31010电离室在Topslane圆柱形模体中,对晶体受照剂量做验证测量。结果 MLC透射因子是1.42%,符合临床要求,5例患者晶体实测剂量均高于计划计算值(P<0.05)。结论调强放疗中MLC的漏散射线,会使晶体实际受照剂量比计划值偏高,在特殊情况下,可以增加对危及器官的剂量验证测量。Objective To study the impact of MLC dose leakage on lens in IMRT.Methods MLC transmission factor was measured with PTW 30013 ion chamber,and the dose verification for lens of 5 IMRT plans were performed in the Topslane cylinder phantom using PTW 31010 ion chamber.Results MLC transmission factor was 1.42% and the measured doses of lens were more than calculated values（P0.05）.Conclusion MLC leakage and scattered ray on lens result in the higher dose than calculated value.It is suggested that the verification measurement of organs at risk should be performed in some cases.

关 键 词：调强放射疗法 多叶准直器 晶体 剂量验证 

分 类 号：R737.9[医药卫生—肿瘤]