摘要
目的：通过对小野的实验测量，探讨能利用现有测量手段且不违背小野剂量学要求的测量方法材料与方法：作者采用零野与４ｃｍ野实测值做图内插的方法确定小野的组织最大剂量比（ＴＭＲ），采用延长测量距离的方法测量总散射因子Ｓｔ；采用胶片剂量学的方法测量离轴分布曲线。结果：给出部分小野的ＴＭＲ值、总散射因子和离轴分布曲线。结论：在不具备微小探头情况下，通过内插获得小野ＴＭＲ的做法不失为一种有效的替代方法。延长ＳＳＤ测定极射因子的做法可行。采用胶片剂量学测量小野剂量分布，可获得较高的分辩力。
urpose:Tolookfortheavailablemethodsofmeasurementinsmallfieldsandtoreporttheresultsofmeasurementofdasimetricparameterof8MVX-rayheamsranginginsizefrom2cmto4cm.MaterialsandMethods:ParametersincludedTMR,totalscattercorrectionfactors(St)andbeamprofilesTheTMRdatainsmallfieldswereobtainedbygraphicalinterpolationfromthezeroareatissuemaximumratioandthemeasuredvaluesforIargerfields,StvaluesofsmallfieldsweremeasuredwiththeextendeddistanceBeamprofilesweremeasuredusingfilmdosimetry.Results:TMRvalues,scattercorrectionfactors(ST)andbeamprofileswhichwasdeterminedinsmallfieldswerereported.Conclusion:TheauthorsconsiderthatgraphicalinterpolationisaneffectiveandsubstitutivemethodforobtainningtheTMRvaluesofsmallfields.Themethodperformedwithextenteddistanceisan;availablemeansformeasurementofStvalues.Filmdosimetryhasexcellentspatialresolutionformeasurementofdosedistributionofsmallfields.
出处
《中华放射肿瘤学杂志》
CSCD
1996年第3期25-28,共4页
Chinese Journal of Radiation Oncology
关键词
小野剂量
总散射因子
DosimetrysmallradiationfieldTotalscattercorrectionfactor
