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剂量分布验证中分辨率对Gamma通过率的影响
曹午飞, 黄晓延, 孙文钊, 陈利
510060 广州,华南肿瘤学国家重点实验室中山大学肿瘤防治中心放疗科
The impact of resolution to Gamma pass rate in the verification of dose distribution
CAO Wu-fei, HUANG Xiao-yan, SUN Wen-zhao, CHEN Li
Department of Radiation Oncology, Sun Yat-sen University Cancer Center;State Key Laboratory of Oncology in South China;Guangzhou 510060, China Corresponding author:HUANG Xiao-yan, Email:huangxiaoy@sysucc.org.cn
Abstract：Objective To study the impact of the resolution of reference dose distribution and evaluated dose distribution to Gamma rate in the verification of IMRT. Methods Designed four fields, the resolution of dose distribution calculated in water phantom and exported from TPS are 1,2,3,4,5,6 mm. To calculate Gamma index by IBA′s OmniPro-I′mRT software in different sampling resolution. Results When the resolution of evaluated dose distribution was fixed, the change of reference dose distribution′s resolution has little effect on Gamma rate (5% to IMRT field);When the resolution of reference dose distribution was fixed, the Gamma rate increased as the evaluated dose distribution′s resolution (>1 mm) raise (the Gamma rate increase (15.2±6.2)%(t=11.99,P<0.01) and (14.9±5.5)%(t=13.24,P<0.01) while the resolution of evaluated dose distribution changed from 6 mm to 3 mm and from 3 mm to 1 mm respectively). Conclusions To use Gamma method for verification of IMRT, the measured data can be as a reference dose distribution without interpolation;the computed data by TPS can be as a evaluated dose distribution and it is more appropriate for the resolution of 1 mm.
CAO Wu-fei,HUANG Xiao-yan,SUN Wen-zhao et al. The impact of resolution to Gamma pass rate in the verification of dose distribution[J]. Chinese Journal of Radiation Oncology, 2012, 21(2): 172-175.
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2012, Vol. 21 
