CAJ | 학술논문

目的探讨调强放疗验证中参考分布与被评估分布的分辨率对Gamma分析结果的影响.方法设计4种不同类型的射野,使用TPS在水体模中计算并导出剂量分布的分辨率依次为1、2、3、4、5、6 mm.对不同取样分辨率采用IBA公司OmniPro-I' mRT软件计算Gamma指数.结果当被评估分辨率一定时,参考分辨率的改变对Gamma通过率影响很小(调强射野5％以内)；当参考分辨率一定时,Gamma通过率随被评估分辨率＞1 mm范围内升高有升高趋[从6 mm升高至3 mm通过率升高(15.2±6.2)％(t=11.99,P＜0.01),从3 mm升高至1 mm通过率升高(14.9±5.5)％(t=13.24,P＜0.01)].结论应用Gamma分析方法进行调强放疗剂量分布比较时,可将测量数据作为参考分布,无须插值；将治疗计划系统计算数据作为被评估分布,其分辨率选取1 mm较合适.
목적 탐토조강방료험증중삼고분포여피평고분포적분변솔대Gamma분석결과적영향.방법 설계4충불동류형적사야,사용TPS재수체모중계산병도출제량분포적분변솔의차위1、2、3、4、5、6 mm.대불동취양분변솔채용IBA공사OmniPro-I' mRT연건계산Gamma지수.결과 당피평고분변솔일정시,삼고분변솔적개변대Gamma통과솔영향흔소(조강사야5％이내)；당삼고분변솔일정시,Gamma통과솔수피평고분변솔＞1 mm범위내승고유승고추[종6 mm승고지3 mm통과솔승고(15.2±6.2)％(t=11.99,P＜0.01),종3 mm승고지1 mm통과솔승고(14.9±5.5)％(t=13.24,P＜0.01)].결론 응용Gamma분석방법진행조강방료제량분포비교시,가장측량수거작위삼고분포,무수삽치；장치료계화계통계산수거작위피평고분포,기분변솔선취1 mm교합괄.
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 t0 3 mm and from 3 mm to 1 mm　respectively) .Conclusions To use Camma 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.