The research on the factors of effecting with γ passing rate of delivery quality assurance for helical tomotherapy
10.3760/cma.j.issn.1004-4221.2014.03.024
- VernacularTitle:螺旋断层治疗剂量验证γ通过率影响因素研究
- Author:
Qi YUE
;
Jimei DUAN
;
Zhiwei WANG
;
Dan GU
;
Xiumei YANG
;
Rongqing LI
- Publication Type:Journal Article
- Keywords:
ArcCheck;
γ passing rate;
Helical tomotherapy;
Quality assurance
- From:
Chinese Journal of Radiation Oncology
2014;23(3):269-271
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the factors of effecting with yindex analysis of delivery for helical tomotherapy (HT).Methods Measuring γindex with the ArcCheck device for introduced errors in HT.The errors include setup errors in three-dimensional,the gantry angle error,calculating the dose in the phantom,low dose rate.All the results were compared with the 3％/3 mm and 2％/2 mm criteria.The effect of the accuracy in the application of kilovoltage computed tomography (KVCT) and mega-voltage computed tomography (MVCT) images in HT was also analyzed.Paired-t test method was used for difference compared.Results When the errors were introduced to the HT,theγpassing rate of left-right,superior-inferior,anterior-posterior direction dropped 2.7％,7.2％,3.6％ under the 3％/3 mm criteria (P =0.002,0.022,0.007),with 4.6％,15.7 ％,7.6％ under the 2％/2 mm criteria (P =0.001,0.003,0.002) respectively.There was no statistical significance for theγpassing between scanning the ArcCheek phantom with the KVCT and MVCT under the 3％/3 mm and 2％/2 mm criteria (98.6％ vs 98.7％,P =0.859 and 92.7％ vs 92.8％,P =0.984).Conclusions The errors of the setup position and machine paraments can lead to the dose delivery errors in HT,the quality accurance of machine and plan should be enhanced to minimize the dose errors.The results also showed that there is no difference of KVCT and MVCT image on the delivery of HT.
