Dosimetric effect of calculation grid size on stereotactic body radiation therapy of lung cancer in helical tomotherapy planning system
10.19745/j.1003-8868.2024029
- VernacularTitle:螺旋断层放射治疗计划系统中不同计算网格对肺癌立体定向放射治疗的剂量学影响
- Author:
Xia-Yu HANG
1
;
Wan-Rong JIANG
;
Yi-Kun LI
;
Jun HU
;
Yan ZHANG
;
Ruo-Qi CAO
;
Nan XU
;
Lei WANG
;
Jin-Da ZHOU
;
Xiang-Dong SUN
Author Information
1. 东部战区总医院放射治疗科,南京 210002
- Keywords:
helical tomotherapy planning system;
non small cell lung cancer;
stereotactic body radiation therapy;
calculation grid;
dosimetric parameter
- From:
Chinese Medical Equipment Journal
2024;45(2):52-57
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the dosimetric effects of different calculation grid size(CGS)in helical tomotherapy(HT)planning system on stereotactic body radiation therapy(SBRT)for non-small cell lung cancer(NSCLC).Methods Nine NSCLC patients receiving radiation therapy for the first time at some hospital from March 2019 to December 2022 were selected as the subjects.SBRT planning was carried out through the HT system with three different CGS plans(Fine,Normal,and Coarse)and the same pitch,modulation factor(MF)and optimization conditions,and the target area indexes of the three CGS plans were compared including conformity index(CI),homogeneity index(HI),dosimetric parameters of the organ at risk(OAR),point dose verification pass rate,treatment time,number of monitor units and Sinograms.SPSS 22.0 was used for statistical analysis.Results For target area HI,there weres significant differences between CGS Fine plan and Coarse plan and between CGS Normal plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan(P＞0.05).For target area CI,there were significant differences between CGS Fine plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan and between CGS Normal plan and Coarse plan(P＞0.05).For OAR dosimetric parameters,CGS Fine plan and Coarse plan had significant differences in heart Dmax and Dmean,esophageal Dmax and Dmean,V5,V20,V30 and Dmean of the whole lung and affected lung,V5 and Dmax of the affected lung and heart V10 and V30(P＜0.05),CGS Normal plan and Coarse plan had obvious differences in esophageal Dmax(P＜0.05),and the remained dosimetric parameters were not statistically significant(P＞0.05).Fine,Normal and Coarse plans had the point dose verifica-tion pass rates being 0.96％,1.50％and 1.77％,respectively.In terms of treatment time and number of monitor units,there were significant differences between Fine plan and Coarse plan(P＜0.05)while no statistical differences were found between Fine and Normal plans and between Normal and Coarse plans(P＞0.05).Sinograms analyses showed Fine plan had evenly distributed segment color gradient,Coarse plan had areas of very dark and very light color gradients and Normal plan was somewhere in between.Conclusion Low CGS has to be used as much as possible to obtain accurate dose distribution during SBRT planning for NSCLC patients,which contributes to the execution of the radiation therapy plan and the prevention of ad-verse effects.[Chinese Medical Equipment Journal,2024,45(2):52-57]
