Correlation Study of Radiotherapy Plan Parameters on Dose-Validated Plan Gamma Passing Rate
Objective To investigate the correlation between the parameters of head and neck radiotherapy plan and the gamma passing rate of dose-validated plan.Methods A total of 184 head and neck tumor patients treated with radiotherapy in the radiotherapy center,Fujian Cancer Hospital from November 2019 to September 2021 were selected,of which 85 patients were treated with intensity-modulated radio therapy(IMRT)plan and 99 patients were treated with volumetric modulated arc therapy(VMAT)plan.The IMRT and VMAT plans were respectively verified by electronic beam imaging device and ArcCHECK,and different gamma analysis criteria(at 1%/1 mm,2%/2 mm and 3%/3 mm)were verified.The field complexity index of different radiotherapy plans was analyzed,and the correlation between the field complexity index and gamma passing rate was evaluated.Results The gamma passing rate in VMAT plan was lower than that in IMRT plan under the standard of 1%/1 mm,and the difference was statistically significant(P<0.05).The gamma passing rate of VMAT plan and IMRT plan was(90.72±2.84)%and(90.59±5.19)%respectively under 2%/2 mm standard,and the gamma passing rate under 3%/3 mm standard was(97.02±1.71)%and(98.64±1.00)%respectively.The average gamma passing rate of IMRT plan and VMAT plan under 3%/3 mm standard were higher,while the average gamma passing rate under 2%/2 mm standard was decreased,there was no significant difference between the two plans(P>0.05).Among different field complexity indexes,plan normalized MU(PMU),plan averaged beam irregularity(PI),and plan averaged beam modulation(PM)of VMAT plan were higher than those of IMRT plan,while modulation complexity score(MCS)and plan averaged beam area(PA)of VMAT plan were lower than those of IMRT plan,and the differences were statistically significant(P<0.05).Spearman correlation test results showed that under 2%/2 mm standard in IMRT plan,the MCS,PM and gamma passing rate showed weak correlation(|r|<0.4,P<0.05),respectively,while the PMU and gamma passing rate showed a moderate correlation(0.4≤|r|≤0.7,P<0.05).At 3%/3 mm,the PMU,MCS,PM and gamma passing rate showed a moderate correlation(0.4≤|r|≤0.7,P<0.05),respectively.There was no correlation between PA,PI and gamma passing rate(P>0.05).In the VMAT plan,the PMU,MCS,PI,PM and gamma passing rate showed a moderate correlation under 2%/2 mm standard(0.4≤|r|≤0.7,P<0.05),respectively,under 3%/3 mm standard,the of PMU,MCS,PM,PI and gamma passing rate showed a moderate correlation(0.4≤|r|≤0.7,P<0.05),respectively,there was no correlation between PA,PI and gamma passing rate(P>0.05).Conclusion The field complexity index is correlated with the gamma passing rate to varying degrees,and the field complexity index can be adjusted to assist in the design of radiotherapy plan before dose validation.
head and neck tumorsintensity-modulated radio therapyvolumetric modulated arc therapdose validationfield complexity indexgamma passing rate
万方数据
维普
