不同准直器角度对鼻咽癌旋转调强计划剂量验证的影响  

Effects of Different Collimator Angles on the Dose Verification of Volumetric Modulated Arc Therapy for Nasopharyngeal Carcinoma

作　　者：刘鲁根 郑波 乔浩 曾建伦 汤江林 LIU Lugen;ZHENG Bo;QIAO Hao(Pingxiang People's Hospital,Pingxiang,337000)

机构地区：[1]江西省萍乡市人民医院,337000

出　　处：《实用癌症杂志》2022年第12期1980-1982,共3页The Practical Journal of Cancer

基　　金：萍乡市科技计划项目(萍科社验字【2020】54号)。

摘　　要：目的探讨在鼻咽癌容积旋转调强(VMAT)计划中,不同准直器角度对计划剂量验证的影响。方法收集55例鼻咽癌放疗患者进行研究,每例患者分别设计10个计划。准直器角度分别设定为0°/0°、5°/355°、10°/350°、15°/345°、20°/340°、25°/335°、30°/330°、35°/325°、40°/320°、45°/315°(双全弧照射),并对所有计划用Matrixx二维矩阵进行剂量验证,验证结果实行γ分析,采用3 mm,3%标准,并分析各组计划的γ通过率,大于95%为合格。结果准直器角度在20°时,剂量验证γ通过率最高,当角度大于30°和小于20°时,通过率开始降低,且0°时最低。通过比较分析,最优通过率(99.1±0.38)%(角度为20°)和最差通过率(96.8±0.58)%(角度为0°)具有明显差异,有统计学意义(P<0.05)。结论基于本研究的结果,准直器角度的不同对计划γ通过率具有明显的影响。在鼻咽癌VMAT计划设计过程中,准直器角度为20°时,γ通过率最优。此外,结合对其它剂量学参数的影响,准直器角度在15°~25°范围内计划质量较为理想。Objective To investigate the effect of different collimator angles on the dose verification in nasopharyngeal carcinoma volumetric modulated arc therapy(VMAT).Methods 55 patients with nasopharyngeal carcinoma radiotherapy were selected and 10 VMAT plans with collimator angles of 0°/0°,5°/355°,10°/350°,15°/345°,20°/340°,25°/335°,30°/330°,35°/325°,40°/320°,45°/315°were designed for each patient using the same planning objectives.The dose verification was performed for each plan by using Matrixx.The result was analyzed by the means ofγpassing rate with 3mm,3%standard.Theγpassing rate over 95%was considered as an effective result.Results The results indicated thatγpassing rate was statistically maximum when the collimator angle was selected as 20°.With the collimator angle more than 30°and less than 20°,theγpassing rate began to decline,and the worstγpassing rate occurred at 0°.Through comparative analysis,there was an huge difference between the highestγpassing rate(99.1±0.38)%(at 20°)and the lowest passing rate(96.8±0.58)%(at 0°).The VMAT plans was statistically significant(P<0.05).Conclusion Based on the experimental result,the difference of the collimator angle has an obvious influence on theγpassing rate.The angle of collimator with 20 is suggested to design VMAT plan for nasopharyngeal carcinoma.Therefore,the highestγpassing rate can be reached.Considering the influence of the angle of collimator on other dosimetric parameters,the most favorable collimator angle can be achieved with the angle from 15°to 25°.

关 键 词：准直器角度 旋转调强 鼻咽癌 剂量验证 

分 类 号：R739.63[医药卫生—肿瘤]