中华放射肿瘤学杂志
中華放射腫瘤學雜誌
중화방사종류학잡지
CHINESE JOURNAL OF RADIATION ONCOLOGY
2015年
2期
200-204
,共5页
李光俊%李衍龙%肖江洪%王雪桃%苏晨%柏森
李光俊%李衍龍%肖江洪%王雪桃%囌晨%柏森
리광준%리연룡%초강홍%왕설도%소신%백삼
容积调强弧形疗法%直线加速器%统计过程控制%过程质量控制%到位精度
容積調彊弧形療法%直線加速器%統計過程控製%過程質量控製%到位精度
용적조강호형요법%직선가속기%통계과정공제%과정질량공제%도위정도
Volumetric-modulated arc therapy%linac%Statistical process control%Process quality control%Position accuracy
目的 利用医科达加速器日志文件监测VMAT中加速器日常运行精度,并通过SPC技术实现加速器PQC.方法 提取加速器上每日治疗的日志文件,自动分析加速器执行VMAT弧形野的各参数精度并生成评估报告.分析加速器运行的稳定性和不同病种治疗精度的差异性.通过SPC技术,基于Johnson转换计算各参数的控制限,并绘制控制图实现加速器PQC.结果 连续16 d中VMAT患者76例(主要包括鼻咽癌、宫颈癌、直肠癌、喉癌),共执行VMAT弧形射野2446个.加速器机架角、y和x钨门、MCL叶片到位和剂量输出的平均误差分别为0.49°、0.09 mm和0.38 mm、0.31mm和0.05 MU.病种差异引起剂量输出和机架角误差的变异系数分别为8.10％和4.54％.由SPC技术分析,加速器各参数均处于受控状态,但存在误差大于上控制限的异常点,各参数中机架角处于失控状态的比率(0.45％)最高.结论 利用加速器日志文件能监测加速器运行精度,通过SPC技术绘制控制图,能实现VMAT中加速器日常运行的PQC,是一种经济、有效的日常QA方法.
目的 利用醫科達加速器日誌文件鑑測VMAT中加速器日常運行精度,併通過SPC技術實現加速器PQC.方法 提取加速器上每日治療的日誌文件,自動分析加速器執行VMAT弧形野的各參數精度併生成評估報告.分析加速器運行的穩定性和不同病種治療精度的差異性.通過SPC技術,基于Johnson轉換計算各參數的控製限,併繪製控製圖實現加速器PQC.結果 連續16 d中VMAT患者76例(主要包括鼻嚥癌、宮頸癌、直腸癌、喉癌),共執行VMAT弧形射野2446箇.加速器機架角、y和x鎢門、MCL葉片到位和劑量輸齣的平均誤差分彆為0.49°、0.09 mm和0.38 mm、0.31mm和0.05 MU.病種差異引起劑量輸齣和機架角誤差的變異繫數分彆為8.10％和4.54％.由SPC技術分析,加速器各參數均處于受控狀態,但存在誤差大于上控製限的異常點,各參數中機架角處于失控狀態的比率(0.45％)最高.結論 利用加速器日誌文件能鑑測加速器運行精度,通過SPC技術繪製控製圖,能實現VMAT中加速器日常運行的PQC,是一種經濟、有效的日常QA方法.
목적 이용의과체가속기일지문건감측VMAT중가속기일상운행정도,병통과SPC기술실현가속기PQC.방법 제취가속기상매일치료적일지문건,자동분석가속기집행VMAT호형야적각삼수정도병생성평고보고.분석가속기운행적은정성화불동병충치료정도적차이성.통과SPC기술,기우Johnson전환계산각삼수적공제한,병회제공제도실현가속기PQC.결과 련속16 d중VMAT환자76례(주요포괄비인암、궁경암、직장암、후암),공집행VMAT호형사야2446개.가속기궤가각、y화x오문、MCL협편도위화제량수출적평균오차분별위0.49°、0.09 mm화0.38 mm、0.31mm화0.05 MU.병충차이인기제량수출화궤가각오차적변이계수분별위8.10％화4.54％.유SPC기술분석,가속기각삼수균처우수공상태,단존재오차대우상공제한적이상점,각삼수중궤가각처우실공상태적비솔(0.45％)최고.결론 이용가속기일지문건능감측가속기운행정도,통과SPC기술회제공제도,능실현VMAT중가속기일상운행적PQC,시일충경제、유효적일상QA방법.
Objective To verify the daily delivery accuracy of volumetric-modulated arc therapy (VMAT) and achieve the process quality control (PQC) of linac using statistical process control (SPC)technology.Methods The log files of all treatments were taken out from the linac system.An in-house software which created by Matlab 7.14 was used to analyze the daily parameters accuracy and the mechanism and dose delivery accuracy of the linac for each VMAT,and an daily evaluation report was automatically created for the linac.The stability of the linac and the deviation of the delivery accuracy for various cancer sites were also analyzed.To achieve the process quality control of hnac using SPC technology,the control limit of each parameter was calculated by Johnson alternation and the single value control charts were drawn.Results 76 patients mainly with nasopharyngeal carcinoma,cervical carcinoma,rectal cancer and laryngeal cancer,got the treatment daily with VMAT technology,and a total of 2 446 arcs were delivered by the linac in continuous 16 days.The gantry angle error,y and x collimator position error,MLC leaf position error and dose delivery error were 0.49°,0.09 mm,0.38 mm,0.31 mm,0.05 MU,respectively.Compare to the nasopharynx,uteri,rectal and larynx cancer,it can be seen that the variation factors of dose delivery and gantry angle errors for various cancer sites were higher,which was 8.10％ and 4.54％,respectively.Through the process quality control of the linac,it was found that all the parameters were in control.While some abnormal points arose (the error was greater than UCL),and the ratio of the gantry angle which was out of control (0.45％) was the highest in all parameters.Conclusions linac delivery accuracy could be monitored and verified during the whole VMAT treatment for each patient,and the daily running condition of linac could be monitored.Through the introduction of SPC technology and the control charts,the process quality control of linac in VMAT could be achieved.It is a financial and valid method for the daily quality assurance of linac.
