中华放射医学与防护杂志
中華放射醫學與防護雜誌
중화방사의학여방호잡지
Chinese Journal of Radiological Medicine and Protection
2014年
6期
427-430
,共4页
邢晓汾%褚薛刚%崔桐%郑旭亮%郭瑞嵩
邢曉汾%褚薛剛%崔桐%鄭旭亮%郭瑞嵩
형효분%저설강%최동%정욱량%곽서숭
调强放疗%质量保证%三维剂量验证%剂量学
調彊放療%質量保證%三維劑量驗證%劑量學
조강방료%질량보증%삼유제량험증%제량학
Intensity-modulated radiotherapy%Quality assure%Three-dimensional dose verification%Dosimetry
目的 测试三维剂量验证系统CompassR测量重建及独立计算剂量的精度,评估其临床应用可行性.方法 设计一系列宽度分别为2、1、0.5 cm的条纹状射野,并选取11例肺部调强放疗(IMRT)计划,使用胶片和电离室对被测系统的平面剂量分布和特定点绝对剂量进行验证测试;使用CompassR对IMRT模体计划做基于解剖信息的三维剂量验证,验证体积γ通过率、平均剂量偏差等参数.结果 条纹状射野测试,与胶片测量相比,被测系统重建和计算剂量γ通过率大于90％(选用3％/3 mm、2％/2 mm标准),宽度为0.5 cm射野在半影区内γ通过率略差,被测系统重建和计算剂量曲线与胶片测量的曲线最大偏离分别3.21％和2.70％;IMRT计划特定点绝对剂量偏差在3％以内,最大偏差发生在肺部,IMRT计划等中心平面测量重建与胶片测量的γ通过率平均为(94.65±1.93)％(选用3％/3 mm标准);三维剂量验证结果,靶区及危及器官的体积γ通过率均大于90％,平均剂量的偏差＜1％.结论 测试系统剂量精度可满足IMRT计划验证要求,并能给出与患者解剖结构相关的体积剂量误差与位置误差的信息,有利于评估其对临床的影响.
目的 測試三維劑量驗證繫統CompassR測量重建及獨立計算劑量的精度,評估其臨床應用可行性.方法 設計一繫列寬度分彆為2、1、0.5 cm的條紋狀射野,併選取11例肺部調彊放療(IMRT)計劃,使用膠片和電離室對被測繫統的平麵劑量分佈和特定點絕對劑量進行驗證測試;使用CompassR對IMRT模體計劃做基于解剖信息的三維劑量驗證,驗證體積γ通過率、平均劑量偏差等參數.結果 條紋狀射野測試,與膠片測量相比,被測繫統重建和計算劑量γ通過率大于90％(選用3％/3 mm、2％/2 mm標準),寬度為0.5 cm射野在半影區內γ通過率略差,被測繫統重建和計算劑量麯線與膠片測量的麯線最大偏離分彆3.21％和2.70％;IMRT計劃特定點絕對劑量偏差在3％以內,最大偏差髮生在肺部,IMRT計劃等中心平麵測量重建與膠片測量的γ通過率平均為(94.65±1.93)％(選用3％/3 mm標準);三維劑量驗證結果,靶區及危及器官的體積γ通過率均大于90％,平均劑量的偏差＜1％.結論 測試繫統劑量精度可滿足IMRT計劃驗證要求,併能給齣與患者解剖結構相關的體積劑量誤差與位置誤差的信息,有利于評估其對臨床的影響.
목적 측시삼유제량험증계통CompassR측량중건급독립계산제량적정도,평고기림상응용가행성.방법 설계일계렬관도분별위2、1、0.5 cm적조문상사야,병선취11례폐부조강방료(IMRT)계화,사용효편화전리실대피측계통적평면제량분포화특정점절대제량진행험증측시;사용CompassR대IMRT모체계화주기우해부신식적삼유제량험증,험증체적γ통과솔、평균제량편차등삼수.결과 조문상사야측시,여효편측량상비,피측계통중건화계산제량γ통과솔대우90％(선용3％/3 mm、2％/2 mm표준),관도위0.5 cm사야재반영구내γ통과솔략차,피측계통중건화계산제량곡선여효편측량적곡선최대편리분별3.21％화2.70％;IMRT계화특정점절대제량편차재3％이내,최대편차발생재폐부,IMRT계화등중심평면측량중건여효편측량적γ통과솔평균위(94.65±1.93)％(선용3％/3 mm표준);삼유제량험증결과,파구급위급기관적체적γ통과솔균대우90％,평균제량적편차＜1％.결론 측시계통제량정도가만족IMRT계화험증요구,병능급출여환자해부결구상관적체적제량오차여위치오차적신식,유리우평고기대림상적영향.
Objective To test the accuracy of a three-dimensional dose verification system CompassR,which reconstructing dose distribution based on measurements and independent dose calculation,and to evaluate the feasibility of its application in clinical intensity-modulated radiotherapy (IMRT) quality assure.Methods A set of square-wave chart patterns of 2 cm,1 cm and 0.5 cm gaps was designed and 11 completed IMRT lung plans were selected for the test.EDR2 film and the ionization chamber were used for test and verifying of plane dose distribution and some special points dose of CompassR.The IMRT phantom plans were verified by CompassR with three-dimension based on anatomical information.Parameters including the volume γ pass rate and the average dose deviation were tested using dose volume histograms.Results In square-wave chart patterns test,the dose distribution reconstructed and calculated by CompassR coincided with the measurement using film.The γ pass rates (3％/3 mm,2％/2 mm) exceeded 90％.When the width of field is 0.5 cm,the γ pass rate was a little lower on account of the penumbra zone.Compared to the dose distribution profile which was measured by film,the maximum deviations of the dose distribution profile which was reconstructed and calculated by CompassR were 3.21％ and 2.70％.The absolute dose deviation of specific point in the IMRT plans was less than 3％,the maximum deviation occurred in the lung.Compared to film,the averageγpass rates on the isocenter plain in IMRT plan were (94.65 + 1.93)％ (3％/3 mm) which was reconstructed by CompassR.In three-dimensional dose verification,the volume γ pass rates of targets and risk organs were not less than 90％,and the deviation of average dose was less than 1％.Conclusions Accuracy of the tested system satisfies the demand of IMRT dose verification.CompassR could provide information of volumetric dosimetry and anatomical location of dose error,which is benefit for evaluating the clinical value of verification result.
