CAJ | 학술논문

目的利用一种二维半导体探测器阵列(2D-DA)对调强放射治疗(IMRT)进行多角度合成剂量验证,探索更真实地反映IMRT执行剂量分布精度的方法.方法在2D-DA上附加等效水模体,对27例患者的IMRT计划分别进行单一机架角度合成(SGAC)和多机架角度合成(MGAC)的剂量分布验证测量,比较分析两种方法的测量结果.结果 (1)选择合适摆位使2D-DA的探测器平面不与任一调强射野的中心轴重合时,MGAC测量与SGAC测量的计划验证通过率(通过标准:r值3 mm/3%)分别为94.81%±3.80%和94.56%±4.28%,两者没有明显统计学差异(t=-0.213,P＞0.05).(2)当IMRT计划的部分射野中心轴与探测器平面重合时,MGAC验证测量的通过率为79.72%±12.77%.结论在附加了等效水模体条件下,使用二维半导体探测器阵列进行MGAC与SGAC验证的通过率没有差异.MGAC验证结果更有利于发现IMRT计划执行误差实际大小、位置,以及对临床治疗影响评估,但应在验证测量时避免探测器平面与射野中心轴重合.
목적 이용일충이유반도체탐측기진렬(2D-DA)대조강방사치료(IMRT)진행다각도합성제량험증,탐색경진실지반영IMRT집행제량분포정도적방법.방법 재2D-DA상부가등효수모체,대27례환자적IMRT계화분별진행단일궤가각도합성(SGAC)화다궤가각도합성(MGAC)적제량분포험증측량,비교분석량충방법적측량결과.결과 (1)선택합괄파위사2D-DA적탐측기평면불여임일조강사야적중심축중합시,MGAC측량여SGAC측량적계화험증통과솔(통과표준:r치3 mm/3%)분별위94.81%±3.80%화94.56%±4.28%,량자몰유명현통계학차이(t=-0.213,P＞0.05).(2)당IMRT계화적부분사야중심축여탐측기평면중합시,MGAC험증측량적통과솔위79.72%±12.77%.결론 재부가료등효수모체조건하,사용이유반도체탐측기진렬진행MGAC여SGAC험증적통과솔몰유차이.MGAC험증결과경유리우발현IMRT계화집행오차실제대소、위치,이급대림상치료영향평고,단응재험증측량시피면탐측기평면여사야중심축중합.
Objective In order to explore the ways of reflecting the dose distribution in the implementation of the of IMRT (intensity modulated radiation therapy),a 2D diode array (2D-DA) was used in verifying the composite dose distribution of IMRT plans in the way of multi-gantry-angle composite (MGAC).Methods IMRT quality assure (QA) plans of 27 patients,based on the 2D-DA and solid water phantom,were designed and verified in two ways of single-gantry-angle composite (SGAC) and MGAC verifications.The comparison and analyzation of the dose distributions of the TPS calculation and the measurement of the 2D-DA were done.Results (1) When the beam central axes were not superposed with the detectors'plane of the 2D-DA,the verification passrate of SGAC and MGAC planar dose distribution of 27 patients'IMRT plan were 94.56%±4.28% and 94.81%±3.80% (the criteria:rvalue,3 ram/3%),respectively.There was no statistical difference between the results of two sets (t =-0.213,P＞0.05).(2) When one of the beam central axes was superposed with the detectors'plane of the 2D-DA,the verification passrate of MGAC planar dose distribution were 79.72%±12.77%.Conclusions Using the 2D-DA with a proper phantom,there was no statistical difference in the SGAC and MGAC verifications of IMRT plans when the beam central axes were not superposed with the detectors'plane.However,the MGAC dose distribution can provide more about the clinical dosimetry,and the errors in the implementation of the of IMRT were easier located.