基于辐射自显影胶片的多叶准直器校准  

Calibration of Multi-leaf Collimator with GAFCHROMIC EBT Film

作　　者：蔡汉飞[1] 沈学明[1] 李贵[2] 

机构地区：[1]蚌埠医学院第一附属医院放射治疗科,安徽蚌埠233004 [2]中国科学院等离子体物理研究所,安徽合肥230031

出　　处：《中国医疗设备》2009年第7期141-144,共4页China Medical Devices

摘　　要：研究一种辐射自显影胶片(GAFCH-ROMIC EBT胶片)用于医用电子直线加速器多叶准直器(MLC)校准的方案设计、实施、数据处理及性能评估。分别使用KODAK X-OmatV胶片和GAFCHROMIC EBT胶片,调用ELEKTA电子直线加速器"MLC Leaf Bank"校准程序,拍片分析计算出MLC校准所需数据,比较两种胶片所得结果。两种胶片报告的叶片绝对位置信息相差约0.1cm,两者在射野宽度的报告上有近0.2cm的偏差。GAFCHROMIC EBT胶片剂量刻度方便准确,报告的叶片位置信息更接近实际位置。文中使用的基于GAFCHROMIC EBT胶片的测量设备测量MLC叶片位置的不确定度小于0.03cm,能满足校准后MLC叶片到位精度在±1mm之内的要求,可用于多叶准直器的常规校准。To evaluate the application of GAFCHROMIC EBT film in calibrating multi-leaf collimator. Procedure recommended by ELEKTA and two types of films （KODAK X-Omat V film and CAFCHROMIC EBT film） were used to collect the information for calibrating ELEKTA Precise MLC, and results measured by these two types of films were compared. Deviation of leaf position determined by KODAK X-Omat V film and GAFCHROMIC EBT film was about 0.1cm, thus made the deviation of field width to be 0.2cm. As dose calibration could be carried out accurately and conveniently, leaf position determined by GAFCHROMIC EBT film was very close to the reality. Equipment based on GAFCHROMIC EBT film used in this paper had an uncertainty less than 0.03cm in determining leaf position, so it could meet the need of MLC calibration, in which the tolerance of leaf position was about ± 1mm.

关 键 词：多叶准直器 质量保证 GAFCH-ROMIC EBT胶片 

分 类 号：R318.6[医药卫生—生物医学工程]