射波刀Iris可变准直器孔径大小的重复性评价

摘要

目的 开展射波刀 Iris可变准直器的研究工作,评价射束大小的可重复性.方法 在射波刀等中心800 mm处辐照胶片,扫描曝光后的胶片并使用Iris质量保证(QA)软件获取胶片上的射束信息.结果 Iris可变准直器在5～40 mm大小范围内标准偏差＜0.11 mm,在50、60 mm的情况下标准偏差＜0.19 mm.结论 射波刀Iris可变准直器孔径大小重复性良好.%Objective To evaluate the repeatability of the aperture sizes based on the Iris variable aperture collimator (Iris collimator) of CvberKnife VSITM.Methods Radiochromic films were placed at 800 mm of source-to-axis distance (SAD),and Iris quality assurance (QA) software was used to extract the information from the digital images,which were exposured by X-ray beams.Results The average aperture accuracy of Iris collimator was better than 0.11 mm over the beam range 5-40 mm,and the accuracy for 50 mm and 60 mm beams was within 0.19 mm.Conclusions The results suggest a good repeatability of aperture sizes for the CyberKnife VSITM Iris collimator.