Evaluation on repeatability of the aperture sizes of CyberKnife VSITM Iris collimator / 中华放射医学与防护杂志

ABSTRACT

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.