Leksell Icon型伽玛刀锥形束CT的常规质量控制与评价

目的分析Leksell Icon型伽玛刀锥形束CT的常规质量控制结果,评估其长期稳定性。方法使用QA TOOL plus验证锥形束CT精度;扫描Catphan 503模体,分析图像空间分辨率、对比度-噪声比和均匀性。结果锥形束CT图像体积的最大偏差为0.09~0.17 mm,均通过精度测试;预设的CT剂量指数2.5和6.3 mGy扫描模式下,空间分辨率很稳定,分别为7和8 lp/cm;对比度-噪声比和均匀性均符合参考要求。结论12个月的Leksell Icon型伽玛刀锥形束CT的常规质量控制比较稳定。锥形束CT的质量控制除了参考厂商的调试基线值外,针对伽玛刀统一的分析评价标准有待进一步完善。

Conventional quality control and evaluation of Leksell Icon Gamma Knife cone-beam CT

Objective To analyze the conventional quality control result of Leksell Icon Gamma Knife cone-beam CT and evaluate long-term stability of cone-bem CT.Methods QA TOOL Plus was used to verify the accuracy of cone-beam CT. The phantom Catphan 503 was scanned, and the image spatial resolution, contrast to noise ratio and homogeneity were analyzed.Results The maximum deviation in image volume of cone-beam CT was 0.09-0.17mm, which passed the accuracy test. At the scanning patterns with CT dose index of 2.5 and 6.3mGy, the spatial resolution was very stable at 7 and 8 lp/cm respectively. The contrast noise ratio and uniformity meet the reference requirements.Conclusions The conventional quality control results of Leksell Icon Gamma Knife cone-beam CT are stable in 12 months. In addition to referring to the manufacturer''s baseline value, the unified analysis and evaluation standard for Gamma Knife need to be further improved for the quality control of cone-beam CT.