眼内肿瘤X射线放射外科治疗精确度研究

Accuracy and Precision of X-ray Radiosurgery Treatment for Tumors in Eye ball

背景与目的:眼内肿瘤X射线放射外科治疗受眼球旋转的限制,常规定位方法误差极大。本研究探讨用微真空角膜接触眼球固定器固定眼球进行放射外科治疗的精确度。方法:人体头颅模型内特定标记物测定CT定位的精确度;应用我院研制的微真空角膜接触眼球固定器固定眼球,进行眼内肿瘤CT扫描和验证扫描,测定眼球固定精确度和靶区定位精确度。结果:CT平均定位误差为0.65mm,最大误差为1.09mm。利用微真空角膜接触眼球固定器固定眼球,精确度为0.84mm,最大误差为1.17mm。眼内肿瘤定位精确度为0.87mm,最大误差为1.19mm。SRS200治疗的摆位误差为0.22mm,最大误差为0.32mm。总治疗误差为1.40mm,95%置信概率为2.12mm。结论:利用微真空角膜接触眼球固定器进行眼内肿瘤放射外科治疗精确度高,可减少放射外科治疗时眼球旋转所产生的误差。

BACKGROUND &OBJECTIVE:Localization error in X-ray radiosurg ery for tumors in eyeball w as common due to the rotation of eyeba ll.The accuracy and precision of X-ray r adiosurg ery was studied by fixing th e eyeball with micro-vacuo-certo-co ntacting ophthalmophanto(MVCCOP )to reduce the error in this article.METHODS :CT localization accuracy of X-ray radiosurg ery system was measured us ing special markers in skull phantom.The eyeballs were fixed using MVCCOP,wh ich was desig ned by the authors ,and then the eyeball fixation accuracy a nd targ et localization accuracy wer e measured by comparing the CT localiz ation coordinates and verification coordinates of corresponding point s.RESULTS :The mean error of CT localization of BRW head-ring was 0.65mm and maximum error was 1.09mm.The mean error of fixation of eyeball using MVCCOP was 0.84mm and maximal error was 1.17mm.The accuracy of tum or localization in eyeball was 0.87mm averag ely and 1.19mm maximally.The mean error of SRS200was 0.22mm and maximum error was 0.32mm.The tot al error was 1.40mm and 95percentile confidence error was 2.12mm.CONCLUSION:The accuracy and precision of X-ray radiosurg ery usi ng MVCCOP has come up to the standard o f quality control of stereotactic rad iosurg ery.This localization metho d can reduce the localization errors in radiosur g ery caused by the rotation of eyebal l.