Background & objective: Localization error in X-ray radiosurgery for tumors in eyeball was common due to the rotation of eyeball. The accuracy and precision of X-ray radiosurgery was studied by fixing the eyeball with micro-vacuo-certo-contacting ophthalmophanto (MVCCOP) to reduce the error in this article.
Methods: CT localization accuracy of X-ray radiosurgery system was measured using special markers in skull phantom. The eyeballs were fixed using MVCCOP, which was designed by the authors, and then the eyeball fixation accuracy and target localization accuracy were measured by comparing the CT localization coordinates and verification coordinates of corresponding points.
Results: The mean error of CT localization of BRW head-ring was 0.65 mm and maximum error was 1.09 mm. The mean error of fixation of eyeball using MVCCOP was 0.84 mm and maximal error was 1.17 mm. The accuracy of tumor localization in eyeball was 0.87 mm averagely and 1.19 mm maximally. The mean error of SRS200 was 0.22 mm and maximum error was 0.32 mm. The total error was 1.40 mm and 95 percentile confidence error was 2.12 mm.
Conclusion: The accuracy and precision of X-ray radiosurgery using MVCCOP has come up to the standard of quality control of stereotactic radiosurgery. This localization method can reduce the localization errors in radiosurgery caused by the rotation of eyeball.