System precision assessment ExacTrac 6D® BrainLab of the Hospital das Clinicas da Faculdade de Medicina da USP

The goal of this study was to evaluate the precision of ExacTrac 6D® Brainlab system, installed at Hospital das Clinicas da Faculdade de Medicina da USP, in frameless radiosurgery treatments. Four sets of tests were performed for different purposes in order to assess the following parameters: the accuracy of location through infrared system; evaluation of the reproducibility of fusion algorithm; evaluation of the X-ray system; and the end-to-end test with the goal of assess the overall accuracy of the system. It was found that the infrared system showed a maximum deviation of 0.5 mm in terms of positioning and the X-ray system showed a precision of 0.15 mm and 0.6°. The reproducibility of fusion algorithms provided a maximum deviation in position which was less than 0.5 mm and 0.5° and the quantitative analysis of the results for end-to-end test showed an overall accuracy of the system better than 0.8 mm. (author)