The Research On The Application Of Image Registration In The Error Analysis Of Ct Simulation

Objective:To analysis the error between the geometric center of the three-dimensional conformal radiotherapy and the center proofread by the CT simulation machine.verify the error range and improve the precision of radiotherapy by using image registration. Methods:30 cases who need chest radiotherapy,have already been fixed, received the scan by Phlipis 16 rows large aperture CT simulation machine for exclusive use of radiotherapy.Input the scanned image to three-dimensional treatment planning system Eclipse7.0 and devise the radiotherapy plan,proofread the center by the CT simulation machine and mark on the body cover after the plan finished with the geometric center being fixed on,scan image according to the proofread center and input it to three-dimensional treatment planning system Eclipse7.0. and then deal with the image by using image registration. Find out and analysis the error of the two centers in the three-dimensional direction after comparing the location of the two images center. Results:The accuracy in X.Y,Z direction is 2.20 mm,2.34 mm and 3.21 mm respectively, the precision in X,Y,Z direction is 1.20 mm.1.37 mm and 1.74 mm respectively, with the total accuracy and precision 4.99 mm and 1.34 mm respectively. While the mean error in X,Y,Z direction is 2.20±1.20 mm,2.30±1.95 mm and 3.50±3.48 mm respectively. There were statistical differences in the mean error of the three direction (χ2=6.773,P=0.034). Conclusions: The error between the geometric center of the three-dimensional conformal radiotherapy and the center proofread by the CT simulation machine compared by using image registration is in the acceptable range (they are smaller than 5 mm in three-dimensional direction),and it is feasible to make the error analysis by using image registration.