Assessment of image co-registration accuracy for frameless gamma knife surgery
Fig 3
The procedure used to examine the accuracy of stereotactic coordinate assignment.
A fiducial marker-based system was defined using the fiducial markers in the stereotactic CT images. A co-registration-based system was assigned by co-registering the stereotactic CT images with reference CBCT images. A CBCT-based system was intrinsically defined so that its center was calibrated to the radiation focus. The coordinates of the landmarks measured in each coordinate system were compared.