Linac Stereotactic Cone Alignment

Description

To align the patient setup lasers in a radiation therapy treatment toom with the radiation field isocenter, an 8 mm ball-bearing (BB) phantom was placed at the intersection of the room laser. Portal images were taken at recommended gantry, collimator and couch angles. The RIT software automatically calculates the systemic displacement on each principal axis using the method described in Low's paper on minimization of target localization error in accelerator based radiosurgery. The 3D dispalcement is the simple Euclidean vector magnitude of the three axes arrors.

Virtual Starshots of the Gantry, Couch and Collimator are generated and displayed individually. Lasers of each of the axis can be adjusted according to reported variations.