title: Optimized target localization in stereotactic radiosurgery using real-time digital portal images.
abstract: This paper presents a method for optimized estimation of target localization in stereotactic radiosurgery using real-time digital portal images. The positions of the two radiation sources and the two projection planes in radiosurgery can be chosen arbitrarily. The reconstruction of the target is characterized as a non-linear multi-variable optimization problem, which minimizes the difference between the actual target and the reconstructed target. This optimization problem is solved by the Gaussian least square differential correction (GLSDC) method. Due to the digitized errors and input data errors, the algorithm defines an indirect reference factor (the shortest distance between two x-rays pointing onto the target) as an indication of the accuracy of the method. Our experimental results show that the reference factor is less than 1.0 mm for the correct data entry. The proposed algorithm provides a method that supports on-line target localization which can be done directly on the digital portal imaging device.
authors.affiliation: Department of Radiation Medicine, Roswell Park Cancer Institute, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Young
mesh_terms: D000465:Algorithms; D006801:Humans; D016011:Normal Distribution; D019047:Phantoms, Imaging; D011859:Radiography / Q000379:methods*; D016634:Radiosurgery / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results