title: A novel method to correct for pitch and yaw patient setup errors in helical tomotherapy.
abstract: An accurate means of determining and correcting for daily patient setup errors is important to the cancer outcome in radiotherapy. While many tools have been developed to detect setup errors, difficulty may arise in accurately adjusting the patient to account for the rotational error components. A novel, automated method to correct for rotational patient setup errors in helical tomotherapy is proposed for a treatment couch that is restricted to motion along translational axes. In tomotherapy, only a narrow superior/inferior section of the target receives a dose at any instant, thus rotations in the sagittal and coronal planes may be approximately corrected for by very slow continuous couch motion in a direction perpendicular to the scanning direction. Results from proof-of-principle tests indicate that the method improves the accuracy of treatment delivery, especially for long and narrow targets. Rotational corrections about an axis perpendicular to the transverse plane continue to be implemented easily in tomotherapy by adjustment of the initial gantry angle.
authors: Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53706, USA. saboswell@wisc.edu
authors: Sarah A
authors: SA
authors: Boswell
authors: Robert
authors: R
authors: Jeraj
authors: Kenneth J
authors: KJ
authors: Ruchala
authors: Gustavo H
authors: GH
authors: Olivera
authors: Hazim A
authors: HA
authors: Jaradat
authors: Joshua A
authors: JA
authors: James
authors: Alonso
authors: A
authors: Gutierrez
authors: Dave
authors: D
authors: Pearson
authors: Gary
authors: G
authors: Frank
authors: T Rock
authors: TR
authors: Mackie
mesh_terms: D004867:Equipment Design / Q000379:methods; D006257:Head / Q000528:radiation effects; D006801:Humans; D015233:Models, Statistical; D008962:Models, Theoretical; D009068:Movement; D010315:Particle Accelerators; D019047:Phantoms, Imaging; D011874:Radiometry / Q000379:methods; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted; D020266:Radiotherapy, Conformal / Q000379:methods*; D011882:Radiotherapy, High-Energy; D015203:Reproducibility of Results