title: Examination of the effect of increasing the number of radiation beams on a radiation treatment plan.
abstract: Within the confines of least-squares operations, it is possible to quantify the effect of the addition of treatment fields or beamlets to a treatment plan. Using linear algebra and eigenvalue perturbation theory, the effect of the increase in number of treatments is shown to be equivalent to adding a perturbation operator. The effect of adding additional fields will be negligible if the perturbation operator is small. The correspondence of this approach to an earlier work in beam-orientation optimization is also demonstrated. Results are presented for prostate, spinal and head and neck cases, and the connection to beam-orientation optimization is examined.
authors.affiliation: Stanford University Medical Center, Stanford, CA 94305-5304, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Crooks
authors.forename: Andrei
authors.initials: A
authors.lastname: Pugachev
authors.forename: Christopher
authors.initials: C
authors.lastname: King
authors.forename: Lei
authors.initials: L
authors.lastname: Xing
mesh_terms: D004307:Dose-Response Relationship, Radiation; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006801:Humans; D008297:Male; D015233:Models, Statistical; D008962:Models, Theoretical; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011878:Radiotherapy / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*