title: The IMRT information process-mastering the degrees of freedom in external beam therapy.
abstract: The techniques and procedures for intensity-modulated radiation therapy (IMRT) are reviewed in the context of the information process central to treatment planning and delivery of IMRT. A presentation is given of the evolution of the information based radiotherapy workflow and dose delivery techniques, as well as the volume and planning concepts for relating the dose information to image based patient representations. The formulation of the dose shaping process as an optimization problem is described. The different steps in the calculation flow for determination of machine parameters for dose delivery are described starting from the formulation of optimization objectives over dose calculation to optimization procedures. Finally, the main elements of the quality assurance procedure necessary for implementing IMRT clinically are reviewed.
authors.affiliation: Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Akademiska Sjukhuset, SE-751 85 Uppsala, Sweden. anders.ahnesjo@onkologi@uu.se
authors.forename: Anders
authors.initials: A
authors.lastname: Ahnesjö
authors.forename: Björn
authors.initials: B
authors.lastname: Hårdemark
authors.forename: Ulf
authors.initials: U
authors.lastname: Isacsson
authors.forename: Anders
authors.initials: A
authors.lastname: Montelius
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004867:Equipment Design; D005544:Forecasting; D006801:Humans; D008954:Models, Biological; D009369:Neoplasms / Q000532:radiotherapy*; D011874:Radiometry / Q000379:methods* / Q000639:trends; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods* / Q000639:trends; D020266:Radiotherapy, Conformal / Q000379:methods* / Q000639:trends