title: IMRT planning on adaptive volume structures--a decisive reduction in computational complexity.
abstract: The objective of radiotherapy planning is to find a compromise between the contradictive goals of delivering a sufficiently high dose to the target volume while widely sparing critical structures. The search for such a compromise requires the computation of several plans, which mathematically means solving several optimization problems. In the case of intensity modulated radiotherapy (IMRT) these problems are large-scale, hence the accumulated computational expense is very high. The adaptive clustering method presented in this paper overcomes this difficulty. The main idea is to use a preprocessed hierarchy of aggregated dose-volume information as a basis for individually adapted approximations of the original optimization problems. This leads to a decisively reduced computational expense: numerical experiments on several sets of real clinical data typically show computation times decreased by a factor of about 10. In contrast to earlier work in this field, this reduction in computational complexity will not lead to a loss in accuracy: the adaptive clustering method produces the optimum of the original optimization problem.
authors.affiliation: Department of Optimization, Fraunhofer Institut for Industrial Mathematics, Gottlieb-Daimler-Strasse 49, 67663 Kaiserslautern, Germany. scherrer@itwm.fhg.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Scherrer
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Küfer
authors.forename: Thomas
authors.initials: T
authors.lastname: Bortfeld
authors.forename: Michael
authors.initials: M
authors.lastname: Monz
authors.forename: Fernando
authors.initials: F
authors.lastname: Alonso
mesh_terms: D000465:Algorithms; D001822:Body Burden; D003198:Computer Simulation; D003205:Computing Methodologies; D019544:Equipment Failure Analysis / Q000379:methods*; D006801:Humans; D008297:Male; D008954:Models, Biological; D009716:Numerical Analysis, Computer-Assisted; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods*; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity