title: IMRT sequencing for a six-bank multi-leaf system.
abstract: In this study, we present a sequencer for delivering step-and-shoot IMRT using a six-bank multi-leaf system. Such a system was proposed earlier and combines a high-resolution field-shaping ability with a large field size. It consists of three layers of two opposing leaf banks with 1 cm leaves. The layers are rotated relative to each other at 60 degrees . A low-resolution mode of sequencing is achieved by using one layer of leaves as primary MLC, while the other two are used to improve back-up collimation. For high-resolution sequencing, an algorithm is presented that creates segments shaped by all six banks. Compared to a hypothetical mini-MLC with 0.4 cm leaves, a similar performance can be achieved, but a trade-off has to be made between accuracy and the number of segments.
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. R.Topolnjak@azu.nl
authors.forename: R
authors.initials: R
authors.lastname: Topolnjak
authors.forename: U A
authors.initials: UA
authors.lastname: van der Heide
authors.forename: J J W
authors.initials: JJ
authors.lastname: Lagendijk
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D019583:Dose Fractionation, Radiation; D019544:Equipment Failure Analysis / Q000379:methods*; D006801:Humans; D008954:Models, Biological; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000295:instrumentation* / Q000379:methods*; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity