10.18453/rosdok_id00005902 Kalinowski, Thomas Thomas Kalinowski http://d-nb.info/gnd/128420251 https://orcid.org/0000-0002-8444-6848 University of Rostock, Institute of Mathematics 2004 510 Mathematics 2004 en https://purl.uni-rostock.de/rosdok/id00005902 urn:nbn:de:gbv:28-rosdok_id00005902-1 Multileaf collimators (MLCs) are the prevailing tool for the realization of radiation fields in intensity modulated radiation therapy (IMRT). One step in the treatment planning is to determine a set of leaf positions realizing a certain intensity modulated radiation field. In this paper we suggest two extensions in the use of the MLC that lead to considerable savings in terms of monitor units, thus potentially increasing the treatment quality. We test our method with random and with clinical sample matrices.