Course book Advanced Treatment Planning 2018

Effect of collimator angle depends on the IMRT delivery

▪ In step&shoot delivery: block the ‘central area’

segment 1

segment x

▪ in d-MLC delivery: leafs should be closed when travelling ‘across’ the central area Elekta MLCi 90º versus Varian / Elekta MLCi2: 0º / 90º or allow for ‘ move only segments ’