Slide 1

Effect of collimator angle depends on the IMRT delivery



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



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

’

segment 1

segment x