Conversion of leaf sequences to dose distributions in micro-IMRT

Calculation of accurate dose to the patient is an essential aspect of IMRT planning. This step can be particularly difficult when fields are small as is often the case when a micro MLC is used. Convolving a Gaussian source, head scatter function and pencil beam kernel with the `opening density´ map, with the addition of leakage, is shown to give a good match to dose at dmax measured with film for the case presented here. The use of ImFast to calculate the fluence (taking into account the actual leaf positions) and subsequently convolving this with only the pencil beam kernel also gives a good match and is in principle more rigorous