comparison of mcnp4c, 4b and 4a monte carlo codes when calculating electron therapy depth doses

abstract background: accurate methods of radiation therapy dose calculation. there are different monte carlo codesfor simulation of photons, electrons and the coupled transport of electrons and photons. mcnpis a general purpose monte carlo code that can be used for electron, photon and coupledphoton-electron transport.monte carlo simulation of radiation transport is considered to be one of the mostmaterials and methods: calculating electron beam doses in water. for simulating, the geometry and other parameterswere the same for three codes. by choosing two energy indexing algorithm (its & mcnp),absorbed doses were scored in water. 10in this study the mcnp4a, 4b and 4c have been compared when6 particles were followed in these three cases.results: used in 4b and 4c versions. there was a good agreement between versions 4b and 4c. for theenergy spectrum, there were significant differences between these three versions in two planes.mcnp4c and 4b gave different results compared to 4a when the its algorithm wasconclusion: for electron transport and also requires a shorter time than the two previous versions. theseresults, in addition to the practical measurements acquired with mcnp4b by other investigators,suggest that in electron transport the user should use the its indexing energyalgorithm. because of new improvements in electron transport in 4c, this version is reliableiran. j. radiat. res., 2005 2 (4): 191-195keywords: radiotherapy, electron therapy, monte carlo, absorbed dose, energy spe