Using EGS4 Monte Carlo in medical radiation physics.

Monte Carlo modelling of particle transport problems in medical radiation physics offers significant advantages over other techniques. Experiments can be performed without having to set up the physical situation, and "impossible" experiments can be performed, such as labelling multiple-scattered particles or simulating the effect of chamber walls on dosimetry. The availability of standardised Monte Carlo packages (EGS4 and ETRAN/ITS), along with the development of more powerful and inexpensive computers has allowed more widespread use of the technique. This report discusses the principles of Monte Carlo modelling in general, then examines the EGS4 Monte Carlo package in more detail, with particular reference to its use in medical physics applications.