Monte Carlo study of in‐field and out‐of‐field dose distributions from a linear accelerator operating with and without a flattening‐filter

Abstract

The build-up and depth-dose characteristics of a conventional "6 MV" beam can be maintained when changing to a flattening-filter-free modality by increasing the incident electron energy from 6.45 MeV to 8.0 MeV. This will at the same time reduce the out-of-field dose for regions up to 20 cm from the central axis by 10%-30% compared to the original FF situation.