Comparison between different cancer radiotherapy field shaping techniques using 6 MV and 15 MV photon energies.

Abstract

The aim of this study is to provide technical data bout replacing cerrobend casting blocks by multileaf collimator at the surface dose for different field sides and depths. As part of the commissioning process for a commercially available MLC, percentage depth doses from the surface to a depth of 30 cm have been measured for a number of square fields utilizing 6 MV and 15 MV X-rays. Changes in SSD, the existence of a secondary blocking tray in the beam, and radiation transmission between the MLC leaves were among the variables that were considered. We recommend using multileaf collimator as shaping technique instead of Cerrobend blocks as its economic and less time consuming.