The effect of linear accelerator use on primary barrier design

In the planning of radiotherapy treatment rooms and also in the assessment of the effectiveness of shielding in completed rooms, data will be required about the use of the treatment equipment and in particular about the distribution of beam directions that are used. If detailed information is not available, assumptions have to be made. It has been possible to build up a fuller picture of the orientation of the gantry arm and the field sizes used during 8 MV X-ray treatments by using the daily treatment records provided by the Philips Vericord system attached to a Philips SL75-14 linear accelerator.