AN INVESTIGATION INTO THE COMPARISON BETWEEN DIFFERENT DOSIMETRIC METHODS OF MEASURING PROFILES AND DEPTH DOSES FOR DYNAMIC WEDGES ON A VARIAN 600C LINEAR-ACCELERATOR

Three dosimetric methods for commissioning the dynamic wedges on a Varian 600C linear accelerator operating at 4.7 MV were compared. The techniques involved the use of ionization chambers, x-ray verification film and solid state detectors, lonization chambers gave the most accurate results, as expected, but data acquisition was very time consuming. Film dosimetry was found to have good spatial resolution for beam profiles, but problems were encountered with the acquisition of depth doses. Solid state detectors generally showed reasonable agreement with the ionization chambers.