Evaluation of Beam Profiles between Physical and Enhanced Dynamic Wedges

Abstract

Background: The purpose of the work is to find out the beam profiles using physical and enhanced wedges of different angles, different field sizes, and different energies and to compare them. Materials and Methods: The study was conducted using the Varian Clinac iX LINAC with different photon energies—6 MV and 15 MV. The slab phantom is arranged at a fixed depth (10 cm depth) above the IBA MatriXX device, which consists of 1020 vented ion chamber 2D array detectors arranged in a 32 × 32 grid. The physical and enhanced dynamic wedges at different angles (15°, 30°, 45°, and 60°) were examined for the field sizes 5x5 cm², 10x10 cm², 10x115×15 cm² by delivering 50 monitoring units (MU). Result: In comparison of beam profiles (without rescaling) of PW and DW obtained from 2D array measurement, it was found that there was a difference, but the gradient of curves is almost the same except for some points in the toe, heel, and penumbral region, which is negligible. From the beam profiles, it was understood that a. The difference between PW and DW increased with the increase of wedge angle while field size and energy were fixed. b. The difference between PW and DW increased with increasing field sizes while energy and wedge angle were fixed. c. The difference between PW and DW increased with increasing energy while field size and wedge angle were fixed. Conclusion: Based on the results of our study, it can be concluded that the Universal detector 2D array (matrix) can be used effectively to obtain the dosimetric characteristics of both EDW and physical wedges.

Bangladesh J. Nuclear Med. 28(2): 270-274, July 2025