Comparison of Different Algorithms in the Radiotherapy Plans of Breast Cancer

¹ Department of Radiation Oncology, University of Kocatepe, 03200, Afyon, Turkey
² Department of Materials Science and Engineering, University of Kocatepe, 03200, Afyon, Turkey

^* Corresponding author: yoncayashsi@gmail.com

Abstract

It is aimed to evaluate portal dosimetry results of planned breast cancer patients with intensity-modulated radiotherapy (YART) of Anisotropic Analytical Algorithm (AAA) and Pencil Beam Convolution (PBC) dose calculation algorithms. The plans of 10 treated patients will receive 6 MV photon energy and a total of 25 fractions of 50 Gray dose using the inverse YART technique, which is reverse planned in the Eclipse (ver.13.6) treatment planning system with Varian Trilogy Linear Accelerator prescribing. For each plan, dose was calculated after optimization using PBC and then AAA algorithms. The quality controls of the plans were made using the Electronic Portal Imaging Device (EPID) by creating individual verification plans for each algorithm. In addition, the maximum and average dose values in the target volume were compared in inverse YART plans calculated using PBC and AAA. When treatment plans generated by AAA and PBC dose calculation algorithms are analyzed using EPID, for the PBC algorithm, the mean values of V_Area and V_Avg are 98.15 ± 1.07, 0.40 ± 0.048 and 98.72 ± 1.13, 0.37 ± 0.051, respectively, for the AAA algorithm. The PTV D_max value for the PBC algorithm is 109.3 ± 1.09 and the D_Avg value is 101.7 ± 0.51. For the AAA algorithm, the PTV D_max value is 110.6 ± 1.12 and the D_Avg value is 102.9 ± 0.62. When the mean values of portal dosimetry V_Area and V_Avg evaluated using PBC and AAA algorithms were compared, the differences between the algorithms were not statistically significant (p> 0.05). Differences between the algorithms for PTV D_max and D_Avg values are not statistically significant (p> 0.05).