Evaluation of Dosimetric and Radiobiological Parameters for Different TPS Dose Calculation Algorithms and Plans for Lung Cancer Radiotherapy

Abstract

Lung cancer presents a major public health concern in our country and around the globe. Radiotherapy is one of the main treatment modalities for lung cancer management for several years. This study aims to evaluate differences in the dosimetric and radiobiological parameters and in the dose distributions of Planning Target Volume (PTV) and organs at risk (OAR) in patients with lung tumors using different Treatment Planning System (TPS) algorithms and Volumetric Modulated Arc Therapy (VMAT) technique. This study was accomplished in a group of 19 patients with lung tumors who were treated in our clinic. In the treatment planning of the patients; Elekta-Monaco with Monte Carlo (XVMC), Pencil Beam algorithm; Varian-Eclipse with Anisotropic Analytical Algorithm (AAA), Acuros XB (AXB)algorithms and Tomo-plan Treatment Planning System with Convolution Superposition algorithm of Tomotherapy device were used. In these treatment planning systems, plans were done by 6 MV photon energy using Volumetric Arc Therapy (VMAT) techniques. The prescribed dose to the PTV was 60 Gy in 30 fractions. Statistical analysis was performed using SPSS Statistics v.29.0.2.0 programme. Statistically, significant differences were found in Dmean, Dmax, D2 and D98 values for PTV between the algorithms, while small differences were found in Dmax values of the contralateral lung, total lung and esophagus in critical organs. It is concluded that the difference between algorithms for PTV increases especially as the volume of the target tumor decreases. TPS with C/S algorithm gave closer results with XVMC. Algorithms were found to have an impact on radiobiological parameters.