Correlation Between CT-Simulator and Dynamic Magnetic Resonance Images in Determining The Location of Gross Tumor Volume in Radiotherapy Treatment Planning for Lung Cancer

Abstract

Objective: This study aimed to determine the accuracy of the average tumor location in CT-simulator images and PTV margins in radiotherapytreatment planning by detecting lung tumor mobility in dynamic MRI scans of patients presenting with lung cancer.Materials and Method: Dynamic MRI examination was performed in 12 lung cancer patients scheduled for 3-dimensional conformal RT(3D-CRT) using CT-simulator. In this study, maximum tumor displacement (CC-MRI, ML-MRI, AP-MRI) was measured that occurred in CC,AP and ML axes in expiratory and inspiratory phases of dynamic MRI. The distance from the upper limit of GTV to the reference line (CC-CT)was measured in CT-simulator images. CC-CT and CCmean-MRI values were compared with the Wilcoxon signed-rank test. Furthermore,correlation of these values was evaluated with Spearman’s correlation test.Results: In comparison of CC-CT and CCmean-MRI values, no statistically significant difference was detected between CT-simulator anddynamic MRI modalities (p=0.172). In addition, a high level of correlation was found between these two imaging methods (p