Volume difference between Internal Target Volume (ITV) and Deformable Image Registration (DIR_ITV): A comparative analysis.

This study investigates the essential role of Radiation Therapy Quality Assurance (RTQA) procedures in modern radiotherapy treatments, particularly focusing on Stereotactic Body Radiation Therapy (SBRT) for centrally located lung malignancies. This study aims to compare the effectiveness of three commonly used metrics DSC (Dice Similarity Coefficient), GMI (Geometric Miss Index), and DI (Discordance Index) in assessing patients with specify condition/population. We focus on three key aspects: the Initial Tumor Volume (ITV) as delineated at 0 of the prescribed dose (ITV_0% P_DIR), 50% of the prescribed dose (ITV_50% P_DIR), and Maximum Intensity Projection (ITV_MIP). The analysis reveals significant differences among the metrics in evaluating tumor characteristics at different dose levels and imaging perspectives. Notably, DSC provided distinct insights into tumor perfusion dynamics, particularly evident in the delineation of ITV_0 P_DIR and ITV_50% P_DIR. GMI exhibited strengths in capturing subtle variations in tumor morphology, with ITV_0 P_DIR comparisons showing its utility. DI has turned out to be a valuable tool in delineating spatial heterogeneity, with significant findings observed between ITV_50% P_DIR and ITV_MIP. These findings underscore the importance of selecting appropriate metrics tailored to the specific diagnostic or prognostic objectives in patients with specify condition/ population. [ABSTRACT FROM AUTHOR]