The Relationship between the Number of Segments and Gantry Angle on the Complexity of Head and Neck IMRT Plans

Purpose: This study aims to investigate the relationship between the Modulation Complexity Score (MCS) and the number of Monitor Units (MUs), number of segments, and gantry angles. Materials and Methods: Treatment planning was performed for 60 patients with head and neck tumors using the step-and-shoot IMRT technique on the RayStation Treatment Planning System (TPS). Treatment plans were divided into two groups, including 30 simple plans (group 1) and 30 complex plans (group 2). Then the relationship between the MCS and the number of Monitor Units (MUs), the number of segments, and the MCS per beam for different gantry angles in the two groups and all plans was investigated. Results: The Pearson correlation results for both groups and all plans showed a strong relationship between the number of MUs and the MCS (p