Abstract
Relevance: Dosimetric planning in radiotherapy for patients with head and neck tumors, as well as pelvic tumors, is complicated by anatomical complexity and the proximity of critical organs to the target volume. This necessitates the use of modern optimization methods to improve the quality of treatment plans. This study aimed to compare volumetric modulated arc therapy treatment plans with and without multi-criteria optimization in patients with head and neck and pelvic tumors, evaluating target coverage and radiation dose to organs at risk. Methods: The study included 34 patients, including 17 with head and neck tumors and 17 with pelvic tumors. For each case, two treatment plans were generated: one with MCO and one without. Planning was performed in the Eclipse system (Varian Medical Systems, USA). Comparative analysis was conducted based on target coverage indices (Planning Target Volume, PTV) (D95%, D2%) and dose load to organs at risk (Organs at Risk, OARs). Results: The use of MCO provided more homogeneous and complete PTV coverage while simultaneously reducing radiation dose to critical structures. The most pronounced effect was observed in head and neck tumor cases, where the anatomical proximity of OARs complicates standard planning. Conclusion: MCO is an effective tool for improving dosimetric planning quality, especially in cases with high anatomical complexity, and can be recommended for clinical practice in radiotherapy planning.