The importance of medical physics methods in modern radiation therapy is shown. The types of irradiation used in radiation therapy are considered. At each stage, it is necessary to maintain high accuracy of all procedures. One of the significant stages is the treatment planning, where the quality control of the plan is carried out to ensure the accuracy of the treatment of the patient. The process of quality control of radiation plans in radiation therapy with intensity modulation (Volumetric Modulated Arc Therapy - VMAT) on the VitalBeam linear accelerator is presented. The widely used method of quality control on the portal detector (Electronic Portal Imaging Device, EPID) of the radiation therapy plan with intensity modulation (Volumetric Modulated Arc Therapy - VMAT) is considered. Comparison of dose distribution that is the overlapping of dose distribution contours. Isodose lines and a dose-volume histogram for a plan with intensity modulation are presented and the main dimensional geometries used in clinical practice for dosimetric examination of treatment plans are described. Intensity modulated plan gamma analysis (VMAT) and gamma analysis criteria are defined. As well as the coverage of the physical volume of exposure. Quality control of dosimetric distributions of the intensity modulated treatment plan (VMAT) on the VitalBeam linear accelerator was assessed.