The advancement of technology in the field of radiation therapy now allows us to use precision and clinically high-quality radiotherapy techniques for oncological patient treatment to restrict irradiation of normal tissues and increase tumor control in the surrounding area. The rigorous adherence to the requirements for the precision of the dose supplied is a necessary condition for the application of the justification principle. The enhancement and careful adherence to the nice assurance (QA) application in the radiological department ensures high standards of radiation treatment.