The article describes the stages of development of the Radiation Therapy Department at the N.N. Petrov NMRC of Oncology from its establishment in the premises of the hospital named after I.I. Mechnikov to the current state of the department. The contribution of the staff to the development of the scientific and clinical activities of the institution, the training of qualified professionals and scientific personnel and the relationship of this process with other medical and educational institutions in our country were highlighted. The article is dedicated to Professor Anatoly G. Vesnin, head of Radiation Therapy Department at the Research Institute from 1982 to 2007. The man under whose leadership the department has been transformed. He saw it through the collapse of the Soviet Union, the difficult 1990s and the subsequent recovery.