DEVELOPMENT AND APPROBATION OF THE METHOD OF ADAPTIVE RADIOSURGERY IN PATIENTS WITH METASTATIC BRAIN LESION

Background. Intracranial metastases are detected in more than 20% of patients with advanced cancer; they dramatically worsen the prognosis for life and are one of the most common causes of death. Surgical resection and whole brain radiotherapy have been considered the standard treatments for cerebral metastases for many decades. Stereotactic radiosurgery (SRS) is increasingly used in the treatment of intracranial metastases. However, the treatment of large metastases by single-fraction SRS is problematic, since the administration of a dose that provides a sufficient level of local control is associated with a high risk of severe post-radiation complications. Purpose. To develop modes of fractionation for the use of SRS in irresectable patients with metastatic brain lesions and approbate the method of adaptive stereotactic radiosurgery (ASRS). Material and methods. The study included 39 patients with metastatic brain lesions, who in 2018-2021 underwent a two-fraction or three-fraction ASRS according to the developed method using the gamma-therapeutic complex "Gamma Knife Perfexion" (Elekta, Sweden). The average volume of metastases at the time of the first session was 11.9 cm3. Results. The median overall survival in the general cohort was 13.0 months, 1-year survival rate was 75.0%. When assessing local control, the absence of progression 6 months after irradiation was found in 33 out of 39 patients (84.6%). Conclusions. Analysis of literature data and our own preliminary experience demonstrate the relevance of the development and implementation of the ASRS method in the treatment of irresectable patients with metastatic brain lesions.