Atypical teratoid/rhabdoid tumors (AT/RT) are a group of rare highly aggressive malignant tumors in young patients. Among all the malignant tumors of the central nervous system (CNS) in children, they are 1–2 %, which, due to the small number of groups, makes it difficult to develop uniform recommendations for antitumor therapy. The molecular genetic profile of AT/RT, which largely determines the characteristics of the disease, has been studied sufficiently. Despite the large number of ongoing clinical studies, the results of treatment of AT/RT CNS in the world today remain unsatisfactory. The early age of patients limits the use of radiation therapy, which leads to the need to intensify chemotherapy regimens and to choose the optimal strategy in the toxicity – benefit ratio. The article describes modern approaches to the treatment of central nervous system disorders in children, presents the results of studies with the largest number of included patients, using the multimodal treatment strategy, identifies current trends in targeted therapy.Conflict of interest. The authors declare no conflict of interest.Funding. The study was performed without external funding.

Methotrexate (MTX) is a widely used anti-tumor drug, folic acid antagonists. The effectiveness of high doses (more than 1 g/m2) of MTX in a monotherapy or in a combination with other chemotherapeutic drugs has been proven in a treatment of a large spectrum of oncological diseases in children such as osteosarcoma, tumors of the central nervous system, lymphomas, acute lymphoblastic leukemia. The use of high doses of MTX is often fraughted with development of life-threatening complications such as MTX-induced acute kidney injury, neurotoxicity, myelosuppression. Currently developed recommendations for therapeutic monitoring and supportive care, including hyper-hydration, urine alkalization and leucovorin therapy, allow to reduce toxicity of MTX, but in some patients it is not always possible to prevent the development of complications. Cohort studies in order to identify risk factors for toxicity after high doses of MTX in children with different forms of cancer are limited, as well as comparing various types of supportive care regimens, including, infusion therapy. Studying of development mechanisms of MTX toxicity depending on background conditions will allow to improve existing recommendations and develop new and most effective standards of supportive therapy with respect to the individual specifics of patients.