Modern aspects of diagnosis and treatment of ependymomas in children

Ependymomas (E) are a group of tumors that arise from the ependymal lining of the ventricular system of the brain or the central channel of the spinal cord. They make up 8 - 10% of all central nervous system (CNS) tumors in children, ranking 3rd after embryonic tumors and astrocytes of various degrees of differentiation. The approximate frequency of occurrence per 1 million children aged 0 to 15 years is 4 cases. The peak incidence occurs in the age group of up to 10 years. The clinical picture of E mainly depends on the location of the tumor. The main method of preoperative diagnosis is currently magnetic resonance imaging, and the leading method of treatment is surgical removal with the addition of radiation and chemotherapy. Currently, a number of clinical prognostic factors have been established in the treatment of E: the volume of surgical intervention, the degree of malignancy of the tumor, postoperative adjuvant therapy, and the patient's age. Research has been initiated on the molecular features of E, which in the future may take a leading place in predicting the course of the process and individualizing treatmentprograms. The main cause of failures in the treatment of E remains the recurrence and metastasis of the tumor, the frequency of which, according to various data, reaches 25 - 50%. Along with the success achieved in the treatment of E, a number of problems remain unresolved. The solution of these problems could contribute to improving the effectiveness of treatment of children with E. Among these problems, we can mention the following ones: local increase of the radiation dose in the presence of a residual tumor beyond the accepted limit of 54 - 59 Gy, expansion of the radiation volume to the entire cranio-spinal space in the case of tumor recurrence and in the presence of tumor cells in the liquor at the time of primary treatment, selection of optimal modes and total doses of repeated radiation therapy, prevention of radiation damage to healthy brain structures, assessment of the true effectiveness of adjuvant chemotherapy, the role of molecular genetic features of the tumor in the prognosis of the disease. In this review, we analyzed the available information about the current state of the problem of diagnosis and treatment of E and possible directions of further progress in the state of care for this category of children.