STEREOTACTIC RADIOSURGERY FOR BRAIN METASTASES IN A CHILD WITH EXTRA-SKELETAL EWING'S SARCOMA

Abstract

Ewing's sarcoma is the second most common oncological disease of bones and soft tissues in children and adolescents, which is characterized by rapid growth and early metastasis. Brain metastases (BMs) occur in 10–12 % of cases and constitute a factor in the unfavorable prognosis of the disease. The possibilities of surgical treatment are often limited by the localization of a metastatic tumor, and the vast majority of chemotherapy drugs don’t penetrate the blood-brain barrier, therefore radiation therapy, particularly stereotactic radiosurgery, the principle of which is a single high dose (15–24 Gy) of ionizing radiation to the pathological focus, is the most important method of treatment. High accuracy of tumor irradiation is ensured by rigid immobilization of the patient (using stereotactic frames or individual three-layer thermoplastic masks) in combination with positioning of the patient and control of his position by orthogonal X-rays. According to various authors, the use of stereotactic radiosurgery provides local control over BMs in 90 % of patients, regardless of the histological type of the primary focus, age and gender of the patient. The article describes a clinical case of successful radiosurgical treatment of a child suffering from extra-skeletal Ewing’s sarcoma, in which following the complex treatment, progression of the disease, represented by multiple metastatic brain damage was revealed; the cumulative volume of metastatic foci was 2.3 cm 3 and due to the proximity of the brain stem, as well as in order to avoid exceeding the tolerant load on healthy brain tissues, the total focal dose did not exceed 16 Gy. A complete response to therapy in the form of regression of all foci was noted six months after the treatment. To date, insufficient data has been published on the use of stereotactic radiosurgery in pediatric oncology, but in the available literature, the authors demonstrate the effectiveness and safety of treatment. Further research is needed to study the effect of the radiosurgical method on the children.