Overall survival of children with brain tumors after radiation therapy in Kazakhstan.

Abstract

e22011 Background: Tumors of the central nervous system in children occupy the 2nd place in frequency in the structure of malignant neoplasms of childhood and the 1st place among solid tumors. They make up about 20% of all malignant neoplasms of childhood and are mainly represented by brain tumors. The purpose of the study was to analyze the survival rate depending on various factors during radiation therapy (RT) of brain tumors in children. Methods: Retrospective study included 277 patients who received RT from 2016 to 2020 at the Pediatric Oncology Center of the Kazakh Research Institute of Oncology and Radiology. The average follow-up time was 34.3 months. The median age was 9.5 years. RT was performed on a linear accelerator “TrueBeam”, in a single dose of 1.8 Gy, total 50.4-54.0 Gy, 5 fractions per week. Survival distributions was estimated by Kaplan and Meier curves and survival differences were evaluated using the log-rank test. IBM SPSS Statistics V23 was used for statistical analyses. Results: The overall survival (OS) rate of 277 patients was 70.8%, with an average life time of 55.6 months, 95% confidence interval (CI) (51.9 - 59.2). Children under 10 years of age showed a 12.5 % worse OS compare to children after 10 years of age. In patients with unconfirmed morphological verification, OS is 31.5% worse than in children with confirmed morphological verification. In children with grade I-II tumor differentiation, OS was 30.6% higher than in children with grade III-IV tumors. The method of RT (conformal RT, IMLT), gender of patients did not have a statistically significant effect on OS. Conclusions: Our study showed that OS rate depends on various factors, such as age, presence of morphology verification, and the degree of tumor differentiation. RT allows to achieve better survival in patients older than 10 years who received RT with a morphologically confirmed diagnosis of GI-II. RT is one of the main treatments for brain tumors in children.[Table: see text]