mielograAnalysis of the results and late side effects postoperative radiotherapy in children with intracranial ependymoma
Abstract
Purpose. This study was conducted to analyze the efficacy of radiotherapy within the combined treatment of children with intracranial ependymoma and also to determine prognostic factors, patterns of failure and late effects after therapy.
Methods and materials. Between 1984 and 2005, 115 children with intracranial ependymoma received radiotherapy after surgery in the Department of Radiation Oncology of the Cancer Center and Institute of Oncology. During this time the radiotherapy protocol was changed. Most patients were treated with craniospinal radiotherapy followed by a boost to the primary site. The remaining patients were treated with conformal local radiotherapy. A new chemotherapy regime was used after 1997. The Kaplan-Meier method was used to estimate survival. Multivariate analysis was performed with the Cox proportional hazards model to study prognostic factors. The risk of occurrence of complications including impairment of intellectual functions, growth, endocrine deficits and hearing loss were analyzed.
Results. The 5-year overall survival and survival without progression were 69% and 62% respectively. A better overall outcome: survival and progression-free survival rates were observed, for patients who were treated with 3D radiotherapy 1997–2005, but this was not a statistically significant difference. As calculated by multivariate analysis an age of less than 4 years had was associated with a significantly worse outcome. There were no significant influences of other factors such as extent of resection, leptomeningeal spread, sex and neurological condition patients, tumour grade, location and size. In the analysis of patterns of failure no statistical significant differences between incidence dissemianation after craniospinal radiation versus local irradiation were observed. The probability of late effects such as cognitive and growth dysfunction in the patients treated with 2D irradiation were observed twice as much than with those after 3D irradiation. More frequently impairment of intellectual function in children younger than 4 years and more growth dysfunction in children under the age of 9 years were observed.
Conclusion. The results of combined treatment of the children with intracranial ependymoma, obtained in our Radiotherapy Department are comparable to those published in other centers. The use of 3D conformal radiotherapy causes a trend towards improvement in outcome. The improvement of treatment results after 1997 is due to advances in diagnosis and treatment. The use of conformal local irradiation does not increase the risk of spreading disease and reduces incidence late complications.