Reirradiation of Recurrent Tumors in Central Nervous System in Children and Adolescents

Abstract

To report the epidemiology and associated health factors of children and adolescents who were subject to several rounds of
irradiation at the National Institute of Oncology and Radiobiology in Havana, Cuba
Introduction
Irradiation is often an integral part of the treatment for central nervous system tumors. However, it is particularly challenging
to use for the treatment of pediatric and adolescents, as it has been predicted to have drastic effects on the developing brain.
Recurrence is frequent and treatment is limited with a few management options. These patients often underwent several parallel
treatments including surgery and chemotherapy.
Material and Methods
A retrospective, observational study was conducted for 17 children and adolescents aged 3 to 18-years, who had central nervous
system tumor recurrences and were reirradiated with a linear accelerator, three dimensional (3D) planning with a dose range of
36-56 Gy. Survival functions were estimated by Kaplan-Meier method.
Results
The study included eight medulloblastomas, (47.1%); two germinomas, (11.8%); three astrocytomas grade III, (17.6%); two
brainstem tumors, (11.8%); one ependymoma, (5.9%) and one oligodendroglioma, (5.9%). All the patients responded to the
treatment, with survival rates of 62.5% and 25 % at 1 and 2-years, respectively. The median survival time after reirradiation
was 1.13-years. The median interval between radiation courses was 4.7-years. Median age at the first course of radiotherapy was
9-years, and at the second irradiation 14-years. Median total dose for the 2 irradiation courses were 100 Gy. Five patients are
still alive with a survival time range of 7.5 and 0.9-years. The cognitive function in surviving patients was preserved, especially
for over 12-years of age. Three had a Karnofsky-Lansky (K-L) scale of 100%, and two patients had a K-L of 90% and 70%,
respectively.
Conclusions
Reirradiation is an option to be considered in patients with relapsed tumors in order to extend survival time, with a good cognitive
functions.