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

I Cuba, tumors of the Central Nervous System (CNS) for children and adolescents account between 18 and 20% of all tumors in this group of age.1-3 The main methods of treatment are surgery, radiotherapy, and chemotherapy.4 Radiation therapy is a major treatment avenue in medulloblastomas, primitive neuroectodermal tumor (PNET) in some cases of germinomas consist of craneospinal irradiation (CS ), and a supplementary boost to the post-operative tumor bed, followed by chemotherapy. In ABSTRACT Objective 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.