Pediatric CNS Imaging and long-Term Effects of CNS Irradiation in pediatric oncologic patients.

BACKGROUND Aim of this study was to retrospectively evaluate changes in the central nervous system (CNS) post irradiation detected in Magnetic resonance (MR) imaging. METHODS MR images of 15 children with CNS tumors, treated through whole brain irradiation over 10 years were retrospectively reviewed. Variables, such as age at the time of irradiation, total radiation dose, treatment length and time interval between irradiation and MR changes were evaluated. RESULTS All patients included in the study had imaging abnormalities of the CNS. Eight patients (53 %) developed CNS abnormalities within a short period of time - only a few months after irradiation (mean 4.8 months), seven patients (47 %) developed CNS abnormalities within a long-time interval after treatment (mean 4.6 years). At almost all patients, a T2 -increase of supra- and infratentorial white matter was observed. Follow up examinations showed nine patients (60 %) with cerebellar atrophy. CONCLUSIONS Within this sample of pediatric patients, who underwent whole brain irradiation, the irradiation length (time receiving irradiation) was not related with the severity of the MR changes. Besides, a correlation between the age of the child or the length of the radiotherapy and the extent of the changes could not be confirmed. However, we observed a trend towards stronger brain parenchymal degeneration with cystic changes in the younger age group of children in our sample. Older children that received irradiation seem to be more susceptible to vascular dysplasia with cavernous hemangiomas and microbleedings.