Conventional MRI at presentation does not predict clinical response to radiation therapy in children with diffuse...

Diffuse pontine glioma is a pediatric brain tumor with a median survival time of 1 year and few long-term survivors. Conventional MRI has not been shown to predict overall survival. With this dismal prognosis, clinical improvement after radiation therapy might be a more relevant issue.

To determine whether initial imaging would predict clinical response.

We performed a retrospective review of children with diffuse pontine glioma treated at The Children's Hospital, Denver, and the University of Colorado-Denver from 1995 to 2008. The 30 children were divided into two groups based on acute clinical response to radiation therapy. Quantitative measurements on presenting MRIs were compared between the groups.

Seven of 30 children did not respond to radiation therapy. There were no statistically significant differences in initial imaging characteristics between responders and non-responders. Necrosis and enhancement were more common in responders. Tumor surrounding the basilar artery, compression of the 4th ventricle and extension to the cerebellum were more common in non-responders.

Conventional MRI at presentation does not predict clinical response in children with diffuse pontine glioma. Additional studies with larger numbers of patients and other imaging modalities are needed.