The objectives of our proposed study are to (a) evaluate the feasibility of conducting a structured exercise program in children treated with cranial radiation for brain tumors, (b) test whether exercise results in improved thinking skills and emotional function, and (c) examine potential mechanisms of improved outcome, particularly recovery of white matter and grey matter.

Brain tumors are the leading cause of death and disability from childhood disease in developed countries. With treatment advances over the last 25 years, survival rates have improved dramatically. However, survival is often achieved at considerable cost. Cranial radiation is frequently required for effective tumor control, and is associated with significant neuro-toxicity, including white matter damage and cognitive morbidity. In order to achieve the best possible outcome for survivors, and ultimately conquer the long-term consequences of this disease, new interventions must be developed to ameliorate the neuro-toxic effects experienced by children. radiation injury can now be used to guide the development of interventions designed to rescue neural tissue. Furthermore, various new agents and activities with potential to stimulate neuro-recovery are now available. The potential value of exercise for rescuing the brain from neuro-toxic effects, for instance, has recently been reported. Next, neuro-cognitive processes that are particularly sensitive to the effects of cranial radiation have been identified and can serve as behavioral assays to test the effectiveness of these new interventions. Finally, novel neuro-imaging tools are available to perform in vivo evaluations in order to delineate potential mechanisms of neuro-recovery. We intend to integrate these new research findings to develop and evaluate a physical exercise-based intervention targeted at rescuing brain tissue of children with brain tumors from the neuro-toxic impact of cranial radiation.

Inclusion Criteria:

• Survivors will be included if they are between 7 and 17 years of age.
• Survivors will be included if they either declare English as their native language or have had at least two years of schooling in English at the time of their first assessment.
• Survivors must have been diagnosed with a hemispheric or posterior fossa tumor and been treated with cranial spinal radiation.
• Survivors no more than 10 years may have elapsed between diagnosis and time of study.
• Survivors with a shunt will be included in the study, but will need to be identified prior to study on-set to discuss any specific considerations for imaging and physical activity.

Exclusion Criteria:

• are younger than 7 years (the delivery of an intervention program to young children carries challenges that make it difficult to include in an initial feasibility grant) or older than 17 years
• require sedation for MRI imaging
• is claustrophobic
• have severe neurological/motor dysfunction that would preclude safe participation in an exercise program.