Treatment related DTI changes in the posterior thalamic radiation in survivors of childhood posterior fossa tumors

Advances in the treatment of cancer, including surgery, chemotherapy and radiation therapy, have led to an increase in the survival rate of children with brain tumors. However, the efficacy of these therapies is often overshadowed by the long term neurological consequences of treatment-induced injuries. Diffusion weighted imaging, a magnetic resonance imaging technique, allows us to measure changes in white matter in a population of posterior fossa brain tumor survivors who had two different treatment schemes: surgery + chemotherapy (S+C) and surgery, chemotherapy + cranial irradiation (S+C+R). The results of our analysis reveal significantly lower mean diffusivity (MD) and lower radial diffusivity (RD) values in the posterior thalamic radiation in the S+C+R group, which may indicate more myelin or more axonal damage in the S+C group compared to the S+C+R group. While it is possible that this may be related to a more intensive chemotherapeutic regimen in the S+C group, more work will be forthcoming to produce a clearer picture of treatment-related injury in survivors of posterior fossa tumors in childhood. These preliminary findings will be further analyzed to include demographic factors, neuropsychological data, and radiation dose values.