A task-fMRI study in adolescent and adult survivors of childhood cancer

Long-term survivors of childhood cancer may experience neurocognitive late effects, yet how they engage neural systems during cognitive tasks remains poorly characterized. In this exploratory study, we examined task-evoked activation during a Flanker functional MRI (fMRI) task in 21 adolescent and adult survivors of childhood cancer with prior chemotherapy exposure and 21 healthy controls under congruent and incongruent conditions. Whole-brain group comparisons were conducted for each condition, and group-by-condition interactions on reaction time and accuracy were examined. We also examined exploratory associations between this contrast and cognitive performance. Relative to controls, survivors showed longer reaction times in both conditions and lower NIH Toolbox Flanker scores, with comparable accuracy. Survivors showed reduced activation in the bilateral inferior frontal gyri, the supplementary motor area, and the bilateral caudate, and increased activation in the right inferior temporal and cerebellar regions. The incongruent > congruent contrast was associated with greater activation in the orbitofrontal cortex, inferior temporal gyri, and fusiform gyrus. The findings are hypothesis-generating and require replication in larger, treatment-informed, longitudinal studies before clinical inferences can be drawn.