CNSC-04. EVALUATING LONGITUDINAL WORKING MEMORY PERFORMANCE IN PEDIATRIC PATIENTS WITH CRANIOPHARYNGIOMA VIA FMRI

Craniopharyngioma is a type of benign brain tumor that develops in the suprasellar region of the brain and can lead to long-term neurological, endocrine, and visual impairments as well as neurocognitive deficits resulting from the tumor and its treatment. The contemporary treatment options for this tumor are radical surgery or limited surgery in conjunction with radiotherapy. The current understanding of the impact of brain injury related to the tumor and its treatment such as proton radiotherapy (PRT) on neurocognitive function is limited.

The study (NCT01419067) was approved by the IRB and informed consent was obtained from patients or their parents. Functional magnetic resonance imaging (fMRI) was performed in a 3T MRI imaging system (Siemens MAGNETOM Prisma, Erlangen, Germany) and used to evaluate the neurocognitive performance of 58 pediatric patients (31 females and 27 males) before and after proton radiotherapy (PRT). The patients underwent serial imaging at four-time points (baseline, 18, 36, and 60 months after PRT) and performed a working memory (0-back, 1-back, and 2-back) task-based fMRI. A full factorial model was used for longitudinal group analysis at different time points through statistical parametric mapping. Omission errors, commission errors, and reaction time were measured for each task.

The results showed robust detection of the working memory network with increased activation (FDR<0.05) in the precuneus, mid-temporal gyrus, and angular gyrus at 36 months compared to 18 months. The behavioral test results showed a gradual decrease in omission errors in the 2-back task group and an increase in reaction time for all three task groups over time.

These findings suggest that PRT has a transient effect on brain activation and behavioral performance, potentially indicating improved executive functioning, recovery from the mass effect of the tumor and/or surgery, and the minimal negative impact from PRT.