Detailed Description:

Following radiation and immunotherapy, many pediatric participants with high-grade gliomas (HGG), including diffuse midline glioma (DMG), demonstrate radiographic findings suspicious of disease progression. Differentiating post-treatment changes from true tumor progression is paramount to clinical decision-making, as true tumor progression may warrant a change in treatment, while post-treatment changes are typically not an indication to change treatment. Unfortunately, conventional MRI cannot reliably distinguish between true progression and post-treatment changes. Therefore, finding a physiological correlate to delineate true progression from pseudo-progression is critical. The overall objective of this current application is to evaluate 18F-fluciclovine PET imaging as a diagnostic biomarker for tumor progression compared to post-treatment changes in pediatric HGG. The long-term goal of this research is to accurately differentiate tumor progression from post-treatment changes in pediatric HGG using 18F-fluciclovine PET imaging.}}