IMG-09. DETERMINING OPTIMAL IMAGING SCHEDULE FOR PLGG AND PHGG PATIENTS OFF-THERAPY

To this point there is no standard imaging schedule across all institutions in the surveillance of pediatric low-grade gliomas (pLGG) and pediatric high-grade gliomas (pHGG) after therapy completion. We at our institution use the Children’s Oncology Group (COG) protocols ACNS1831/ACNS1833 to guide our surveillance of pLGG. The MRI schedule is every 3 months for year 1 (after therapy), every 6 months for years 2 and 3, and annually for years 4 and 5. For pHGG we do MRI imaging every 3 months for year 1, every 4 months for year 2, every 6 months for years 3-5, and annually for years 6-10. It is uncertain if this imaging schedule is optimal in terms of tracking tumor evolution post-treatment. pLGG are a diverse group of tumors but generally tend have a slower progression rate when compared to pHGG. Studies have shown a 5-year progression-free survival (PFS) of 45% to 65% for residual tumor of any size for pLGG. 3-year PFS for pHGG at best is 18%. When possible, spacing imaging, decreasing sedations, and decreasing gadolinium-based contrast agents that can deposit in the body are key drivers in imaging schedules. Through retrospective analysis we are establishing if imaging schedules should be adjusted based on disease progression or recurrence.