NIMG-91. DOTATATE PET/MR-GUIDED POSTOPERATIVE MANAGEMENT IN WHO-2 MENINGIOMA: ACTIVE SURVEILLANCE BASED ON PET/MR EVIDENCE OF GROSS TOTAL RESECTION

Abstract BACKGROUND MRI, the standard of care (SOC) for meningioma radiotherapy planning, lacks sensitivity postoperative small volume disease and osseous or parenchymal invasion. BN003 (NCT03180268) randomizes patients with WHO-2 meningiomas MRI-determined GTR to observation 60 Gy IMRT resection bed. More sensitive specific imaging biomarkers may improve clinical outcomes in by limiting unnecessary radiation normal tissues improving targeting. [68Ga]-DOTATATE is a PET radiotracer targeting somatostatin receptor 2 (SSTR2), highly biomarker. We developed dedicated DOTATATE brain PET/MRI protocol allowing differentiation from post-treatment change, using SUV analysis Patlak modeling. Our prospective observational trial (NCT04081701) has imaged over 90 meningioma. This IRB-approved study evaluated PFS tumors who were managed solely active surveillance. hypothesized that surveillance would be higher than GTR, NRG-BN003’s arm (randomized comparing fractionated radiotherapy) as reference standard. METHODS 92 SSTR2-positive neoplasms enrolled between 9/2019 5/2022 according our previously published protocol. 8 met inclusion criteria (WHO-2 & PET/MR GTR) followed SOC MRI. Kaplan-Meier survival was performed. RESULTS 5/8 subjects (62.5%) women; mean age 67 years. MRI follow-up data available 19.75 months (range: 7-38 months). One subject (12.5%) progressed at 21 months; remainder remain progression-free. demonstrated 3-year 80%, which substantially reported 69% literature. CONCLUSIONS can specificity imaging-based assessment extent meningiomas.