RADT-35. A PROSPECTIVE REGISTRY STUDY OF 68GA-DOTATATE PET INCORPORATION INTO TREATMENT PLANNING OF INTRACRANIAL MENINGIOMAS

Abstract Introduction The current standard for meningioma radiation planning involves MRI-based image guidance. SSTR ligands such as 68Ga-DOTATATE are being explored radiotherapy treatment due to universal expression of somatostatin receptor 1/2 in tissue. We hypothesize that PET utilization can reduce the risk local failure (LF) through precise and may also suggest patients who have avidity after a perceived GTR be poor observation candidates. METHODS A single institution prospective registry study was created included intracranial received scan assist with oncologist decision-making. These were ordered all departmental standard. Patients from 1/1/2018-2/25/2022 eligible inclusion. RESULTS 60 treated this registry. 22%, 72%, 7% World Health Organization (WHO) high, intermediate, low-risk, respectively. After completing their scan, 48, 11, 1 patient(s) proceeded RT, observation, or redo craniotomy. median follow up 16 months (IQR 8.3-23.1). 3 (5%) experienced LF between 9.2-28.5 diagnosis. 2 had PET-avid disease post-operative cavity elected prior recurrence, high-risk patient multifocal years second course multiple previous recurrences. rates 0%, 8% low, cohorts, There no Grade higher toxicities attributed PET-guided radiation. CONCLUSION This is largest known population followed by physicians utilized guided therapy. Only receiving therapy, likely radioresistant histology. Incorporating into future trials clinician decision-making improve outcomes.