IMG-92. An evidence-based framework for postoperative surveillance of meningioma

Abstract Meningiomas frequently recur after surgery. Existing guidelines for postoperative surveillance are based on customary practices or limited data. This may result in excessive or inadequate surveillance. We compared 8 studies involving 1,519 resected meningiomas with postoperative follow up ranging from 7 to 23 years. Meningiomas were stratified using the World Health Organization and Simpson grading systems, and progression free survival data were compared. Recurrence patterns were validated using two additional studies involving 2,463 meningiomas. Incompletely resected meningiomas of all grades displayed recurrences throughout the observation period. The 5-year and 10-year cumulative incidence of recurrence for completely resected Grade 1 meningiomas were 10% and 20%, with no recurrences beyond 11 years. For completely resected Grade 2 meningiomas, the 5-year and 10-year cumulative incidence of recurrence were 24% and 50%, with ongoing recurrences throughout the observation period. Elevated recurrence rates for Grade 1/2 meningiomas persisted beyond 5 years. For completely resected Grade 3 meningiomas, the 5-year cumulative incidence of recurrence was 63%, and all recurred before 10 years. Postoperative MRI at 48 hours to determine extent of resection and at 4 months to detect rapid regrowth are recommended. For completely resected Grade 1 meningiomas, annual MRI followed by discontinuation of surveillance if there is no recurrence after 11 years is reasonable. For completely resected Grade 2 meningiomas, annual MRI indefinitely is recommended. For Grade 3 meningiomas, MRI every 3-4 months for 2 years, followed by every 6 months indefinitely, is recommended. Incompletely resected meningiomas should be followed indefinitely.