Impact of 2021 World Health Organization Grading, Peritumoral Edema, and Radiotherapy on the Recurrence of a Grossly Resected Intracranial Meningiomas: A Ten-Year Follow-Up Study.

Background: The significance of histological grading and peritumoral edema (PTE) in predicting intracranial meningioma recurrence among Saudis is often neglected. This study aimed to evaluate the impact of these factors over a 10-year follow-up period.

Methods: A retrospective cohort of 124 patients with intracranial meningioma was analyzed over the period from 2011 to 2021. All patients underwent gross total resection (GTR) of the tumor. Post-surgical radiotherapy (RT) was offered to patients with grade II-III meningiomas. The impact of histological grading, PTE, and RT on the recurrence-free interval (RFI) was investigated.

Results: The mean age of the patients was 49 years (range: 18 - 84), with 87 females (70.2%) and 37 males (29.8%). Most tumors (88.7%, n = 110) were supratentorial, while 11.3% (n = 14) were infratentorial. The World Health Organization (WHO) grading classified 101 tumors (81.5%) as grade I, 17 (13.7%) as grade II, and six (4.8%) patients as grade III. Grading was significantly associated with RFI (P = 0.013), with grade I meningiomas having the slowest recurrence. The overall recurrence rate was 16.9%, with 38.1% (n = 8) of grade I and 61.9% (n = 13) of grade II-III meningiomas recurring within 5 years post-GTR and RT. There was no significant difference in RFI between RT-exposed and non-exposed patients (P = 0.15). PTE was present in 76 cases (61.3%) and absent in 48 (38.7%), significantly affecting RFI (P = 0.014), with shorter RFI in PTE cases. Overall, 95.2% (n = 118) of patients survived, while 4.8% (n = 6) died; five had grade II-III, and one had grade I meningioma.

Conclusions: Totally, resected intracranial meningiomas with grade II-III features and PTE were associated with earlier tumor recurrence and poorer patient survival. Post-surgical RT had an insignificant effect on the RFI.