Clinical efficacy of adjuvant radiotherapy for WHO grade II intracranial meningioma

Background: Maximal surgical resection remains the treatment of choice for grade II meningiomas, and for some authors to be sufficient to guarantee a long indolent course even without post-surgical radiotherapy (RT), but there is no consensus on the use of RT in this patient population. Methods: We retrospectively compared clinical and radiological outcome between WHO grade I (group A) and grade II (group B) surgically-treated meningiomas, focusing on the role of adjuvant RT. We registered clinical, surgical and radiological data to detect differences in survival and functional outcome between the two groups. Results: The final cohort consisted of 284 patients for group A and 94 patients for group B. Group B showed a higher risk of developing recurrence independently of the EOR (7,75% for Group A versus 27,7% for Group B, p=0.01). Patients who did not undergo adjuvant RT documented recurrence in 50% of cases, compared with 19% of patients who underwent RT (p=0.024). There is a weak difference in the risk of developing postoperative seizures in the group submitted to radiotherapy (p=0.08). Performance status remained stable for both groups, but for group B tended to decrease significantly after 1 year with regard to EOR and RT. Conclusions: Recurrence is more frequent for Grade II meningiomas, even though there are not significant differences in terms of complications and functional outcome. Radiotherapy in grade II meningiomas does indeed lead to better control of recurrence, however, leading to an increased risk of seizures and reduced performance status.