Atypical meningiomas are tumors that originate in the meninges and are associated with a high risk of recurrence. Until now, it was unclear whether patients benefit from radiotherapy after complete surgical removal of the tumor. An international study in which MedUni Vienna played a key role provides new evidence that radiotherapy can significantly reduce the recurrence rate. The results, recently published in The Lancet, are set to be incorporated into national and international guidelines.