MRI showing large frontal meningioma
Surgery for Meningioma
Meningiomas make up 15-20% of all primary brain tumors. They are usually benign and slow growing (only 6 - 8% are malignant.) The standard treatment is surgery and if complete surgical removal is possible, the relapse rate is only about 7 - 10%. About one third cannot be completely removed and risk of relapse is much higher ( 30 - 69%.) In these cases postoperative radiation will reduce the risk of a relapse to about 10 - 32%. In other data the local control rate at 5 years after subtotal resection (i.e. incomplete surgery) was 43-59% after surgery alone versus 77 - 89% after surgery + postOp radiation. For unresectable meningiomas, radiation alone may control the tumors in 92 - 97% of the cases.
For surgical relapses, most patients have additional surgery but radiation alone may control the tumor in 50-89% of the cases.
In a large series 94% of all meningiomas were benign, 5% atypical and 1% were malignant. The five-year recurrence rates after presumed complete resection for benign, atypical, and anaplastic meningiomas were 3, 38, and 78 percent, respectively. For malignant meningiomas, all patients should have radiation after surgery and even then the control rate is only 35 - 48%. Most patients with atypical meningioma are also offered postOp radiation. See the treatment guidelines from the NCCN here and their dose recommendations here