I've had a craniotomy and am now on watch-and-wait for 2 other meningiomas. Benign meningiomas typically grow only 1 to 2 millimeters a year. (I was told by a radiation oncologist.) So with annual MRIs one can safely watch-and-wait ad infinitum unless (1) the meningioma, even a smaller one, is pressing on nerves or other brain structures causing symptoms that one determines is is compromising their quality of life, and (2) keep in mind if this benign tumor (85% of the time, I'm quoting bfschemikerin-my own oncologist referenced 90%) keep in mind that if the meningioma is not in a location conducive to resection (removal) then your window for radiation therapy closes somewhere between 3 and 4 millimeters of growth.