@doyel: I see it's been 6 days since you posted so I'll weigh in since no one else has. My neurologist told me they don't like to use gamma or cyber knife once the meningioma grows to about 3 centimeters. The radiation specialist I was referred to verified this. But I've read on this Mayo Connect platform that others say 4 to 5 cm. I don't know where they got their information.