I had CyberKnife, first cousins. The GammaKnife requires a helmet/band kind of thing to keep your head from moving. As I understand it, some prong like thinks attach to your skull . CK used a mesh mash, made to fit my face, was attached to the table. The “radiation “ might be different IDK. I had 3 treatments for an acoustic neuroma, and it eventually took my hearing in that ear. But the tumor shrunk and is stable. Hubs had CyberKnife for prostate cancer, that’s a whole different ball game. The sessions lasted about an hour if I recall (2014). They let me bring my own music to listen to. Hope this helps.

I experienced more balance issues after, chose balance PT over steroids. It was a good choice. And fatigue for a couple months, maybe more, don’t remember for sure.