The Gamma Knife Perfexion surgery at MyMichigan Medical Center Midland is a revolutionary device that uses highly targeted radiation to treat brain conditions such as: brain tumors, acoustic neuroma, arteriovenous malformation (AVM), essential tremor, meningiomas, and trigeminal neuralgia. Gamma Knife surgery treats both benign (non cancerous) and malignant (cancerous) brain tumors - including multiple metastases.