50-year-old man with biopsy-proven renal cell carcinoma to the right internal acoustic meatus (IAM). He was treated with 2500 cGy in 5 stages. (A) Axial MRI with contrast prior to radiosurgery showing the tumor at the IAM. White arrow: tumor. (B) Axial MRI with contrast 5 months after radiosurgery showing extension of disease cephalad. This area was treated with an additional 2400 cGy in 3 stages. White arrow: tumor extension.