FIG 2. Patient 11.

A–C, Serial contrast-enhanced gradient echo-images (26/6/1) and PRESS spectra (1000/144/1; voxel resolution, 1.0 cm³) over the gamma knife target 3 days before (A) and 1 month (B) and 4 months (C) after radiosurgery. Two representative voxels are depicted, with the 15-Gy isodose line shown in red. The anterior voxel received an average radiation dose of 19.0 Gy, while the posterior voxel received 10.3 Gy. Reductions in both Cho and NAA as well as an increase in lactate/lipid are noted 1 month after radiosurgery. At 4 months, the less-irradiated voxel has developed a distinct tumorlike spectral pattern, while the heavily irradiated voxel appears necrotic. The lesion was resected, and brachytherapy seeds were implanted shortly after the last examination shown, but no biopsy samples were taken. The patient died 13 months after undergoing gamma knife treatment.