Fig. 2

Axial post-contrast T1WI demonstrating a left cingulate gyrus metastasis (a, dotted circle) from a breast carcinoma primary, treated with 20 Gy single-fraction SRS. At 18-month follow-up (b), the metastasis had decreased in size, but a new peripherally-enhancing lesion had developed in the splenium of the corpus callosum (arrow); there was also new, subtle enhancement (arrowhead) in the right cingulate gyrus at this time. The abnormalities continued to evolve – another 19 months later (c), the splenial component had resolved, while the right cingulate gyrus component had mildly enlarged. The appearances stabilized thereafter, consistent with RN