Fig. 5

This patient had previously undergone resection of a left temporal melanoma metastasis and cavity SRS at an external institution (radiation dose-fractionation unclear), followed by intensity-modulated RT (20 Gy in 5 fractions) for localized leptomeningeal recurrence about two years later. Coronal post-contrast T1WI performed 15 months after the last episode of irradiation demonstrates separate (non-contiguous) areas of enhancement (arrowheads) around the left Sylvian fissure. The distribution, morphology and non-contiguous nature of this enhancement, conforming to the RT field, suggests RN, which was confirmed by subsequent regression