Use the timing after radiation and the low-perfusion enhancement pattern to separate radiation necrosis from recurrence, and watch for the transient focal deficits that point toward SMART syndrome. The management issue is to avoid mistaking late treatment injury for active tumor.

Radiation necrosis usually appears months after therapy and can enhance with low perfusion; SMART syndrome causes stroke-like migraine attacks with reversible deficits; Late radiation injury also includes leukoencephalopathy, atrophy, and vascular damage; Radiation myelopathy often appears one to three years later; Optic nerve damage from radiation causes delayed painless visual loss