After resection, malignant gliomas are routinely treated with adjuvant radiotherapy and temozolomide. The efficacy of these therapies has led to an increasing incidence of pseudoprogression and radiation necrosis, treatment-related effects that resemble tumor progression or recurrence on gadolinium-contrast MRI. The authors of this Review discuss the prognostic importance of accurate diagnosis of these post-treatment lesions, and the use of advanced imaging modalities for this purpose.
