Differentiation between brain radiation injury and brain tumor recurrence

Brain radiation injury is a severe complication of radiation therapy for cancer. A major dilemma in the diagnosis of radiation injury is differentiating it from recurrent tumor. MR diffusion-weighted imaging, MR spectroscopy, PET and SPECT have all been used in an attempt to differentiate the two. But none of them shows the best diagnosis sensitivity or specificity. Biopsy and histology may be considered the ultimate diagnosis tests.