A recurring question in treatment decision making for patients after radiation (with or without chemotherapy) is differentiation of recurrence versus treatment effect.  Both nCBV and kTrans have been utilized to answer this question.  Using our internally determined threshold values (pathology as the gold standard) we have a specificity of 100%, PPV of 100%, NPV of 69%, and sensitivity of 44%, (n=79) in distinguishing these two entities.