Contrast-Enhanced Perfusion MR Imaging to Differentiate Between Recurrent/Residual Brain Neoplasms and Radiation Necrosis

Purpose: To determine the value of dynamic susceptibility contrast enhanced (DSC) MRI (magnetic resonance imaging)perfusion in the characterization of newly developed/enlarging lesions within irradiated regions after treatment of braintumors. Methods: This prospective cross-sectional study covered 23 patients, 12 females and 11 males. All casesinitially presented with histologically proven malignant brain tumors and underwent surgical intervention followed byradiotherapy (+/- chemotherapy). On follow up imaging, they presented with newly developed/progressively enhancingmass lesions at the sites of the primary tumors. All patients then underwent conventional MRI, DSC MRI perfusionand MR spectroscopy. Results: In our study, we found DSC MR perfusion to be a useful non-invasive method fordifferentiating recurrent brain tumors from radiation necrosis. This approach allows hemodynamic measurements tobe obtained within the brain as the relative cerebral blood volume (rCBV) to complement the anatomic informationobtained with conventional contrast enhanced MR imaging. The sensitivity and specificity of DSC MR perfusionfor differentiation were found to be 77.8% and 80.0%, respectively. Conclusion: DSC MR perfusion is a promisingtechnique in differentiating recurrent brain tumors from radiation necrosis as it has acceptable spatial resolution andcan be routinely performed in the same settings after conventional MRI.