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

Abstract

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