Advanced Neuroimaging for Brain Tumors: Post-Radiation Therapy Assessment with T2*-Weighted Dynamic Susceptibility Contrast MRI
摘要
Conventional contrast-enhanced MRI is very limited in its ability to differentiate tumor from post-treatment radiation effect (PTRE) in brain tumor patients following radiation therapy. T2*-weighted dynamic susceptibility contrast (DSC) perfusion MRI is a well-established method of advanced functional imaging that can provide valuable additional information in the form of relative cerebral blood volume (rCBV) to differentiate these entities. It is common to think of new or enlarging contrast-enhancing lesions in the post radiotherapy setting as either all PTRE or all tumor, when they are often actually composed of an admixture of them. A more recent application of DSC-MRI called fractional tumor burden (FTB) is able to provide quantitative information of the amount of PTRE vs. tumor in any such lesion. While there is some evidence that rCBV may predict outcome in brain tumor patients, larger, well-designed clinical trials are needed to validate rCBV as a biomarker to predict survival. In addition, more standardization of technique as well as knowledge of the precision of DSC-MRI is needed for more widespread adoption of this useful imaging method beyond academic centers.