Current concepts in brain tumor imaging.
Magnetic resonance imaging (MRI) is the most useful imaging tool in the evaluation of patients with brain tumors. Most information is supplied by standard anatomic images that were developed in the 1980s and 1990s. More recently, functional imaging including diffusion and perfusion MRI has been investigated as a way to generate predictive and prognostic biomarkers for high-grade glioma evaluation, but additional research is needed to establish the added benefits of these indices to standard MRI. Response critieria for high-grade gliomas have recently been updated by the Response Assessment in Neuro-Oncology (RANO) working group. The new criteria account for nonenhancing tumor in addition to the contrast-enhancing abnormalities on which older criteria relied. This issue has recently come to the fore with the introduction of the antiangiogenic agent bevacizumab into standard treatment for recurrent glioblastoma. Because of its potent antipermeability effect, contrast enhancement is markedly reduced in patients who receive bevacizumab. The RANO criteria also address the phenomenon of pseudoprogression, in which there may be transient MRI worsening of a glioblastoma following concurrent radiotherapy and temozolomide.
From Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA; David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA; University of California, San Francisco, Department of Neurological Surgery, San Francisco, CA.
Andrew D
AD
Norden
From Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA; David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA; University of California, San Francisco, Department of Neurological Surgery, San Francisco, CA.
Whitney B
WB
Pope
From Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA; David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA; University of California, San Francisco, Department of Neurological Surgery, San Francisco, CA.
Susan M
SM
Chang