The role of imaging for the management of newly diagnosed glioblastoma in adults: a systematic review and evidence-based clinical practice guideline update

Target population These recommendations apply to adults with a newly diagnosed lesion with a suspected or histopathologically proven glioblastoma (GBM). Question What are the optimal imaging techniques to be used in the management of a suspected glioblastoma (GBM), specifically: which imaging sequences are critical for most accurately identifying or diagnosing a GBM and distinguishing this tumor from other tumor types? Recommendations Critical Imaging for the Identification and Diagnosis of Glioblastoma Level II: In patients with a suspected GBM, it is recommended that the minimum magnetic resonance imaging (MRI) exam should be an anatomic exam with both T2 weighted, FLAIR and pre- and post-gadolinium contrast enhanced T1 weighted imaging. The addition of diffusion and perfusion weighted MR imaging can assist in the assessment of suspected GBM for the purposes of distinguishing GBM from other tumor types. Computed tomography (CT) can provide additional information regarding calcification or hemorrhage and also can be useful for subjects who are unable to undergo MR imaging. At a minimum, these anatomic sequences can help identify a lesion as well as its location, and potential for surgical intervention. Improvement of diagnostic specificity with the addition of non-anatomic (physiologic imaging) to anatomic imaging Level II: One blinded prospective study and a significant number of case series support the addition of diffusion and perfusion weighted MR imaging in the assessment of suspected GBM, for the purposes of distinguishing GBM from other tumor types (e.g., primary CNS lymphoma or metastases). Level III: It is suggested that magnetic resonance spectroscopy (MRS) and nuclear medicine imaging (PET 18F-FDG and 11C-MET) be used to provide additional support for the diagnosis of GBM.