title: From the clinician's point of view - What is the status quo of positron emission tomography in patients with brain tumors?
abstract: The most common type of primary brain tumor is malignant glioma. Despite intensive therapeutic efforts, the majority of these neoplasms remain incurable. Imaging techniques are important for initial tumor detection and comprise indispensable tools for monitoring treatment. Structural imaging using contrast-enhanced MRI is the method of choice for brain tumor surveillance, but its capacity to differentiate tumor from nonspecific tissue changes can be limited, particularly with posttreatment gliomas. Metabolic imaging using positron-emission-tomography (PET) can provide relevant additional information, which may allow for better assessment of tumor burden in ambiguous cases. Specific PET tracers have addressed numerous molecular targets in the last decades, but only a few have achieved relevance in routine clinical practice. At present, PET studies using radiolabeled amino acids appear to improve clinical decision-making as these tracers can offer better delineation of tumor extent as well as improved targeting of biopsies, surgical interventions, and radiation therapy. Amino acid PET imaging also appears useful for distinguishing glioma recurrence or progression from postradiation treatment effects, particularly radiation necrosis and pseudoprogression, and provides information on histological grading and patient prognosis. In the last decade, the tracers O-(2-[(18)F]fluoroethyl)-L-tyrosine (FET) and 3,4-dihydroxy-6-[(18)F]-fluoro-L-phenylalanine (FDOPA) have been increasingly used for these indications. This review article focuses on these tracers and summarizes their recent applications for patients with brain tumors. Current uses of tracers other than FET and FDOPA are also discussed, and the most frequent practical questions regarding PET brain tumor imaging are reviewed.
authors.affiliation: Department of Neurology, University of Cologne, Cologne, Germany (N.G.); Research Center Jülich, Institute of Neuroscience and Medicine, Jülich, Germany (N.G., K.-J.L.); Center of Integrated Oncology (CIO), University of Cologne, Cologne, Germany (N.G.); Department of Nuclear Medicine, University of Aachen, Germany (K.-J.L.); Department of Radiological Sciences, David Geffen School of Medicine at UCLA., Los Angeles (W.B.P.).
authors.forename: Norbert
authors.initials: N
authors.lastname: Galldiks
authors.affiliation: Department of Neurology, University of Cologne, Cologne, Germany (N.G.); Research Center Jülich, Institute of Neuroscience and Medicine, Jülich, Germany (N.G., K.-J.L.); Center of Integrated Oncology (CIO), University of Cologne, Cologne, Germany (N.G.); Department of Nuclear Medicine, University of Aachen, Germany (K.-J.L.); Department of Radiological Sciences, David Geffen School of Medicine at UCLA., Los Angeles (W.B.P.).
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Langen
authors.affiliation: Department of Neurology, University of Cologne, Cologne, Germany (N.G.); Research Center Jülich, Institute of Neuroscience and Medicine, Jülich, Germany (N.G., K.-J.L.); Center of Integrated Oncology (CIO), University of Cologne, Cologne, Germany (N.G.); Department of Nuclear Medicine, University of Aachen, Germany (K.-J.L.); Department of Radiological Sciences, David Geffen School of Medicine at UCLA., Los Angeles (W.B.P.).
authors.forename: Whitney B
authors.initials: WB
authors.lastname: Pope
mesh_terms: D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D005910:Glioma / Q000000981:diagnostic imaging; D006801:Humans; D049268:Positron-Emission Tomography
keywords: FDOPA; FET; MET; MRI; PET