Amino acid PET and magnetic resonance spectroscopy (MRS) are at the forefront of noninvasive imaging techniques used for detection and subtyping of glioma-suspicious lesions. In this pilot study, we compare L-methyl-11C-methionine PET and MRS for their ability to predict glioma subtypes.
Nineteen patients with histologically, confirmed newly diagnosed glioma underwent preoperative L-methyl-11C-methionine PET and MRS in 1 diagnostic session. According to the molecular portfolio and histopathologic diagnosis, patients were subdivided in isocitrate dehydrogenase (IDH) wild-type glioblastoma, IDH wild-type grade II/III glioma, IDH-mutant grade II/III glioma without 1p/19q codeletion, and with 1p/19q codeletion subgroups. Maximum tumor-to-brain ratio (TBRmax), creatine, choline, and N-acetyl aspartate peaks were correlated with postoperative histopathologic tumor diagnoses.
Maximum tumor-to-brain ratio was highest in glioblastoma patients (4.18) followed by patients with IDH wild-type grade II and III glioma (3.41). The latter TBRmax values were higher compared with those in patients with IDH-mutant grade II/III glioma without 1p/19q codeletion (1.95) and in patients with IDH-mutant 1p/19q codeleted grade II and III glioma (2.79). Magnetic resonance spectroscopy marker distribution showed no clear trend. Receiver operating characteristic analysis revealed TBRmax to be the best performing parameter in identifying IDH status (area under the curve, 0.67) and all spectroscopy markers combined in identifying glioma subgroups (area under the curve, 0.68), respectively.
L-Methyl-11C-methionine PET and MRS bear limited potential in glioma subgrouping. L-Methyl-11C-methionine PET appears to be superior in differentiating IDH status, whereas MRS is more helpful in glioma subgrouping.
From the *Division of Clinical Neurooncology, Department of Neurology, University Hospital Essen, University Duisburg-Essen;
†DKFZ-Division Translational Neurooncology at the West German Cancer Center (WTZ), University Hospital Essen, and German Cancer Consortium (DKTK), Partner Site University Hospital Essen;
‡West German Cancer Center (WTZ), University Hospital Essen, University Duisburg-Essen, and German Cancer Consortium, Partner Site University Hospital Essen;
§Department of Nuclear Medicine,
∥Institute of Diagnostic and Interventional Radiology and Neuroradiology,
¶Institute of Neuropathology,
Departments of **Neurosurgery, and
††Radiotherapy, University Hospital Essen, University Duisburg-Essen, Essen;
‡‡Department of Diagnostic and Interventional Radiology, Medical Faculty, University Düsseldorf, Düsseldorf;
§§Department of Neurology, University Hospital Essen, University Duisburg-Essen, Essen, Germany;
∥∥Department of Radiology, University of Southern California. Los Angeles, CA; and
¶¶Nuclear Medicine Unit, Department of Imaging and Clinical Pathology, Rovigo, Italy.
Received for publication January 29, 2019; revision accepted February 21, 2019.
S.K., L.L., K.H., and M.G. contributed equally.
Conflicts of interest and sources of funding: none declared.
Correspondence to: Martin Glas, MD, Division of Clinical Neurooncology, Department of Neurology, University Hospital Essen, University Duisburg-Essen, D-45147 Essen, Germany. E-mail: Martin.Glas@uk-essen.de.