Combination of magnetic resonance spectroscopy and11c-methionine positron emission tomography for the accurate diagnosis of non-enhancing supratentorial glioma

Abstract

Objective: To evaluate whether the combination of magnetic resonance spectroscopy (MRS) and11C-methionine positron emission tomography (11C-MET PET) could increase accurate diagnostic sensitivity for non-enhancing supratentorial gliomas. Materials and Methods: Between February 2012 and December 2017, 109 patients with non-enhanced supratentorial lesions on contrast-enhanced MRI were enrolled. Each patient underwent MRS and11C-MET PET before treatment. A lesion was considered to be a glioma when either the MRS or11C-MET PET results reached the diagnostic threshold. The radiological diagnosis was compared with the pathological diagnosis or medical diagnostic criteria. Results: The sensitivity and specificity were 60.0% and 50.0% for MRS and 75.8% and 50.0% for11C-MET PET, respectively. Upon combining the two modalities, the sensitivity and specificity of the imaging-based diagnosis prior to surgery reached 89.5% and 42.9%, respectively. Statistically significant differences in the sensitivities were observed between the combined and individual approaches (MRS alone, 89.5% vs. 60.0%, p < 0.001;11C-MET PET alone, 89.5% vs. 75.8%, p = 0.001). However, no significant differences in specificity were observed between the combined and individual modalities. Conclusion: The combination of MRS and11C-MET PET findings significantly increases accurate diagnostic sensitivity for non-enhancing supratentorial gliomas without significantly lowering the specificity. This finding suggests the potential of the combined MRS and11C-MET PET approach in clinical applications.