A new diagnostic marker for differentiating multicentric gliomas from multiple intracranial diffuse large B-cell lymphomas on 18F-FDG PET images

Abstract

Intracranial gliomas and lymphomas may share similar radiological manifestations, while the treatment strategies for them are different. The aim of the study was to investigate the diagnostic value of fluorine-18-fluoro-2-deoxy-D-glucose (F-FDG) positron emission computed tomography (PET) for differentiation of multicentric gliomas and intracranial multiple diffuse large B-cell lymphomas (DLBCLs) as a study of diagnostic accuracy.A total of 32 patients with multiple intracranial tumors visualized on contrast-enhanced magnetic resonance imaging (MRI) were retrospectively evaluated. Histopathological findings confirmed multicentric gliomas and multiple DLBCLs in 17 and 15 patients, respectively. All patients underwent F-FDG PET with or without C-methionine PET. Maximum standardized uptake values (SUVmax) and tumor-to-normal tissue (T/N) ratios were compared between the 2 tumors. The diagnostic value of F-FDG PET for differentiating multicentric gliomas from multiple DLBCLs was evaluated by receiver operating characteristic (ROC) analysis.The SUVmax of multiple DLBCLs was significantly higher than that of multicentric gliomas (P = .009). However, the percentage of maximum difference-value of SUVmax (or T/N ratio) of multiple DLBCLs was significant lower than that of multicentric gliomas (P < .001). The ROC curve demonstrated that the percentage of maximum difference-value of SUVmax (or T/N ratio) on F-FDG PET images could effectively differentiate multicentric gliomas from multiple DLBCLs, with a cut-off value of 44.4%, sensitivity of 64.7%, and specificity of 100% (P < .001).Percentage of maximum difference-value of SUVmax (or T/N ratio) on F-FDG PET images might be a potential indicator for distinguishing multicentric gliomas from intracranial multiple DLBCLs, which might help determine the treatment strategy.

Figure 1

Multicentric gliomas. A lesion (white arrow) located at the junction of the right frontal and parietal lobes exhibited higher metabolism on ¹⁸F-FDG PET findings than normal gray matter. The lesion exhibited hyperintensity on T2-weighted MR images and obvious inhomogeneous contrast enhancement and restricted diffusion on diffusion-weighted MR images (upper row). Another lesion in the mid-brain (black arrow) exhibited much lower metabolism than the above lesion on ¹⁸F-FDG PET findings and similar manifestation on MR images (lower row).

Figure 2

Multiple diffuse large B-cell lymphomas. Two lesions in the right frontal lobe and basal ganglion exhibited much higher accumulation of ¹⁸F-FDG on PET images than normal gray matter. They exhibited iso to hyperintensities with edema on T2-weighted MR images, strong and relatively homogeneous enhancement on contrast-enhanced T1-weighted MR images, and slightly restricted diffusion on diffusion-weighted MR images.

Figure 3

Receiver operating characteristic curves of different diagnostic markers for differentiating multicentric gliomas from multiple diffuse large B-cell lymphomas. In comparison with the other 4 diagnostic parameters, percentage of maximum difference-value of maximum standardized uptake value (or tumor to normal ratio) could better distinguish multicentric gliomas from diffuse large B-cell lymphomas (sensitivity and specificity, 64.7% and 100%, respectively).