Uncommon pathological subtypes of meningioma may present with severe peritumoral brain edema and mimic high-grade glioma (HGG). In a prospective cohort study of 68Ga-NOTA-PRGD2 PET/CT to evaluate glioma, we occasionally observed that a combination of 68Ga-NOTA-PRGD2 and 18F-FDG was able to differentiate these 2 lesion types.Methods
From 2013 to 2016, 21 patients suspected of HGG by MRI were recruited for evaluation using 68Ga-NOTA-PRGD2 PET/CT. Brain 18F-FDG PET/CT was performed within 3 days for comparison, and the tumor was surgically removed. The PET results were compared with integrin αvβ3 expression and microvascular density quantification of tumor samples.Results
Of the 21 recruited patients, 5 patients were finally pathologically diagnosed as uncommon meningioma with severe peritumoral brain edema, including chordoid meningioma (n = 1), angiomatous meningioma (n = 1), and mixed angiomatous and microcystic meningioma (n = 3). Sixteen were diagnosed as HGG. All the meningioma lesions (n = 5) exhibited intense and homogeneous 68Ga-NOTA-PRGD2 uptake with higher SUVmax on 68Ga-NOTA-PRGD2 PET (1.64–7.86; mean ± SD, 4.23 ± 2.48) than the HGG lesions (0.81–2.99; mean ± SD, 1.57 ± 0.33; P = 0.0047). Moreover, the uptake ratios of 68Ga-NOTA-PRGD2 over 18F-FDG, normalized as lg100 * SUVmax (RGD / FDG), in the uncommon meningiomas were significantly higher than those in HGG (1.87 ± 1.36 vs 1.04 ± 0.87, P = 0.0001). A cutoff value of 1.58 was able to discriminate between these lesion types. There were positive correlations among the expression level of integrin αvβ3, microvascular density, and the tumor-to-background ratio derived from 68Ga-NOTA-PRGD2 PET (P < 0.05).Conclusions
This study reveals a specific imaging pattern of uncommon meningioma mimicking HGG, in which 68Ga-NOTA-PRGD2 PET provided added value to 18F-FDG PET.