Combined 68Ga-NOTA-PRGD2 and 18F-FDG PET/CT Can Discriminate Uncommon Meningioma Mimicking High-Grade Glioma.

OBJECTIVES

Uncommon pathological subtypes of meningioma may present with severe peritumoral brain edema and mimic high-grade glioma (HGG). In a prospective cohort study of Ga-NOTA-PRGD2 PET/CT to evaluate glioma, we occasionally observed that a combination of Ga-NOTA-PRGD2 and F-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 Ga-NOTA-PRGD2 PET/CT. Brain F-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 Ga-NOTA-PRGD2 uptake with higher SUVmax on Ga-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 Ga-NOTA-PRGD2 over F-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 Ga-NOTA-PRGD2 PET (P < 0.05).

CONCLUSIONS

This study reveals a specific imaging pattern of uncommon meningioma mimicking HGG, in which Ga-NOTA-PRGD2 PET provided added value to F-FDG PET.