Improved Detection of Transosseous Meningiomas Using ⁶⁸Ga-DOTATATE PET/CT Compared with Contrast-Enhanced MRI

⁶⁸Ga-DOTATATE PET/CT enables detection of meningioma tissue based on somatostatin receptor 2 expression. Transosseous extension of intracranial meningiomas is known to be an important risk factor for tumor recurrence and patient mortality. We analyzed the diagnostic performance of ⁶⁸Ga-DOTATATE PET/CT and contrast-enhanced MRI (CE-MRI) for the detection of osseous infiltration using qualitative and quantitative imaging parameters. Methods: In this institutional review board-approved retrospective study, subjects were selected from 327 consecutive ⁶⁸Ga-DOTATATE PET/CT examinations for evaluation of confirmed or suspected meningioma. Inclusion criteria were CE-MRI within 30 d and pathology-confirmed meningioma diagnosis with inclusion or exclusion of transosseous extension as the standard of reference. Imaging was analyzed by two readers. Tracer uptake values and meningioma volumes were determined. χ², Mann-Whitney U, Wilcoxon signed rank, and McNemar tests, as well as receiver-operating-characteristic analyses, were performed to compare variables and diagnostic performance. Results: Eighty-two patients fulfilled the inclusion criteria. Patients with transosseous extension of meningioma (n = 67) showed significantly larger lesions (median, 12.8 vs. 3.3 mL; P < 0.001) and significantly higher tracer uptake values (median SUV_max, 14.2 vs. 7.6; P = 0.011) than patients with extraosseous meningiomas (n = 15). ⁶⁸Ga-DOTATATE PET/CT in comparison to CE-MRI performed at a higher sensitivity (98.5% vs. 53.7%) while maintaining high specificity (86.7% vs. 93.3%) in the detection of osseous involvement (P < 0.001). In receiver-operating-characteristic analysis, PET/CT assessment performed better than CE-MRI (area under the curve, 0.932 vs. 0.773). PET/CT- and CE-MRI-based volume estimation yielded comparable results for extraosseous meningiomas (P = 0.132) and the extraosseous part of transosseous meningiomas (P = 0.636), whereas the volume of the intraosseous part was assessed as significantly larger by PET/CT (P < 0.001). Conclusion:⁶⁸Ga-DOTATATE PET/CT enables improved detection of the transosseous extension of intracranial meningiomas compared with CE-MRI.