Background: The heterogeneous nature of glioma makes it difficult to select a target for stereotactic biopsy that will be representative of grade severity on non-contrast-enhanced lesion imaging. The objective of this study was to evaluate the benefit of fusion of metabolic images (PET 18F-DOPA) with magnetic resonance imaging (MRI) morphological images for cerebral biopsy under stereotactic conditions of glioma without contrast enhancement.
Patients and methods: This single-center prospective observational study conducted between January 2016 and April 2018 included 20 consecutive patients (mean age: 45±19.5 years; range, 9-80 years) who underwent cerebral biopsy for a tumor without MRI enhancement but with hypermetabolism on 18F-FDOPA PET (positron emission tomography). Standard 18F-FDOPA uptake value (SUVmax) was determined for diagnosis of high-grade glioma, with comparison to histomolecular results.
Results: Histological diagnosis was made in all patients (100%). Samples from hypermetabolism areas revealed high-grade glial tumor in 16 patients (80%). For a SUVmax threshold of 1.75, sensitivity was 81.2%, specificity 50%, PPV 86.7% and VPN 40% for diagnosis of high-grade glioma. No significant association between SUVmax and histomolecular mutation was found.
Conclusion: 18F-FDOPA metabolic imaging is an aid in choosing the target to be biopsied under stereotactic conditions in tumors without MR enhancement. Nevertheless, despite good sensitivity, 18F-FDOPA PET is insufficient for definitive diagnosis of high-grade tumor.
Keywords: (18)F-FDOPA PET; Biopsy target; Brain tumor; Glioma target; PET-MRI image registration.
Copyright © 2019 Elsevier Masson SAS. All rights reserved.