Biopsy targeting gliomas: do functional imaging techniques identify similar target areas?

Area of Science:

• Neuro-oncology
• Medical Imaging
• Radiology

Background:

• Glioma heterogeneity necessitates targeted biopsies of the most anaplastic regions.
• Functional imaging techniques like MRI and PET are used to identify these critical areas.
• The concordance between different functional imaging modalities for biopsy targeting remains unclear.

Purpose of the Study:

• To evaluate if various functional imaging modalities identify similar target areas in suspected gliomas.
• To assess the agreement between different MRI and PET techniques in pinpointing the most anaplastic tumor regions.

Main Methods:

• Sixty-one patients with suspected glioma underwent MRI, 18F-fluorothymidine-PET, and 18F-fluorodeoxyglucose-PET.
• MRI protocols included sodium (23Na)-MRI, proton spectroscopic imaging (1H-MRSI), arterial spin-labeling (ASL), dynamic contrast-enhanced (DCE)-MRI, and dynamic susceptibility-weighted (DSC)-MRI.
• Apparent diffusion coefficient (ADC) maps were generated, and image analysis focused on colocalization of conspicuous tumor areas indicating proliferation and microcirculation.

Main Results:

• Higher glioma grade correlated with increased tumor vascularity and proliferation parameters, and decreased ADC values.
• Except for 23Na-MRI, most modalities showed good to perfect agreement (>80%) in identifying tumor areas with increased thymidine uptake, highest choline, and elevated microcirculation.
• 18F-fluorothymidine-PET, DSC-MRI, DCE-MRI, diffusion-weighted imaging, and MR spectroscopic imaging detected heterogeneity in high-grade gliomas but not in low-grade gliomas.

Conclusions:

• Functional imaging techniques assessing microcirculation and proliferation identify similar target areas in gliomas.
• This concordance supports the use of these multimodal imaging approaches for precise glioma biopsy targeting.