PET-based response assessment criteria for diffuse gliomas (PET RANO 1.0): methodological application in [¹⁸F]-FDOPA...

Area of Science:

• Neuro-oncology
• Radiology
• Nuclear Medicine

Background:

• The Response Assessment in Neuro-Oncology (RANO) group established PET-based criteria for diffuse gliomas (PET RANO 1.0).
• Evaluation of these criteria using the amino acid [18F]-FDOPA radiotracer is crucial for accurate glioma assessment.
• Retrospective analysis of glioma patients with baseline [18F]-FDOPA PET scans was performed.

Purpose of the Study:

• To assess the methodological application of PET RANO 1.0 criteria with [18F]-FDOPA PET.
• To compare PET RANO 1.0 criteria against expert interpretation for glioma response assessment.
• To identify the contribution of individual PET parameters within the PET RANO 1.0 criteria.

Main Methods:

• Retrospective inclusion of 90 glioma patients with at least one baseline [18F]-FDOPA PET scan.
• Application of PET RANO 1.0 criteria to 65 patients with follow-up scans, compared to expert interpretation.
• Separate evaluation of PET parameters (metabolic tumor volume, striatum infiltration, etc.) for their contribution to response definition.

Main Results:

• 80% concordance between PET RANO 1.0 criteria and expert interpretation in 65 patients, consistent across newly diagnosed/recurrent and IDH-mutant/wildtype gliomas.
• Metabolic tumor volume was the most contributive parameter (71% of cases) for response definition.
• Discordances were linked to striatum infiltration, post-treatment effects, measurable disease criteria, and thresholds.

Conclusions:

• The PET RANO 1.0 criteria are applicable to [18F]-FDOPA PET imaging in gliomas.
• A reasonable concordance exists between PET RANO 1.0 criteria and expert interpretation.
• Analyzing discordant cases will inform future updates to the PET RANO 1.0 criteria.