Paired [18F]FDOPA and [18F]FDG PET Shows Complementary Prognostic Associations at Recurrence in IDH-Wildtype Glioblastoma

Background/Objectives: Prognostic PET biomarkers in glioblastoma remain mostly as a single tracer and poorly characterized at recurrence. We investigated whether paired [18F]FDOPA/[18F]FDG PET captures complementary metabolic information associated with survival in IDH-wildtype glioblastoma.

Methods

Sixty-five consecutive patients underwent paired [18F]FDOPA/[18F]FDG PET/MR at baseline and/or recurrence. Survival was analyzed from baseline PET/MR (OS1, n = 36) and recurrence PET/MR (OS2, n = 55); longitudinal analyses used the paired subgroup (n = 26). FDOPA and FDG tumor masks were independently segmented within a FLAIR-derived tumor box, and metrics were extracted from tracer-specific masks, their intersection, and their union. Metrics significant in Kaplan–Meier or univariable Cox analyses were tested in adjusted Cox models. Benjamini–Hochberg false discovery rate correction was used as a sensitivity analysis for the continuous Cox screening tests.