Prognostic stratification of newly diagnosed <i>IDH-</i> mutant gliomas by [18F]fluoroethyltyrosine and [11C]methionine PET: A retrospective, bicentric cohort study
Maximilian J. Mair, Jan‐Michael Werner, Jonathan Weller, Enio Barci, Sophie Katzendobler, Jera Isakaj, Luzia Berchtold, Tülin Aras, Roman Stürzl, Juliane Hennenberg, Jonas Reis, Hannah Christina Puhr, Thomas Schabhüttl, Barbara Kiesel, Georg Widhalm, Adelheid Wöehrer, Thomas Nakuz, Marcus Hacker, Julia Furtner, Stephan Schönecker, Patrick N. Harter, Louisa von Baumgarten, Anna S Berghoff, Niklas Thon, Matthias Preusser, Nathalie L. Albert
Abstract
BACKGROUND: Improved prognostic stratification, including imaging-based parameters, is needed to guide treatment decisions in IDH-mutant glioma. METHODS: In this bicentric retrospective study, 457 patients with IDH-mutant glioma and [18F]fluoroethyltyrosine or [11C]methionine positron emission tomography (PET) prior to radiotherapy or systemic treatment were included. Associations of maximum and mean tumor-to-background ratios (TBRmax/TBRmean) and PET-positive volume (PET volume) with time to next intervention (TTNI) and overall survival (OS) were analyzed. RESULTS: Overall, 251 (54.9%) patients with astrocytoma and 206 (45.1%) with oligodendroglioma were included. In patients with astrocytoma who underwent PET before resection, measurable disease according to PET RANO 1.0 criteria was associated with shorter TTNI compared to no/non-measurable disease (median 46.0 vs. 67.9 months; P = .004). Univariable analysis showed an association of TTNI with TBRmax, TBRmean, and PET volume in astrocytoma and PET volume in oligodendroglioma. Multivariable analyses including age, WHO grade, extent of resection, postoperative treatment, and magnetic resonance imaging (MRI)-based tumor extent indicated an association of TTNI with TBRmax (HR 1.48 [95%CI: 1.09-2.01]) and TBRmean (HR 1.93 [95%CI: 1.14-3.27]) in astrocytoma and PET volume (HR [10 ml increase]: 1.18 [95%CI: 1.03-1.36]) in oligodendroglioma. In astrocytoma, also OS was related to TBRmax (HR: 1.40 [95%CI: 1.13-1.74]), TBRmean (HR: 1.97 [95%CI: 1.21-3.22]), and PET volume (HR: 1.23 [95%CI: 1.10-1.37]) in univariable analysis. Further analyses considering timepoint of PET showed consistent results. CONCLUSIONS: In this retrospective study, amino acid PET parameters were associated with outcome in newly diagnosed IDH-mutant glioma. Future clinical trials should include PET imaging to define imaging-based prognostic signatures.