Work

Advanced imaging characterization of post-chemoradiation glioblastoma stratified by diffusion MRI phenotypes known to predict favorable anti-VEGF response

Year: 2025

Type: article

Abstract: Purpose Recurrent glioblastomas showing a survival benefit from anti-VEGF agents are known to exhibit a distinct diffusion MRI phenotype. We aim to characterize advanced imaging features of this glioblastoma subset. Methods MRI scans from 87 patients with IDH-wildtype glioblastoma were analyzed. All patients had completed standard chemoradiation and were anti-VEGF-naïve. Contrast-enhancing tumor segmentations were used to extract: the lowest peak of the double gaussian distribution of apparent diffusion coefficient values (ADC L ) calculated from diffusion MRI, relative cerebral blood flow (rCBV) values from perfusion MRI, MTR asym @ 3ppm from pH-weighted amine CEST MRI, quantitative T 2 and T 2 * relaxation times (qT 2 and qT 2 *), T 1 w subtraction map values, and contrast-enhancing tumor volume. Lesions were categorized as high- or low-ADC L using a cutoff of 1240 µm 2 /s, according to previous studies. Results High-ADC L lesions showed significantly lower rCBV (1.02 vs. 1.28, p = 0.0057), higher MTR asym @ 3ppm (2.36% vs. 2.10%, p = 0.0043), and higher qT 2 (114.8 ms vs. 100.9 ms, p = 0.0094), compared to low-ADC L lesions. No group differences were seen in contrast-enhancing tumor volume, T 1 w subtraction map values, and qT 2 *, nor in clinical variables such as sex category, MGMT status, and EGFR status. Finally, no clear group-specific preferential locations were seen. Conclusion Post-chemoradiation glioblastomas with a diffusion MRI phenotype that is known to predict a favorable response to anti-VEGF (ADC L ≥1240 µm 2 /s) have distinct biological features, with different perfusion and metabolic characteristics, and T 2 relaxation times.

Source: Journal of Neuro-Oncology

DOI: 10.1007/s11060-025-05019-8