Post-treatment changes of tumour perfusion parameters can help to predict survival in patients with high-grade astrocytoma.

Objectives: Vascular characteristics of tumour and peritumoral volumes of high-grade gliomas change with treatment. This work evaluates the variations of T2*-weighted perfusion parameters as overall survival (OS) predictors.
Methods: Forty-five patients with histologically confirmed high-grade astrocytoma (8 grade III and 37 grade IV) were included. All patients underwent pre- and post-treatment T2*-weighted contrast-enhanced magnetic resonance (MR) imaging. Tumour, peritumoral and control volumes were segmented. Relative variations of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), K ^trans-T2* , k _ep-T2* , v _e-T2* and v _p-T2* were calculated. Differences regarding tumour grade and surgical resection extension were evaluated with ANOVA tests. For each parameter, two groups were defined by non-supervised clusterisation. Survival analysis were performed on these groups.
Results: For the tumour region, the 90th percentile increase or stagnation of CBV was associated with shorter survival, while a decrease related to longer survival (393 ± 189 vs 594 ± 294 days; log-rank p = 0.019; Cox hazard-ratio, 2.31; 95% confidence interval [CI], 1.12-4.74). K ^trans-T2* showed similar results (414 ± 177 vs 553 ± 312 days; log-rank p = 0.037; hazard-ratio, 2.19; 95% CI, 1.03-4.65). The peritumoral area values showed no relationship with OS.
Conclusions: Post-treatment variations of the highest CBV and K ^trans-T2* values in the tumour volume are predictive factors of OS in patients with high-grade gliomas.
Key Points: • Vascular characteristics of high-grade glioma tumour and peritumoral regions change with treatment. • Quantitative assessment of MRI perfusion provides valuable information regarding tumour aggressiveness. • Quantitative T2*-weighted perfusion parameters can help to predict overall survival. • Post-treatment variations of CBV and K ^trans-T2 values are predictive factors of OS. • Increased values may justify treatment intensification in these patients.