Combining Perfusion and High B-value Diffusion MRI to Inform Prognosis and Predict Failure Patterns in Glioblastoma

Publication date: Available online 2 June 2018
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Daniel R. Wahl, Michelle M. Kim, Madhava P. Aryal, Holly Hartman, Theodore S. Lawrence, Matthew J. Schipper, Hemant A. Parmar, Yue Cao
BackgroundAdvanced imaging modalities such as high b-value diffusion and dynamic contrast enhancement (DCE) MRI have the potential to improve the clinical management of glioblastoma by informing prognosis, predicting sites of progression and guiding dose-escalated radiation to maximize tumor control while minimizing toxicity.MethodsFifty-two patients with de novo GBM underwent MRI scanning prior to chemoradiation. Enhanced tumor volumes excluding surgical cavity (TVGdNoCavity), hypercellularity (TVHCV) and increased cerebral blood volume (TVCBV) were defined using conventional post-gadolinium T1 images, high b-value (3000 s/mm²) diffusion-weighted images and CBV maps from T1-weighted DCE images, respectively. The image-phenotype TVs were analyzed for prediction of progression-free survival (PSF) (Cox proportional hazard models), and sites of progression (TVPOF).ResultsThe median PFS of the cohort was 13 months. TVCBV and TVHCV were spatially distinct with a mean overlap of only 21%. Univariate analysis showed that increasing age, decreasing radiation dose, larger TVHCV and larger overlap of TVHCV and TVCBV (TVoverlap) were significantly associated with inferior PFS, while multivariate analysis identified that TVHCV was the most adversely prognostic imaging-defined variable. TVGdNoCavity as well as the union of TVHCV and TVCBV had a high likelihood of containing the TVPOF, while the volume comprised of the intersection of TVHCV and TVCBV had an especially high likelihood of progressing.ConclusionsTVHCV and TVoverlap are prognostic for PFS. Combinations of TVGd, TVCBV and TVHCV could predict tumor progression locations better than individual subvolumes. Radiation dose escalation to these subvolumes could be a promising therapeutic strategy.



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