Abstract
BACKGROUND AND PURPOSE: Perfusion MR imaging measures of relative CBV can distinguish recurrent tumor from posttreatment radiation effects in high-grade gliomas. Currently, relative CBV measurement requires normalization based on user-defined reference tissues. A recently proposed method of relative CBV standardization eliminates the need for user input. This study compares the predictive performance of relative CBV standardization against relative CBV normalization for quantifying recurrent tumor burden in high-grade gliomas relative to posttreatment radiation effects.
MATERIALS AND METHODS: We recruited 38 previously treated patients with high-grade gliomas (World Health Organization grades III or IV) undergoing surgical re-resection for new contrast-enhancing lesions concerning for recurrent tumor versus posttreatment radiation effects. We recovered 112 image-localized biopsies and quantified the percentage of histologic tumor content versus posttreatment radiation effects for each sample. We measured spatially matched normalized and standardized relative CBV metrics (mean, median) and fractional tumor burden for each biopsy. We compared relative CBV performance to predict tumor content, including the Pearson correlation (r), against histologic tumor content (0%–100%) and the receiver operating characteristic area under the curve for predicting high-versus-low tumor content using binary histologic cutoffs (≥50%; ≥80% tumor).
RESULTS: Across relative CBV metrics, fractional tumor burden showed the highest correlations with tumor content (0%–100%) for normalized (r = 0.63, P < .001) and standardized (r = 0.66, P < .001) values. With binary cutoffs (ie, ≥50%; ≥80% tumor), predictive accuracies were similar for both standardized and normalized metrics and across relative CBV metrics. Median relative CBV achieved the highest area under the curve (normalized = 0.87, standardized = 0.86) for predicting ≥50% tumor, while fractional tumor burden achieved the highest area under the curve (normalized = 0.77, standardized = 0.80) for predicting ≥80% tumor.
CONCLUSIONS: Standardization of relative CBV achieves similar performance compared with normalized relative CBV and offers an important step toward workflow optimization and consensus methodology.
ABBREVIATIONS:
- AUC
- area under the curve
- FTB
- fractional tumor burden
- GBM
- glioblastoma multiforme
- NAWM
- normal-appearing white matter
- PTRE
- posttreatment radiation effects
- rCBV
- relative CBV
- ROC
- receiver operating characteristic
Footnotes
This work was supported by grants NS082609 (NIH), CA221938 (NIH), CA220378 (NIH), CA158079 (NIH), Mayo Clinic Foundation, James S. McDonnell Foundation, Ben and Catherine Ivy Foundation, and the Arizona Biomedical Research Commission (ABRC).
Disclosures: Kris A. Smith—UNRELATED: Payment for Lectures Including Service on Speakers Bureaus: Metabolic Health; Patents (Planned, Pending or Issued): OsteoMed. Richard S. Zimmerman—UNRELATED: Consultancy: NeuroPage, Medtronic. Leslie C. Baxter—RELATED: Grant: National Cancer Institute, Comments: My institution received funding as part of the grant under which this work was performed*; UNRELATED: Employment: Barrow Neurological Institute. Kristin R. Swanson—RELATED: Grant: NS082609, CA221938, CA220378, Mayo Clinic Foundation, James S. McDonnell Foundation, Ivy Foundation, Arizona Biomedical Research Commission*; UNRELATED: Board Membership: James S McDonnell Foundation Scientific Board; Payment for Development of Educational Presentations: multiple patents and applications but no funds. Christopher C. Quarles—RELATED: Grant: National Institutes of Health.* Kathleen M. Schmainda—RELATED: Grant: National Institutes of Health*; UNRELATED: Stock/Stock Options: IQ-AI Ltd, Comments: ownership interest; Other: Imaging Biometrics LLC, Comments: spouse’s salary. Leland S. Hu—RELATED: Grant: U01 CA220378, R01 CA221938, R21 NS082609, Mayo Clinic Foundation, Arizona Biomedical Research Commission*; UNRELATED: Patents (Planned, Pending or Issued): multiple patents but no money paid. *Money paid to the institution.
- © 2020 by American Journal of Neuroradiology
Indicates open access to non-subscribers at www.ajnr.org