MR imaging biomarkers in neuro-oncology

The central role of magnetic resonance imaging (MRI) in neuro-oncology is undisputed, to diagnose and monitor disease activity, provide treatment decision support and guide focused treatments, and to determine response to treatment both in clinical practice and in clinical trials. Despite recent substantial advances in imaging technology and image analysis techniques, clinical MRI is still primarily applied on the basis of qualitative, subjective interpretation of macrostructural features rather than quantitatively and with taking pathophysiological features into account.
The field of quantitative imaging and imaging biomarker development is however maturing. The European Imaging Biomarker ALLiance (EIBALL) and Quantitative Imaging Biomarker Alliance (QIBA) are important drivers setting standards for development, validation and implementation, and promoting the use of quantitative imaging and imaging biomarkers by demonstrating their clinical value. In parallel advanced imaging techniques are reaching the clinical arena, providing quantitative, commonly physiological parameters that further drive the discovery, validation, and implementation of quantitative imaging and imaging biomarkers in the clinical routine. Additionally, computational analysis techniques convert medical images into objective high-dimensional data to define radiomic signatures of disease states.
This review addresses the definition and current state of MRI biomarkers, as well as quantitative image analysis techniques with clinical potential for neuro-oncology.