Tumour enhancing fraction (EnF) in glioma: relationship to tumour grade

Abstract

The aim of this research was to determine whether the proportion of a tumour that enhances (enhancing fraction, EnF) and changes in EnF with enhancement threshold differ between low and high grade glioma. Forty-four patients (45 gliomas comprising 16 grade II, 5 grade III and 24 grade IV) were studied. Imaging included pre-and post-contrast-enhanced T 1 -weighted sequences and T 1 -weighted DCE-MRI. Thresholded enhancement maps were generated for each tumour by using a range of values of the initial area under the contrast concentration curve (IAUC).

Enhancing Fraction in Glioma and Its Relationship to the Tumoral Vascular Microenvironment: A Dynamic Contrast-Enhanced MR Imaging Study

“…In a previous study, we have demonstrated that EnF defined at a threshold of IAUC 60 Ͼ 2.5 mmol.s pro-vides optimal discrimination between low-and high-grade gliomas. 29 The value of EnF in an individual tumor will be affected by a number of variations in the tumor vascular microenvironment. Areas of necrosis or nonperfusion will clearly fail to enhance, but enhancement may also not occur in viable tumor if perfusion pressure and perfusion rates are low relative to the vascular half-life of the contrast media.…”

Survival and Enhancing Fraction (enf) in Glioblastoma Multiforme (GBM)

“…A number of patients with cerebral tumours will have a CT scan as their initial investigation, but the imaging modality of choice for brain tumour characterisation is an MRI scan and therefore the ability to derive a signal intensity based MRI measure of EnF was assessed in the current study as opposed to a CT based measure. A study of DCE-MRI derived EnF in glioma has shown the use of thresholding allows the distinction between histological grade of tumour [3]. In the unthresholded form, EnF IAUC60>0 correlated with v p in low grade tumours and K trans in GBM [2].…”

“…EnF is a relatively recently described parameter [2,3,20,21]. A CT variant of this measure has shown potential in predicting disease free survival and time to progression in patients with ovarian carcinoma [1].…”

“…The commonest approach to calculating EnF from MRI is to use the initial area under the concentration time curve (IAUC 60 ) derived from dynamic contrast enhanced MRI (DCE-MRI) and to measure the proportion of voxels within a tumour with a measurable IAUC (> 0 mMol.s) [2,3]. The application of a thresholding technique to EnF allows for the distinction between low and high grade glioma [3]. EnF has been shown to correlate with the established DCE-MRI derived parameters v p (in low grade glioma) and K trans (in glioblastoma multiforme, GBM) [2].…”

“…An MRI based measure of EnF has been shown to provide clinical information in glioma [2,3]. The commonest approach to calculating EnF from MRI is to use the initial area under the concentration time curve (IAUC 60 ) derived from dynamic contrast enhanced MRI (DCE-MRI) and to measure the proportion of voxels within a tumour with a measurable IAUC (> 0 mMol.s) [2,3]. The application of a thresholding technique to EnF allows for the distinction between low and high grade glioma [3].…”