Comparing methods of biomarker quantification for contrast clearance analysis in patients with brain metastases

Motivation: Differentiating tumour progression and treatment-induced changes in brain metastases is challenging, and quantitative measures of tumour burden and response are needed. Goal(s): To develop and compare quantitative contrast clearance analysis (CCA) mapping techniques with conventional qualitative approaches in 9 patients with brain metastases. Approach: We assessed the correlation of Relative Enhancement and Fractional Enhancement methods with conventional CCA in the brain and within detected tumour regions. Results: Fractional Enhancement mapping was superior to relative enhancement in terms of its statistical properties and correlation with conventional CCA. Impact: Quantitative enhancement fraction mapping of contrast clearance analysis (CCA) data is clinically feasible and demonstrates good correlation with conventional CCA. When used in combination with conventional radiological CCA, it may help quantify post-treatment changes in brain metastases following treatment.