Imaging biomarkers from multiparametric magnetic resonance imaging are associated with survival outcomes in patients with brain metastases from breast cancer

Objectives The aim of this study is to investigate the correlation of survival outcomes with imaging biomarkers from multiparametric magnetic resonance imaging (MRI) in patients with brain metastases from breast cancer (BMBC). Methods This study was approved by the institutional review board. Twenty-two patients with BMBC who underwent treatment involving bevacizumab on day 1, etoposide on days 2-4, and cisplatin on day 2 in 21-day cycles were prospectively enrolled for a phase II study. Three brain MRIs were performed: before the treatment, on day 1, and on day 21. Eight imaging biomarkers were derived from dynamic contrast-enhanced MRI (Peak, IAUC(60), K-trans, k(ep), v(e)), diffusion-weighted imaging [apparent diffusion coefficient (ADC)], and MR spectroscopy (choline/N-acetylaspartate and choline/creatine ratios). The relative changes (Delta) in these biomarkers were correlated with the central nervous system (CNS)-specific progression-free survival (PFS) and overall survival (OS) using the Kaplan-Meier and Cox proportional hazard models. Results There were no significant differences in the survival outcomes as per the changes in the biomarkers on day 1. On day 21, those with a low Delta K-trans (p = 0.024) or Delta ADC (p = 0.053) reduction had shorter CNS-specific PFS; further, those with a low Delta Peak (p = 0.012) or Delta IAUC(60) (p = 0.04) reduction had shorter OS compared with those with high reductions. In multivariate analyses, Delta K-trans and Peak were independent prognostic factors for CNS-specific PFS and OS, respectively, after controlling for age, size, hormone receptors, and performance status. Conclusions Multiparametric MRI may help predict the survival outcomes in patients with BMBC.