The predictive value of quantitative DCE metrics for immediate therapeutic response of high-intensity focused ultrasound ablation (HIFU) of symptomatic uterine fibroids.

Abstract

The aim of this study was to investigate the value of quantitative DCE-MRI parameters for predicting the immediate non-perfused volume ratio (NPVR) of HIFU therapy in the treatment of symptomatic uterine fibroids. A total of 78 symptomatic uterine fibroids in 65 female patients were treated with US-HIFU therapy. All patients underwent conventional MRI and DCE-MRI scans 1day before and 3days after HIFU treatment. Permeability parameters K trans, K ep, V e, and V p and T1 perfusion parameters BF and BV of pretreatment were measured as a baseline, while NPVR was used to assess immediate ablation efficiency. Data were assigned to NPVR ≧70% and NPVR <70% groups. Then, the predictive performances of different parameters for ablation efficacy were studied to seek the optimal cut-off value, and the length of time to calculate the variable parameters in each case was recorded. (1) It was observed that the pretreatment K trans, K ep, V e, and BF values of the NPVR ≧70% group were significantly lower compared to the NPVR <70% group (p<0.05). (2) The immediate NPVR was negatively correlated with the K trans, BF, and BV values before HIFU treatment (r=-0.561, -0.712, and -0.528, respectively, p<0.05 for all). (3) The AUCs of pretreatment K trans, BF, BV values, and K trans combined with BF used to predict the immediate NPVR were 0.810, 0.909, 0.795, and 0.922, respectively (p<0.05 for all). (4) The mean time to calculate the variable parameters in each case was 7.5min. Higher K trans, BF, and BV values at baseline DCE-MRI suggested a poor ablation efficacy of HIFU therapy for symptomatic uterine fibroids, while the pretreatment DCE-MRI parameters could be useful biomarkers for predicting the ablation efficacy in select cases. The software used to calculate DCE-MRI parameters wassimpler,quicker,and easier to incorporate into clinical practice.