PERFUSION QUANTIFICATION OF LIVER METASTASES OF COLORECTAL CANCER TREATED WITH ANTI-ANGIOGENIC-BASED THERAPY: ASSESSMENT OF INTRA- AND INTER-OBSERVER REPRODUCIBILITY OF PARAMETERS IN THREE REGIONS OF INTEREST OUTLINING LESIONS

This study evaluated the reproducibility of dynamic contrast-enhanced ultrasound (DCEUS) parameters outlining liver metastases of colorectal cancer in 45 patients, before and after anti-angiogenic-based therapy. Tumor enhancement was quantified by drawing three regions of interest (ROIs): (i) outlining the tumor based on portal phase DCEUS images, (ii) in the hypo-enhanced center of the lesion and (iii) outlining the lesion using parametric imaging. Perfusion parameters were extracted from time-intensity curves. Another ROI was drawn in healthy liver parenchyma for normalization. Intra- and inter-observer reproducibility of these parameters was evaluated using intra-class correlation coefficients (ICCs). For the three ROIs, both intra- and inter-observer reproducibility were excellent (ICCs >= 0.9) for 50.8% absolute parameters and were moderate to good (0.7 <= ICC < 0.9) for 26.7% of them. In healthy liver parenchyma and for normalized parameters, reproducibility was moderate to excellent for 59.4% of intensity parameters and was low (ICC <0.7) for almost all temporal parameters. This study indicates that DCEUS is a reproducible tool for evaluating perfusion parameters. (C) 2019 World Federation for Ultrasound in Medicine & Biology. All rights reserved.