Chemotherapy-induced focal hepatopathy in patients with gastrointestinal malignancy: gadoxetic acid--enhanced and diffusion-weighted MR imaging with clinical-pathologic correlation

Abstract

Purpose: To retrospectively evaluate findings of chemotherapy-induced focal hepatopathy (CIFH) on gadoxetic acid-enhanced magnetic resonance (MR) and diffusion-weighted (DW) images and to determine imaging features that are most helpful in differentiating CIFH from metastasis.

Materials and methods: This retrospective study was approved by the institutional review board, and informed consent was waived. MR images, including DW images and gadoxetic acid-enhanced images, from 12 patients (four men, eight women; age range, 25-64 years) with 15 CIFHs were reviewed independently and in consensus by two radiologists and were compared with those obtained in 20 control patients (12 men, eight women; age range, 32-84 years) with 30 hepatic metastasis who were matched for tumor size, primary organ, and chemotherapy regimen. Interobserver agreement was assessed with κ statistics, and univariate analysis was performed for comparisons. For quantitative analyses, apparent diffusion coefficients (ADCs) and lesion-to-liver contrast ratios (CRs) were measured. Histopathologic examinations were performed for CIFHs.

Results: Histopathologic examination revealed that the development of CIFHs was attributable to accentuated manifestations of sinusoidal obstruction syndrome. Interobserver agreement was excellent (κ > 0.85). An ill-defined margin on hepatobiliary phase (HBP) images was the most discriminating independent variable in the differentiation of CIFH from metastasis (odds ratio, 16; P = .009). ADC and CR values in CIFH group were significantly higher than those in metastasis group (P < .001 and P = .041).

Conclusion: CIFH should be considered a mimicker of metastasis in patients with gastrointestinal malignancy during chemotherapy. CIFH can be differentiated from metastasis on the basis of gadoxetic acid-enhanced MR and DW imaging findings; an ill-defined margin on HBP images was especially characteristic.