Prognostic prediction of apparent diffusion coefficient obtained by diffusion-weighted MRI in mass-forming intrahepatic cholangiocarcinoma.

BACKGROUND

We evaluated apparent diffusion coefficient (ADC) of diffusion-weighted image MRI as a prognostic factor for mass-forming intrahepatic cholangiocarcinoma (IHCC).

METHODS

We enrolled 26 patients who had undergone hepatic resections for mass-forming-type IHCC in this study, and calculated their mean ADC, using diffusion-weighted image MRI (b: 0, 20, 800 seconds/mm ; 1.5 T MRI). Patients were divided into the ADC and the ADC groups at the median ADC value (n = 13 for both). We also immunohistochemically evaluated hypoxia-inducible factor (HIF)-1α in tumor tissue.

RESULTS

Median age in the ADC was older (P = .03), and showed significant higher rate of scirrhous tumor (P = .02). The 5-year overall survival rate in the ADC group was significantly worse than in the ADC group (P = .04). In multivariate analysis, hilar tumor, portal vein invasion and low ADC were independent prognostic factors (P < .05). The ADC group also had a higher rate of high HIF-1α expression than the ADC group (P < .05). Representative case of ADC group showed rich stroma and high HIF-1α expression.

CONCLUSIONS

The ADC values in MRIs can predict IHCC prognosis, and correlated with stromal density and HIF-1α expression.