Diffusion-Weighted Mr Imaging Of Advanced Hepatocellular Carcinoma Treated With The Oral Multikinase Inhibitor Sorafenib

Objective: To evaluate diffusion-weighted imaging (DWI) in the response monitoring of hepatocellular carcinoma (HCC) treated with the oral multikinase inhibitor Sorafenib.Materials and Methods: 10 patients with histologically proven advanced HCC were examined on a 1.5 T whole-body-unit before and during Sorafenib therapy. Navigator-respiratory triggered echoplanar imaging (EPI) DWI with bvalues of 50/400/800 s/mm(2) was performed in addition to the standard liver protocol. Size, location and ADC were recorded for designated target lesions before and during Sorafenib therapy. ADC changes were analyzed with regard to potential diagnostic information for treatment monitoringResults: Mean time-to-progression was 6.6 months. All lesions showed an initial ADC decrease in the first MR scan 4 weeks after onset of Sorafenib. Areas of ADC reduction could be attributed to focal hyperintensities in the non-enhanced T1 images, suggesting intralesional hemorrhage. In the second MR scan 10 weeks after treatment onset, the majority of lesions showed re-increasing ADC values. In the long-term follow-up, constant ADC decline was observed in the majority of lesions.Conclusion: HCC lesions exhibit characteristic but unusual ADC changes during Sorafenib therapy. The ADC changes reflect pathophysiologic mechanisms in the tumor (most probably hemorrhagic necrosis) induced by this novel targeted agent early after therapy onset. In the long-term follow-up, changes in DWI may indicate tumor progression.