Purpose: We investigated whether functional future remnant liver volume (fFRLV), assessed using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI), could evaluate regional liver function in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) and help establish the indication for hepatectomy.
Methods: The subjects of this study were 12 patients with PVTT [PVTT(+) group] and 58 patients without PVTT [PVTT(-) group], from among 191 patients who underwent hepatectomy of more than one segment for HCC. We calculated the liver-to-muscle ratio (LMR) in the remnant liver, using EOB-MRI and fFRLV. Preoperative factors and surgical outcome were compared between the groups. The LMR of the area occluded by PVTT was compared with that of the non-occluded area.
Results: The indocyanine green retention rate at 15 min (ICG-R15) and liver fibrosis indices were increased in the PVTT(+) group, but the surgical outcomes of patients in this group were acceptable, with no liver failure, no mortality, and no differences from those in the PVTT(-) group. The fFRLV in the PVTT(+) group was not significantly different from that in the PVTT(-) group (p = 0.663). The LMR was significantly lower in the occluded area than in the non-occluded area (p = 0.004), indicating decreased liver function.
Conclusion: Assessing fFRLV using EOB-MRI could be useful for evaluating regional liver function and establishing operative indications for HCC with PVTT.
Keywords: EOB-MRI; Functional liver volume; Portal vein tumor thrombus; Regional liver functional reserve.