Fibrosis, portal hypertension, and hepatic volume changes induced by intra-arterial radiotherapy with ⁹⁰Yttrium microspheres

Purpose: To identify changes in hepatic parenchymal volume, fibrosis, and induction of portal hypertension following radioembolization with glass microspheres for patients with metastatic disease to the liver. Results: In our series of sequential bilobar (n = 17) treatments, a mean decrease in liver volume of 11.8% was noted. In this group, a mean splenic volume increase of 27.9% and portal vein diameter increase of 4.8% were noted. For patients receiving unilobar treatments (n = 15), mean ipsilateral lobar volume decrease of 8.9%, contralateral lobar hypertrophy of 21.2%, and a 5.4% increase in portal vein diameter were also noted. These findings were not associated with clinical toxicities. Conclusion: ⁹⁰Yttrium radioembolization utilizing glass microspheres in patients with liver metastases results in changes of hepatic parenchymal volume and also induced findings suggestive of fibrosis and portal hypertension. Further studies assessing the long-term effects are warranted.