Hepatic parenchymal changes after intraarterial Y-90 therapy: CT findings

The serial contrast material-enhanced computed tomographic scans of 23 patients treated with intraarterial yttrium-90 microspheres as therapy for hepatic metastatic disease were reviewed for evidence of parenchymal changes in the liver in areas not involved with tumor. Irregular low-attenuation geographic areas that developed in the hepatic parenchyma after therapy were graded as mild, moderate, or severe and were evident in 12 of 23 patients. In nine cases of mild to moderate changes in the hepatic parenchyma, the abnormality was either focal or asymmetric. In all three patients receiving the highest dose (15,000 cGy), severe diffuse parenchymal changes were seen in all hepatic segments. In the remaining 11 patients, no parenchymal changes were seen. The most pronounced changes were seen at 8 weeks after therapy and were partially or completely reversible at 16-24 weeks. All patients had minimal or no change in liver function and no clinical sequelae attributable to liver injury.