Purpose: To evaluate the efficacy and safety of gadoxetic acid disodium, or Gd-EOB-DTPA, as a tissue-specific hepatobiliary contrast agent at computed tomography (CT) in patients with liver metastases.
Materials and methods: Fifteen patients with known liver metastases underwent CT before and at 30, 80, and, in seven cases, 150 minutes after initiation of intravenous infusion of 0.2, 0.35, and 0.5 mmol Gd/kg gadoxetic acid disodium (five patients per dose group). Attenuation in liver tissue and metastases was measured at each time point. Visualization of metastases, bile ducts, and gallbladder was graded subjectively by two investigators aware of the dose administered and the imaging time point. Patients were monitored for adverse events clinically, and numerous laboratory tests were performed over the 24 hours after administration of the contrast material.
Results: The net mean increase in liver attenuation with 0.2, 0.35, and 0.5 mmol Gd/kg was 13 HU +/- 4 (standard deviation), 27 HU +/- 6, and 34 HU +/- 8, respectively. Visualization of liver metastases with doses of 0.35 and 0.5 mmol Gd/kg was graded as good or excellent. Visualization of the gallbladder and common bile duct with doses of 0.35 and 0.5 mmol Gd/kg was improved from minimal to excellent in 89% and 57% of patients, respectively, on 80-minute postcontrast scans. No serious adverse events occurred. Four of 15 patients experienced mild or moderate adverse events possibly or probably related to the contrast medium. Levels of aspartate and alanine aminotransferase increased in three patients by 12-26 and 21-48 U/L, respectively, from normal or moderately elevated baseline levels. These changes may be related to the contrast medium or to the metastases.
Conclusion: Patient tolerance of gadoxetic acid disodium was acceptable, and liver enhancement and visualization of liver lesions and the biliary system was improved at CT.