Safety and efficacy of a novel hepatobiliary MR contrast agent, Gd-DTPA-DeA: results of phase I and phase II clinical trials.

Purpose: To assess the safety, effective dose, and efficacy of a novel hepatobiliary MR contrast agent Gd-DTPA-DeA for imaging liver tumors, from the clinical phase I and phase II trials in Japan.

Materials And Methods: In a phase I trial, 33 healthy volunteers were intravenously administered a single dose of 0.03-10 micromol/kg of Gd-DTPA-DeA. In a nationwide phase II trial, 80 patients suspected to have hepatic mass were divided into three dosing groups: 2.5, 5.0, or 7.5 micromol/kg. T1-weighted gradient echo images were obtained before and after Gd-DTPA-DeA administration at three time points. Liver signal-to-noise ratio (SNR) and lesion-liver contrast-to-noise ratio (CNR) were calculated at each time point. A reading committee evaluated the contrast, diagnostic, and overall efficacy using a five-point scale.

Results: In a phase I trial, dosages up to 10 micromol/kg were well tolerated by healthy volunteers. In a phase II trial, the contrast, diagnostic, and overall efficacy increased dose-dependently. The overall efficacy was 63.0%, 85.2%, and 88.0%, for 2.5, 5, and 7.5 micromol/kg, respectively. Liver SNR and CNR increase was greater at late phase than at early phase. No serious adverse events occurred.

Conclusion: Gd-DTPA-DeA is a well-tolerated and promising contrast agent for liver MR imaging.