Serum and Urine Gadolinium Reference Intervals in Patients With Normal Renal Function Following Gadobutrol...

Area of Science:

• Radiology
• Pharmacokinetics
• Toxicology

Background:

• Gadolinium-based contrast agents (GBCAs) enhance MRI efficacy but raise concerns about retained gadolinium (Gd).
• Existing Gd reference intervals were established in GBCA-naive individuals with normal renal function.
• The study addresses the need to understand Gd clearance in patients post-contrast administration.

Purpose of the Study:

• To determine serum and urine gadolinium (Gd) clearance in patients with normal renal function after intravenous gadobutrol administration for MRI.
• To evaluate the applicability of current Gd reference intervals in the post-GBCA period.

Main Methods:

• Enrolled patients with normal renal function (eGFR ≥60 mL/min) and no recent GBCA exposure.
• Collected serum and urine samples at multiple time points up to 84 days post-gadobutrol MRI.
• Quantified Gd concentrations using inductively coupled plasma mass spectrometry (ICP-MS).

Main Results:

• Pharmacokinetic analysis indicated a multicompartment elimination model for Gd.
• 95% of patients had serum Gd levels below the unexposed reference interval by approximately 56 days.
• 95% of patients had urine Gd levels below the unexposed reference interval by approximately 132 days.
• No self-reported Gd-related toxicity was observed in the study cohort.

Conclusions:

• Current reference intervals for serum and urinary gadolinium clearance are not suitable for patients within 5 months post-gadobutrol exposure.
• The findings highlight the extended period required for gadolinium elimination from both serum and urine.