Our new publication: Gadolinium Elimination in a Gadolinium Deposition Disease Population After a Single Exposure to Gadolinium-Based Contrast Agents.

Our latest research effort is now in ePub form. Unfortunately the copy I have is the author's ePub copy which the journal does not allow authors to share, but it now is in the public arena. This means this article is now obtainable.

Gadolinium Elimination in a Gadolinium Deposition Disease

Population After a Single Exposure to Gadolinium-Based Contrast Agents

Joana Ramalho, MD, Miguel Ramalho, MD, and Richard C. Semelka, MD

Purpose: This study documents the gadolinium (Gd) content in urine over time

after the administration of a single dose of Gd-based contrast agent (GBCA) in

patients diagnosed with Gd deposition disease.

Materials and Methods: In this retrospective observational study, 45 subjects

with normal renal function who had performed 1 contrast-enhanced magnetic res-

onance imaging and had a nonprovoked (native) 24-hour urine test for Gd quan-

tification after the examination were evaluated. The GBCA brand and the time

interval in days between the GBCA administration and 24-hour urine Gd mea-

surements were recorded. Log-log plot visualization of time points for urine Gd

content was obtained.

Results: Time points collected for urine Gd content showed that Gd was above

the reference levels for 3 months postinjection. The urinary concentration of

Gd was similar for all agents, including linear and macrocyclic. The urinary con-

tent decreased in a dog-leg fashion. Gd urine content was substantially elevated at

1 month and decreased to remain above the accepted normal range by 3 months.

Conclusions: Gd is retained in the body and shows demonstrable continued

spontaneous elimination in urine for at least several months after administration,

including the most stable macrocyclic agents. The Gd elimination pattern shows a

logarithmic decrease pattern between 1 and 3 months for all agents, regardless of

their structure.

(Invest Radiol 2025;00: 00–00)

The Discussion of the paper does now describe that MR facilities should no longer tell patients that Gd is completely out of the body by 24 or 48 hours, which perhaps almost all MR centers are now telling patients. This practice must now stop because this is false.

We also have stated that it is imperative that companies do controlled studies showing in normal subjects undergoing MRI with their agent the pattern of Gd elimination in a controlled setting. What we have not written in the paper is that the standardized time points should be:

1 day, 3 days, 1 week, 2 weeks, 1 month, 2 months, 3 months, 4 months, 6 months, 1 year. 10 subjects may be sufficient for this, because the numbers appear to be very consistent between individuals. We recommend that eGFR be > 90, as an entry criteria... A future report could look at poorer renal function patient groups.

In a separate report, they should also look at chelating patients who have received their agent at 3 months and again at 1 year, with the best available chelator, which at this time is 5 ml of Ca-DTPA.. Years into the future also appropriate: 2 years, 5 years, 10 years. This long term removal paper should be a separate paper because by its nature the results will not be available for years, but 3 month and 1 year time frames are appropriate for an initial publication report out within 1.5 years time.. This chelating studies also is very simple to do, and will rectify the false information that some macrocyclics cannot be removed from subjects

Individuals in touch with health care members of the incoming new administration should bring this referenced paper, and this blog to their attention. These studies are easy and relatively inexpensive to do, and as we write in the paper, it defies reason that the FDA had not already requested companies to do this.

Richard Semelka, MD.