Tuesday, 4 August 2015

Monitoring NEDA with Gd-enhanced MRI

How safe are frequent Gd-enhanced MRI scans? #MSBlog #MSResearch


"The following communication from the FDA is worrying, it suggest that people who undergo frequent gadolinium-enhanced MRI accumulate gadolinium (gD) in the brain long after the last administration. At present it unknown whether this is harmful or not. I have asked Professor David Miller to advise on this as it is very relevant to monitoring MS. We use Gd in clinical trials and routine clinical practice to monitor for active disease. In future we may have to limit ourselves to T2 scans only and count new and enlarging T2 lesions only. Please watch this space. Can I suggest you keep a log of how many Gd-enhanced scans you have had in case the information is needed for large-scale epidemiological studies to assess the effect of Gd on brain function."

FDA Drug Safety Communication: FDA evaluating the risk of brain deposits with repeated use of gadolinium-based contrast agents for magnetic resonance imaging (MRI)

Safety Announcement

The U.S. Food and Drug Administration (FDA) is investigating the risk of brain deposits following repeated use of gadolinium-based contrast agents (GBCAs) for magnetic resonance imaging (MRI). MRIs help detect abnormalities of body organs, blood vessels, and other tissues. Recent publications in the medical literature have reported that deposits of GBCAs remain in the brains of some patients who undergo four or more contrast MRI scans, long after the last administration. It is unknown whether these gadolinium deposits are harmful or can lead to adverse health effects.

FDA, including its National Center for Toxicological Research (NCTR), will study this possible safety risk further. We are working with the research community and industry to understand the mechanism of gadolinium retention and to determine if there are any potential adverse health effects. Based on the need for additional information, at this time, we are not requiring manufacturers to make changes to the labels of GBCA products.

To reduce the potential for gadolinium accumulation, health care professionals should consider limiting GBCA use to clinical circumstances in which the additional information provided by the contrast is necessary. Health care professionals are also urged to reassess the necessity of repetitive GBCA MRIs in established treatment protocols.

Patients, parents, and caregivers should talk to their health care professionals if they have any questions about the use of GBCAs with MRIs. This issue affects only GBCAs; it does not apply to other types of scanning agents used for other imaging procedures, such as those that are iodine-based or radioisotopes.

After being administered, GBCAs are mostly eliminated from the body through the kidneys. However, trace amounts of gadolinium may stay in the body long-term. Recent studies conducted in people and animals have confirmed that gadolinium can remain in the brain, even in individuals with normal kidney function.1-21 Available information does not identify any adverse health effects.

We urge health care professionals, patients, and parents/caregivers to report possible side effects involving GBCAs to the FDA.

4 comments:

  1. I was wondering about this - it was a gD scan that got me diagnosed, however every scan I've had after that hasn't used gD. My neurologist is one of the leading MS researchers in Australia, so I trust them, but I have wondered why there is a disconnect between their practice and what I see on here. Any thoughts?

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  2. A bit alarming as I've had quite a few GD scans but how the heck are we meant to know what side effects to report as the FDA suggests, when it also says available information has not identify any adverse health effects???

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  3. I had three MRIs in 20 months - and only the third one had Gad used. The first MRI was to "rule out" MS as I didn't fit the "usual presentation" for MS (i.e. I was too old for MS and I didn't have relapses!). However MRI No 1 was considered conclusive and I was diagnosed with MS on the basis of that MRI plus the physical symptoms. I have always wondered why Gad was not used for my first two MRIs - maybe it might turn out to have been a good thing after all that it wasn't used..............

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  4. In the meantime, it would be prudent to use macrocyclic gadolinium contrast agents - they hold the metal tightly, and are not prone to gadolinium leakage. Commercial macrocyclic contrast agents include Gadavist (gadobutrol), gadoteridol (ProHance), and gadoterate (Dotarem). In the future, agents with higher relaxivity and increased stability may be needed.

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