Why You Need to Track Contrast Dose Exposure

April 10, 2018

As with any drug, radiologists need to consider the benefit-risk profile of anything given to a patient, and GBCAs are no exception.

When it comes to offering the most comprehensive, accurate diagnosis possible, contrast agents are often one of your most invaluable tools. But, how frequently do you stop to consider whether your patients-particularly those who have routine studies-are experiencing any side effects or negative impacts from contrast dose exposure?

In recent years, the Food & Drug Administration (FDA) has expressed concern over deposits of gadolinium-based contrast agents (GBCAs) in the body, particularly in the brain. While the FDA didn’t recommend curtailing GBCA use, the American College of Radiology and American Society of Neuroradiology (ASNR) published recommendations, calling for you to do a risk-benefit analysis with each GBCA use, particularly with pediatric patients and those who undergo repeated GBCA-enhanced MRI studies.

Diagnostic Imaging spoke with Bayer’s Sheela Agarwal, MD, medical affairs head for Americas, radiology, and Joanne Hoener, RT, clinical specialist, to discuss the importance of contrast dose tracking and management.

DI: Overall, in radiology today, how important is contrast dose tracking and management?

Hoener: I think that when we talk about contrast dose management, we have to think about where we’ve been historically. For many years in radiology, a lot of the medication that’s been delivered in the form of contrast media has been done by hand. So, the technologist or the healthcare provider for the study is manually recording all the information related to the contrast media. That goes across MR and CT. It’s just a practice that’s gone on a long time in radiology. Over time, the injector platforms have evolved and improved, and we now have the ability to get good accurate information directly from the source-the injector. And, we have the ability to send that information to electronic medical records, for example, to the PACS system where the radiologist is reading exams. Or, we can send very accurate information directly and automatically right into the radiologist’s report and send the details into the RIS. When you look at contrast dose management and tracking of contrast in radiology, you have to think about the evolution. Although these technologies are available today, the adoption is slower, in my view, than it should be. I think we have these technologies that can more seamlessly take advantage of more accurate documentation and provide a better view of the patient experience with contrast in radiology.

Agarwal: Historically, contrast dose has been an afterthought. In general, contrast is a small part of a radiology exam. The injector, the contrast, everything is dwarfed by the scan, the scanner itself, the radiation, the sequences. It’s taken time to evolve in terms of its importance, and everything going on for the past few years on this topic has made it that much more relevant.

DI: How big of a role does contrast dose play in treatment and why?

Hoener: I’m not sure contrast dose management plays a role in treatment, but I do think contrast dose management plays a role in overall patient management. When you look at contrast dose management through the window of doing it accurately, with automation, and directly from the source of the injector, what you get is very good information about the patient and their history when they’re inside your enterprise. So, the radiologist or the individual that’s managing that patient in radiology that day has an opportunity to go back and historically look at the patient’s previous contrast administration and glean any information they can to be better informed about the contrast that might be given for that day’s procedure. So, I don’t necessarily look at it so much as in the treatment, but obviously, contrast media is very important in the diagnosis. And, then, additionally, it plays a role in the overall patient management and, potentially, they’re outcomes.

DI: How integral are dose management systems when it comes to the clinical implications of gadolinium in the body?

Hoener: We don’t know what exactly the question is in regard to gadolinium in the body. We don’t necessarily know what the mechanism is, but one thing we do know is that we could be served much better if we have really good, strong data to look at. Right now, because we’re still in this era where most of the information that we have to look at historically has been manual or incomplete, it’s very difficult to answer those questions. A comprehensive contrast dose management solution informs the patient’s electronic medical record about today’s exam, but we also need to think about how all these solutions can really help us in the future as we try to unlock the mystery of what’s specifically going on with gadolinium in the body. Having a really good solid database with good, accurate information would be extremely helpful in that regard.

Agarwal: There are no known clinical implications or clinical symptoms associated with the gadolinium retention in the body or brain right now. When talking about dose management, it’s much more about the accurate documentation and the role that will play going forward in terms of being able to perform good sound research to answer those questions.

DI: What are the implications of the latest FDA actions? Why is this important, and what might it change?

Agarwal: In terms of the FDA actions, I think there are two things that are important to note. The FDA has mandated a requirement that all the companies performing post-marketing research investigate whether there are any clinical implications of the gadolinium retention in the brain and body. As we just mentioned, in addition to the research that the FDA is mandating, I think it’s demonstrating the need for additional, sound study by the research community as a whole. Documenting this information about gadolinium retention and having it available in the patient record will be very important to inform that research.

The other implications of the latest FDA action is, for the first time that I’m aware, the FDA has called out special populations they have noted might require extra attention in terms of the amount of contrast being administered. One of those groups are patient who get multiple scans. These are patient with chronic illnesses, risk factors that would require them to have frequent screening, and pediatric populations that might cumulatively have multiple doses over time. Again, it’s impossible to really note these population unless the information is documented somewhere.

DI: How has the ACR gotten involved with the use of gadolinium?

Hoener: The ACR has taken a lead here, making some comments similar to what the Joint Commission says about ensuring the radiologist’s report reflects the agent, the volume, the dose, and the catheter gauge as long as that information isn’t captured somewhere else. The ACR is also asking for documentation, but they haven’t specifically said it needs to be from the source. They did develop a position statement with the ASNR where they reiterated every time GBCAs are delivered that the dose and specific agent should be documented. For many years when different agents came to market, you’d see documentation just said “GAD” and didn’t call out the agent. The ACR and ASNR now say they want to capture the brand and volume in the patient record.

DI: How is all of this different, for better or worse, since GBCAs received first approval in the late 1980s?

Agarwal: I think one of the most important trends to note over the past 30 years is the role that contrast plays as an invaluable diagnostic tool in diagnosis and patient management. Time and again, it’s been demonstrated that contrast and contrast-enhanced examinations inform change and lead patient management. Contrast isn’t going away. The role it plays in diagnosis has become even more important today. I think it’s something physicians have come to rely on, and we’re only finding more and more valuable information it provides in terms of patient diagnosis over time.

Essentially over time, there’s been an evaluation as to how the FDA has approved contrast agents. Historically, it was much more general approval for whole body use. Now, however, as there are multiple different brands available with slight differences among the different agents, they are approved for particular indications.

DI: Based on these changes, what do radiologists needs to keep in mind the most when using GBCAs?

Agarwal: As with any drug, radiologists and physicians should consider the benefit-risk profile of anything given to a patient, and GBCAs are no exception. Overall, and in the big picture, there’s no doubt about the benefit of contrast agents, but on a per-patient basis, I think there will probably be a trend toward more carefully evaluating each patient coming in. What is their scan for, and how can we tailor the need for contrast or the type of contrast they should specifically receive? I think that’s probably the most important thing radiologists should keep in mind.

Each patient needs to be evaluated as an individual. And, the reason they’re coming in for the exam needs to be evaluated as to the value that a contrast agent can provide. That applies over time for the follow-up exams and the amount of contrast they’re exposed to cumulatively over time. There are things that radiologists are well-versed in when it comes to radiation dose, but the same analysis could be applied to contrast dose, as well. For example, radiologists consider radiation dose when deciding if a patient should have another CT scan if they had one the day before. Historically, they haven’t considered the same contrast dose impact, but those are things they need to be keeping in mind.