Citizen Petition Seeks Removal of Boxed Warnings on Ultrasound Contrast Agents; New Safety Data Cited
- Category: Press Releases
- 07 October 2011
CHICAGO -- Cross-specialty international medical experts filed a Citizen Petition with the FDA today, asking the agency to remove boxed warnings from ultrasound contrast agents, stating that the warnings deter use of a safe, inexpensive and radiation-free diagnostic imaging tool with potential life-saving benefits for patients.
According to the petition filed by the International Contrast Ultrasound Society (ICUS), a significant body of new research shows a favorable cost-benefit ratio for contrast-enhanced ultrasound (CEUS) imaging. This research was not available when the boxed warnings were mandated by the FDA, according to the ICUS petition.
The organization, which has members in 59 countries, represents cardiologists, radiologists, and other physicians and imaging professionals who use CEUS imaging. The organization voted at its annual conference and board meeting held at the end of last month, in Chicago, to formally request FDA action on the black box warning.
“The boxed warnings are inconsistent with FDA standards for use of boxed warnings and stand in direct opposition to the FDA’s statutory responsibility to protect the health of the American public,” according to Dr. Steven Feinstein, a cardiologist at Rush University Medical Center in Chicago and ICUS Co-President.
“As new scientific evidence emerges, the key issue remains whether the available body of safety data warrants the most serious level of caution -- the boxed warning,” said Dr. Feinstein. “Pursuant to the FDA’s own guidance, the answer is clear: Ultrasound contrast agents are exceedingly safe and do not warrant boxed warnings,” he continued.
Recent studies now show “no increased safety signal even among the sickest patients,” according to the ICUS petition, which described six new safety studies undertaken by the product sponsors at the request of the FDA, as well as “numerous” other independent studies recently published in peer-reviewed journals.
Ultrasound contrast agents are approved in the U.S. for cardiac imaging only. Additional non-cardiac uses of CEUS are under review by the FDA, but throughout Europe, Canada, Asia and Brazil CEUS is safely and routinely used to pinpoint cancers, monitor chronic gastro-intestinal diseases, detect vascular disease, as well as diagnose heart disease and serious medical conditions elsewhere in the body.
“The United States is actually behind the rest of the world when it comes to using contrast-enhanced ultrasound,” according to Dr. Barry Goldberg, Co-President of ICUS and director of the Division of Diagnostic Ultrasound at Thomas Jefferson University Hospital in Philadelphia.
CEUS is simply an "enhanced" ultrasound exam that uses a biocompatible contrast agent to improve the clarity of an ultrasound image. The contrast agent is injected into the patient’s arm vein during the ultrasound exam. As it flows through the bloodstream, it reflects ultrasound waves and lights up the image seen on the television-like screen. “By improving the ultrasound image, CEUS can reduce the risk of a misdiagnosis or a missed diagnosis,” according to Dr. Michael Main, an expert in CEUS safety and Treasurer of ICUS. Main is a cardiologist and director of the echocardiography laboratory at Mid-America Heart Institute/Saint Luke’s Health System in Kansas City.
In addition, the procedure does not expose patients to ionizing radiation. The ultrasound contrast agent, which does not contain dye, is metabolized and expelled from the body within minutes. By comparison, patients are exposed to ionizing radiation when they undergo SPECT (nuclear) imaging, CT, PET scans, X-ray and angiography. “Although these (other) diagnostic tests may be useful when medically indicated, there is increased recognition of the over-utilization of radiation-based diagnostic imaging, with significant
health concerns due to radiation exposure even at low levels,” according to the petition, which also cited a recent American Heart Association report that medical imaging is “the largest controllable source of radiation exposure in the US population.”
The Joint Commission, which accredits more than 19,000 health care programs in the US, recently stated that exposure to ionizing radiation has nearly doubled over the past two decades, and physicians may order tests involving exposure to radiation with no knowledge of when the patient was last irradiated or how much radiation the patient received.
Ultrasound equipment is also being used to image a growing number of severely obese patients who often cannot be imaged with other imaging technology,” according to the petition.