Will Return of CardioGen-82 Represent a 'Glowing' Comeback?

Washington, DCIt may be funny to see poor, hapless Homer Simpson bringing the Springfield nuclear power plant to a boil and glowing green as a result, but when two CardioGen-82 heart patients set off airport security scanners after undergoing nuclear testing, the fallout is anything but humorous.

The manufacturer of CardioGen-82, Italy's Bracco Diagnostics, pulled the trigger on a voluntary recall of its product last year. The US Food and Drug Administration (FDA), for its part, launched an investigation to determine if the high dosages of radiation experienced by the two heart patients who both had nuclear imaging done at the same facility in Sarasota, Florida was the result of a problem with CardioGen-82 PET, or the facility itself, or a combination of both.

In a release in May of this year, the FDA announced that it had found improper usage of CardioGen-82 during a cardiac PET scan at "certain clinical sites" deemed responsible for the high radiation levels in the two patients in question. That statement does not suggest a problem with the product.

However, in its original Drug Safety Communication (7/26/11) released almost a year ago following the voluntary recall the FDA did, it did indeed state it had identified manufacturing deficiencies with CardioGen-82. "To date, these deficiencies do not appear to have been related to the excessive radiation exposure detected in some patients," the FDA said at the time.

In its most recent statement (5/11/12), the FDA suggested the reason for the high radiation levels in patients was related to the "administration of CardioGen-82 generator eluates that contained excessive concentrations of strontium-82 (Sr-82) and strontium-85 (Sr-85).

"This excessive release of Sr-82 and Sr-85 in generator eluates is known as 'strontium breakthrough,'" the FDA statement continued. "FDA believes it is unlikely that this excessive exposure posed significant risks to patients, though exposure to any excessive radiation is undesirable."

While the FDA said that any manufacturing deficiencies the agency may have found were not related to the potentially improper use of CardioGen-82 during cardiac PET imaging, the federal regulator stated nonetheless it continues to work with the manufacturer "to resolve their manufacturing deficiencies."

That statement suggests that manufacturing deficiencies may be an ongoing challenge. It also suggests that while manufacturing deficiencies may not have caused the higher-than-normal PET radiation dose in patients, it may have been a contributing factor.

The FDA went on to say in its May statement that it continues to work with Bracco to revise the labeling for CardioGen-82 with an eye to better describe the proper way to use the generator necessary for delivery of the CardioGen-82. The agency noted there appeared to be insufficient documentation with regard to compliance at the two clinical sites related to the patients exhibiting higher levels of radiation.

The FDA concluded that in tandem with efforts to resolve manufacturing deficiencies related to Bracco imaging, and improve labeling and guidelines on how to use the generators necessary for strontium breakthrough testing, the agency is moving ahead with the implementation of "a plan for the return of CardioGen-82 to the market."

CardioGen-82 is returning. Will it be a 'glowing' comeback? Time will tell…