The U.S. Food and Drug Administration (FDA) is notifying healthcare professionals today not to use CardioGen-82 (rubidium-82 chloride injection), prompting its manufacturer, Bracco Diagnostics, to voluntarily recall the cardiac PET imaging agent.
Today's FDA announcement follows the agency's July 15 communiqué that the agency had received two reports in which patients injected with CardioGen-82 had received increased radiation exposure during the PET scans. The increased radiation was due to strontium isotopes that may have been inadvertently injected into patients because of a "strontium breakthrough" problem with CardioGen-82, the FDA noted.
Based on its follow-up investigation, the FDA has determined that the current CardioGen-82 manufacturing procedures "are not sufficient to ensure reliable performance of the generator used to produce the rubidium-82 chloride injection."
The agency added that it's also currently investigating whether testing procedures at the clinical sites that use CardioGen-82 are sufficient to detect strontium breakthrough.
In the meantime, the FDA recommends that healthcare professionals use alternatives to the CardioGen-82 generator when planning nuclear medicine cardiac scans.
The FDA said it will also continue to work with the Nuclear Regulatory Commission and Bracco to determine the cause for the increased radiation exposure detected in the two patients. The extent to which any additional patients may have received increased radiation exposure is also being investigated.
Radiation sensors detected the additional radiation in the two patients at an international border crossing. The pair had received PET scans two and four months prior, respectively, and reported no other exposure to radioactive substances. Because rubidium-82 has a half-life of 75 seconds, compared with 25 days for strontium, the FDA believes that the residual radiation was due to strontium breakthrough.
According to the July 15 document, the amount of radiation the two patients received (about 90 mSv, versus 2.8 mSv for a normal CardioGen-82 exam) is similar to the cumulative dose that some patients might receive with other types of radionuclide heart scans. It would take a much larger dose of radiation to cause severe adverse health effects, the agency added.
