New rules for heart scan aims to reduce excessive radiation exposure

Instructions for a recalled device and drug used to produce scans to evaluate the heart have been revised in an effort to determine what may have caused excess radiation in some patients.

The CardioGen-82 PET scan, made by Bracco Diagnostics Inc., is used to perform cardiac positron emission tomography (PET) scans with the radioactive drug rubidium (Rb)-82 chloride injection to evaluate the heart. The Food and Drug Administration (FDA) has received reports of two patients who received more radiation than expected from CardioGen-82. The excess radiation was due to strontium isotopes which may have been inadvertently injected into the patients due to a “strontium breakthrough” problem with the device.

At this time, the FDA believes that the risk of harm from this exposure is minimal, although any unnecessary exposure to radiation is undesirable. The estimated amount of excess radiation in the two patients received is similar to that other patients may receive with cumulative exposure to certain types of heart scans. It would take much more radiation to cause any severe adverse health effects in patients, the FDA says.

Patients who have recently had heart scans should talk to their health care professional if they have any questions. Patients who are planning to undergo heart scan should talk to the health care professional if they are unsure the type of planned heart scan and the radiation risks associated with the scan.

This week, the FDA announced that it had approved the new labeling for the Cardio-Gen-82, and that it will continue to investigate the root cause of this failure with the CardioGen-82 and will promptly notify the public with updates.