February 16, 2012

February 16, 2012 (Rockville, Maryland)— The US Food and Drug Administration (FDA) is notifying physicians that CardioGen-82 (Bracco Diagnostics), a generator used at clinical sites to produce the rubidium (Rb)-82 chloride injection used for cardiac positron-emission-tomography (PET) scans, will be returning to market [1].

For its return, the FDA-approved revised labeling for CardioGen-82 includes a new boxed warning regarding unintended radiation exposure when levels of strontium-82 (Sr-82) and Sr-85 in the Rb-82 chloride injection exceed "alert limits." The warning comes with enhanced testing information that establishes the limits for Sr-82 and Sr-85 levels in the generator eluate, and if the levels reach these alert limits, additional daily eluate testing is performed.

"The additional daily testing is necessary to promptly identify excess strontium levels, which indicate that the generator expiration is approaching," according to the FDA drug safety communication. "The revised labeling also includes new information to identify when a generator is expired and its use must stop."

As previously reported by heartwire , the FDA told physicians to stop using the CardioGen-82 last summer after identifying an increased risk of radiation exposure from the strontium-based isotope used in the test. Two patients received more than the expected radiation dose while undergoing cardiac PET scans with the Rb-82 chloride injection.

The device was voluntarily recalled by Bracco Diagnostics in late July. As part of its ongoing investigation, the FDA concluded that "improper usage" of the generator at certain sites likely caused the radiation exposure to patients and was not the result of faulty devices. In the alert, the FDA said that clinical sites should follow the new directions for using CardioGen-82 generator. The updated label is available here.