Choline C 11 injection, the agency said, has been made by a few facilities in recent years. But the approval yesterday marked the first time that FDA has authorized a facility to manufacture the imaging agent.

The facility is the Mayo Clinic in Rochester, Minnesota.

Choline C 11 injection, FDA said, is for use in patients who have been treated for prostate cancer but whose blood prostate-specific antigen levels are nonetheless increasing. I.V. injection of the imaging agent into a patient during positron emission tomography yields a tomogram that suggests specific sites to biopsy and test for cancer.

FDA said the only type of adverse event reported in published studies of choline C 11 injection was a mild skin reaction at the injection site.

The FDA-approved labeling for the new product is not yet available to the public.

Until 1997, the preparation of imaging agents for use during positron emission tomography was generally viewed as a compounding procedure performed locally because of the relatively short half-life of the radioactive tracer. The half-life of the radioactive tracer in choline C 11 injection, for example, is 20 minutes.

But the Food and Drug Administration Modernization Act of 1997 directed FDA to establish an approval process and current good manufacturing practice requirements for positron emission tomography drugs.

The agency set a deadline of June 12, 2012, for facilities to submit a drug application for each of their positron emission tomography drugs. By December 2015, only those facilities that have an approved new drug application, approved abbreviated new drug application, or in-effect investigational new drug application for a positron emission tomography drug may legally produce that drug.