Medical Tests Can Trigger Airport Radiation Alarms

Radioisotopes can be detected for up to 3 months, report says

FRIDAY, July 22, 2005 (HealthDay News) -- Navigating airport security systems can be annoying, particularly for patients who undergo certain medical treatments or diagnostic tests that involve radioactive isotopes that can trigger radiation alarms.

In some airports around the world, passengers have been stopped and delayed when the small amounts of radiation used in medical tests, such as cardiac stress tests, set off a radiation alarm, according to a report in the July 23 issue of The Lancet.

This shouldn't pose a problem for air travelers in the United States because there are no radiation detectors at airport checkpoints, according to Consumer Reports and a U.S. government source. There are, however, detectors at some tunnels and train and subway stations and in some public buildings, such as the White House. In fact, 20 years ago a person was detained in the White House when radiation from a medical test set off a detector.

In the new report, lead author S. Richard Underwood, a professor of cardiac imaging at Imperial College in London, England, and his colleagues recounted the story of a 55-year-old commercial airline pilot who was stopped, detained and questioned when thallium set off a radiation alarm at the Moscow airport.

The pilot was detained both entering and leaving Russia, and questioned for five and three hours, respectively, according to Underwood. "This is not the first time that's happened with the recent security measures. It does keep cropping up," he said.

Underwood noted that triggering detectors occurs because the radiation detectors -- set to detect radiation that might reveal the presence of a "dirty bomb" -- are set to high levels of sensitivity. "The amount of radiation involved in doing medical scans is very tiny," he said. "In terms of a radiation, it is not an issue."

Depending on what radioactive isotopes are used for medical procedures such as thyroid or bone scans or for iodine therapy, they can remain in the body and be picked up by radiation detectors from a couple of days to more three months, Underwood noted.

To deal with the problem, Underwood said he now asks patients who get nuclear scans if they are going to be flying within the next month. "If they say yes, we give them a little form declaring what they've had and why and how long it might be detectable, just to ease their passage through the security officials."

To avoid delays, U.S. Transportation Security Administration spokeswoman Deirdre O'Sullivan advised that if you have a hidden medical condition, you should tell the screener about it before passing through the checkpoint.

Airport screeners are trained to deal with people with hidden medical conditions, such as pacemakers, O'Sullivan said. "People can ask for a physical pat down," she said. "They do not have to go through the metal detector. There are also opportunities for private screenings."

David S. Stempler, president of the Air Travelers Association, suggests getting a letter from your doctor saying you've just had a radiological procedure. "Some folks have done that with metal hip and knee replacements," he said.

Dr. Lionel S. Zuckier is director of nuclear medicine and PET at the University of Medicine and Dentistry of New Jersey. He has tested a variety of radiation detectors used by the U.S. Department of Homeland Security to measure how sensitive they are.

He has also created a Web site so physicians can calculate the likelihood of a patient setting off a radiation detector, based on the dose of an isotope and the sensitivity of the detectors.

"For practitioners, the Web site has the option of printing a letter for the patient with a verifiable phone number," Zuckier said. The letter also tells the patient how long the particular isotope will remain detectable.

More information

The Transportation Security Administration can tell you more about traveling when you have a hidden medical condition.

SOURCES: S. Richard Underwood, professor of cardiac imaging, Imperial College, London, England; Deirdre O'Sullivan, spokeswoman, Transportation Security Administration, Washington, D.C.; David S. Stempler, president, Air Travelers Association, Potomac, Md.; Lionel S. Zuckier, M.D., director of nuclear medicine and PET, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark; July 23, 2005, The Lancet
Consumer News