[ RadSafe ] Traveling After Nuclear Medicine Procedure May No t Fly
Baratta, Edmond J
EBARATTA at ORA.FDA.GOV
Fri Jul 22 13:13:34 CDT 2005
The hospitals (at least in this area) are very reluctant to give out any
information (notice) and only will if really pressed. Stress tests also use
Technetium-99m as the radionuclide. They give a 30 mCi injection at the
time of the test and six hours later (~ 1 half-life) give total another 30
mCi. This is a total of 45 mCi. It takes ~ 24 hours to clear most of it by
decay and elimination (~2.7 mCi left). The hospital here makes no mention
of not using public transportation. Fortunately there is none (public
transportation) nearby, except after a mile walk.
Edmond J. Baratta
Radiation Safety Officer
Tel. No. 781-729-5700, ext 728
FAX: 781-729-3593
-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf
Of Susan Gawarecki
Sent: Friday, July 22, 2005 1:26 PM
To: RADSAFE
Subject: [ RadSafe ] Traveling After Nuclear Medicine Procedure May Not Fly
Traveling After Nuclear Medicine Procedure May Not Fly
http://www.medpagetoday.com/Radiology/GeneralRadiology/tb1/1403
By Michael Smith , MedPage Today Staff Writer
Reviewed by Zalman S. Agus, MD; Emeritus Professor at the University of
Pennsylvania School of Medicine.
LONDON, July 21-The threat of terrorism has made it tougher for patients
who have undergone radioisotope procedures to slip quietly past
radiation detectors deployed in airports and many other public places.
A 55-year-old commercial pilot learned that the hard way, when he was
detained for questioning at Moscow's airport two days after having a
thallium-201 myocardial perfusion scintigram.
After "extensive interrogation," the pilot was released, only to trip
radiation detectors again four days later while leaving Moscow,
according to a case report in the July 23 issue of The Lancet.
The case and others like it suggest "it is important to warn patients
having had a thallium scan that they may trigger radiation detectors for
up to 30 days," wrote Richard Underwood, M.D., and colleagues of
London's Royal Brompton Hospital.
In fact, the authors suggested, it should be standard practice to give
patients an information card after they've had diagnostic or therapeutic
procedures involving radioisotopes.
The card would give:
* The date and place of the procedure.
* The radioisotope used and its half-life.
* The potential duration of radioactive emissions.
* Who to call for verification.
More than 18 million such procedures are carried out every year and more
and more radiation detectors are in place in what the U.S. Nuclear
Regulatory Commission calls "critical infrastructure," including
airports, banks, railway stations, and highway tunnels.
In 2003, the commission urged that nuclear medicine specialists make a
point of emphasizing that patients should follow the written
instructions they get after a procedure, which usually suggest not using
public transport within two days.
The recommendation came after a New York State police pulled over a bus
traveling from New York to Atlantic City after it tripped a radiation
detector in a highway tunnel leading out of the city.
It turned out that one of the passengers had received a dose of
iodine-131 earlier the same day, but had ignored her doctor's written
suggestion to avoid public transit for at least two days.
To "avoid unnecessary concern by law enforcement authorities," the
commission suggested nuclear medicine specialists should "consider"
giving patients their business card and written information about the
procedure.
A spokesman for the commission said there's no legal requirement to
report such events, so the commission doesn't know how common they are.
But reports date back to at least 1986, when a letter to the New England
Journal of Medicine noted two incidents in which Secret Service agents
seized patients who set off radiation detectors at the White House after
thallium stress tests.
The half-life of thallium-201 is 73 hours; the usual intravenous dose is
80 mega Becquerel. That means, wrote Dr. Underwood, that patients may
trigger radiation detectors for at least two weeks.
In fact, highly sensitive modern detectors -- like those issued to
police and other security personnel -- may detect the traces of
thallium-210 for as much as a month, according to a report at the 2004
meeting of the Radiological Society of North America.
The least durable radioisotope was fluorine-18, which lasted about a
day; the most durable was iodine-131, which in some cases could still
trigger detectors 95 days after it was administered.
The pilot -- who had never complained of chest pain or shortness of
breath -- was shown to have a dilated and hypertrophied left ventricle
with no evidence of inducible ischemia, the authors noted.
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