RE: Thalium Stress Test

["dale" <dboyce@intiso.com>]

The Dr. wants to rule out angina caused by cardiac ischemia.  The non-rad
techniques have a much higher false negative than the rad techniques.  Many
hospitals use Tc99m labeled to a cold kit which results in faster decay to
background.  F-18 FDG can also be used, but the cameras equipped for F-18
are not as common.

If I remember the numbers accurately, a cardiologist at a former employer
quoted echo cardiograms as giving something like a 20% false negative i.e.
about 1 in five patients undergoing echo later demonstrated ischemia either
through a nuc med technique or cardiac problems.  Of course this depends on
the quality of the initial screening.  A Dr. that overprescribes echo would
have a lower false negative.  The number I remember for false negatives with
nuc med procedures was 3%.

The Doc may have reasons that he didn't share for wanting the stress test.
Either have the test or get a second opinion, but don't second guess.  The
whole body exposure won't be more than a few hundred mrem. A year or two
background exposure.

Dale Boyce
International Isotopes
dboyce@intiso.com

-----Original Message-----
From: GRAHNK@aol.com [mailto:GRAHNK@aol.com]
Sent: Monday, January 08, 2001 10:23 AM
To: Multiple recipients of list
Subject: Thalium Stress Test


OK,
Here's one for all you medical folks out there.  One of my people (40
year
old male) had a 3 week bout with pneumonia last year.  This year when
exposed
to cold outside air (0 degrees and below) he has experienced some
central
(sternum) chest pain that goes away when he doesn't breathe the cold
air.  He
doesn't have any history or family history of cardiac illness.

His family practice physician (not a cardiologist) has ordered a thalium

stress test.  He's been asking me and we're both wondering why?  It's
not
clear what the doc is looking for.

Does this make sense from an ALARA perspective?  Is there an alternate
diagnostic procedure that doesn't involve radioactive material?  i.e.
echo or
stress echo

If he proceeds with this procedure what might his expected dose be?

Thanks

Kelly Grahn
Illinois Department of Nuclear Safety
West Chicago Field Office

grahnk@aol.com
or
grahn@idns.state.il.us
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