Re: Radioactive blood

[Richard Smart <R.Smart@unsw.edu.au>]

Radsafers,

I agree completely with Carol Marcus.  It should not be necessary to draw
blood from a patient being treated with I-131, except in an emergency
situation.

However the original request related to ALL nuclear medicine patients, not
just those receiving therapy.  The only concern with blood from patients
who have had diagnostic nuclear medicine studies is possible interference
with the results of pathology studies, if these are performed using RIA.

Regards

Richard

At 01:05 P 1.12.1999 -0600, Carol Marcus wrote:
>At 11:56 AM 12/1/99 -0600, you wrote:
>>>We have had a few I-131 patients who had to have blood drawn during their
>>>hospital stay.  Sometimes the blood is drwan within a few hours of I-131
>>>administration.  We found that this blood can be quite hot.  To the point
>>>that I didn't like handling it without a lead container (approx 10-20 mR/hr
>>>at the test tube surface, where the phlebotomist and lab personnel will be
>>>handling it).  In spite of this, the bigger concern was when the lab
disposed
>>>of the contaminated blood.  I-131 has some fairly energetic photons that
will
>>>be picked up by the radiation detectors at the medical waste incenerator
even
>>>in small quantities (on the order of 1 or 2 millicuries.  Don't ask how I
>>>know!).
>>>
>>>So really the bigger question here is maintaining control of the
radioactive
>>>materials used under your license.  The previous RSO was probably only
>>>concerned with exposure to personnel but, with the strict precautions, he
>>>also took care of the control issue.  I would recommend that you move
>>>carefully in removing some of these controls.  We instituted the rule
that if
>>>blood (or any other bodily fluid) was to be removed from the restricted
area,
>>>a physicist MUST be present to oversee the process.  We would survey the
>>>sample after it was taken and then walk it through the lab if there was a
>>>significant reading coming off of it.  Yes, this meant that I was called at
>>>one or two in the morning and had to go in to oversee the blood, but on
>>>almost every occasion I was glad that I did!  This should go for other
>>>isotopes that give off gammas as well.  We didn't worry about Metastron,
>>>since it is a pure beta emitter.  We did worry about Quadromet since Sm-153
>>>has a 103 keV (or there abouts) gamma that is easily detectable a good
>>>distance away.
>>>
>>>Just my two cents worth and I will say that I tend to the cautious side on
>>>these issues, so meet your own comfort level.
>>>
>>>Charles M. Carver, MS, DABMP
>>>Chief Physicist
>>>Medical X-ray Center
>>>Sioux Falls, SD
>>>ccarverms@aol.com
>>************************************************************************
>>The RADSAFE Frequently Asked Questions list, archives and subscription
>>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
>>
>
>
>Dear All:
>
>In 19 years of Nuclear Medicine practice, I have never found it necessary to
>draw blood shortly after I-131 was administered.  All bloods were drawn
>ahead of time.  The first question to ask is why these bloods were being
>drawn in the first place.
>
>The Authorized User is responsible for all aspects of this, not a physicist.
>You should not be coming in to worry about it---your AU should.  And, if he
>is too irresponsible to do so, he shouldn't be an AU.  If your patient is
>that sick, the AU had better be there or be directing things from wherever
>he is.
>
>The Quadramet situation is different, in that it clears much more quickly
>from the blood than NaI-131.  By 6 hours post-administration, all Quadramet
>has either gone to the skeleton or has gone out in urine; only trace amounts
>remain in the blood. The photon is only present in 29% of disintegrations,
>and activity administered is usually 70 - 100 mCi.  
>
>Ciao, Carol
>
>************************************************************************
>The RADSAFE Frequently Asked Questions list, archives and subscription
>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
>
>
>
Richard Smart PhD
Principal Physicist & Radiation Safety Officer
Department of Nuclear Medicine
St. George Hospital
Kogarah, NSW 2217
Australia
Tel:61 2 9350 3112
Fax:61 2 9350 3991
Email:R.Smart@unsw.edu.au
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html