RE: I-131 therapy capsules

["North, David" <DNorth@Lifespan.org>]

Our physicians administer the I-131 dose in liquid form only very rarely,
say to a pediatric patient who doesn't swallow capsules well. A long time
ago, probably before the capsules got better, I remember a case or two when
a patient didn't digest the capsule and it was found in a bedpan the next
day.

Years ago I somehow got a small quantity of liquid I-131 on the skin of my
finger, about 8 mCi. I know that because I stuck my finger into a dose
calibrator in the nuclear medicine department and saw that reading. I
immediately washed my hands very thoroughly with Betadine iodinated surgical
scrub, which is notorious (along with iodinated x-ray contrast media) for
interfering with diagnostic nuclear medicine thyroid exams. A check of my
thyroid the following day revealed no uptake. I'm sure that without the
blocking by the Betadine I would have accumulated some uptake. Stabilized or
not, I-131 is readily absorbed through the skin, so a bioassay is definitely
indicated.

David L. North, Sc.M. DABR
Associate Physicist
Department of Medical Physics
Rhode Island Hospital
593 Eddy St.
Providence, RI 02903
ph: (401)444-5961
fax: (401)444-4446
dnorth@lifespan.org


> ----------
> From: 	Dave Derenzo
> Reply To: 	radsafe@romulus.ehs.uiuc.edu
> Sent: 	Monday, April 24, 2000 10:07
> To: 	Multiple recipients of list
> Subject: 	RE: I-131 therapy capsules
> 
> Since we are still on the subject of I-131 therapy capsules, I have heard 
> that there are two reasons why some physicians prefer to administer the 
> solution:
> 
> 1.  It is much easier to specify a custom dose
> 
> 2.  A small spot in the stomach of the patient who gets a capsule can 
> receive a high dose before and while the capsule is dissolving.  An
> attempt 
> to mitigate this dose is usually performed by having the patient drinking
> a 
> lot of water.  In contrast, the solution mixes readily with stomach
> contents.
> 
> Also, with regard to thyroid bioassays, what happens if a person involved 
> with administering the stabilized liquid gets some on his or her 
> skin?  Will it absorb?  If so, do you feel that a bioassay would then be 
> needed?
> 
> All comments are welcome and I promise not to flame anyone for their 
> opinion.  Others please follow suit.
> 
> Dave Derenzo
> 
> At 07:42 AM 04/24/2000 -0500, you wrote:
> >Does the tech who administers the sample continue with some follow-up on
> the
> >patient?
> >
> >We had an HP tech visit his mother in the hospital, not a nuclear
> medicine
> >patient.  He came back with I-131 (~100 mREM CDE).  Yes, less than 10% of
> >the limit (50 REM) requiring monitoring, but throw a few of these into
> the
> >mix and some #s begin to add up.
> >
> >One needs to look at the annual picture when deciding not to monitor.
> >
> >Matt Williamson
> >Indian Point Unit 3
> >Williamson.m@nypa.gov <mailto:Williamson.m@nypa.gov>
> >
> >************************************************************************
> >The RADSAFE Frequently Asked Questions list, archives and subscription
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> 
> Dave Derenzo, RSO (dave@uic.edu)
> UIC Radiation Safety Section, M/C 932
> Phones: Voice (312) 996-1177  Fax: (312) 996-8776
> 
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> The RADSAFE Frequently Asked Questions list, archives and subscription
> information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
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