[ RadSafe ] I-131 Pt and concerns

[North, David]

As I showed in 2001 (Health Physics, September issue), the excretion of
I-131 from patients undergoing treatment for metastatic thyroid Ca is highly
variable. In my database now of well over 600 cases, there is not even any
consistency among sequential treatments given to the same patient (see
Figure 5). So, your friend-of-a-friend will NOT necessarily excrete iodine
at the same rate as anyone else.

That said, I have not studied how the administration of thyrogen will affect
I-131 excretion. If the patient is not removed from his/her hormone
replacement meds, and therefore gets thyrogen to stimulate uptake by the
metastases, there may be little effect on the patient's overall metabolism,
cardiac output, renal function, etc. Hence, the excretion may be more
consistent with that of euthyroid individuals. Perhaps Dr. Marcus or Dr.
Siegel could comment on this.

David L. North, Sc.M., DABR
Associate Physicist
Main Building, Rm 317
Rhode Island Hospital
593 Eddy St.
Providence, RI 02903
w: (401)444-5961
f: (401) 444-4446
dnorth at lifespan.org




On 1/4/12 5:43 PM, "Perle, Sandy" <sperle at mirion.com> wrote:

> Brian,
> 
> I'll send you a Power Point presentation of dose from a 26.2 mCi
> administration that includes hourly exposure after administration for about a
> week and then compares the Direct Ion Storage measured dose to TLD for
> thyroid, areas within 1 to 3 ft. from body for various areas within a home.
> For my application I was told to simply wash sheets, towels each day and wash
> them separately. For an administration of 100 to 200 mCi the dose rate will be
> higher, but the elimination from the body should be consistent with the
> graphical data I plotted.
> 
> Regards,
> 
> Sandy
> 
> -----------------------------------
> Sander C. Perle 
> President
> Mirion Technologies
> Dosimetry Services Division 
> 2652 McGaw Avenue
> Irvine, CA 92614
>  
> +1 (949) 296-2306 (Office)
> +1 (949) 296-1130 (Fax)
>  
> Mirion Technologies: http://www.mirion.com/
> "Protecting people, property and the environment"
> 
> 
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Rees, Brian G
> Sent: Wednesday, January 04, 2012 10:32 AM
> To: The International Radiation Protection (Health Physics) Mailing List
> Subject: [ RadSafe ] I-131 Pt and concerns
> 
> I have a friend, who has a friend that will soon be undergoing I-131 therapy
> for a metastasized thyroid Ca.  The Pt is a new mother, and went to the www to
> read about I-131, radiation, etc., and is now convinced she needs to throw
> away her used clothing, sleep in a different part of the house (the basement),
> and not have any contact with her baby for a month (among other things)...
> hopefully she isn't buying over-priced vitamins... but anyway...
> 
> I did go through the archives, but haven't found any what I would consider to
> be good, authoritative and informative sources of information regarding
> post-therapy care and precautions, but don't have time to go through all the
> archives either (!).  Recommendations?
> 
> I don't know how much activity they are planning to administer (assuming
> 100-200 mCi or so), or other details (she's a friend of a friend...), but one
> thing she is particularly concerned about is holding her baby at some point in
> an infant carrier (the kind that holds the baby against the chest).  Other
> than making all kinds of assumptions myself, is there an accessible program
> that I could use to calculate exposures for after a week, 2 weeks, etc., to
> help inform the mother of what doses would be, rather than having her full of
> fear?
> 
> Yes, I know it's to help the mother, and that an infant thyroid is vulnerable,
> and that her MD should be making recommendations, and that I'm not an MD,
> etc., but I sure hate to see a distorted view taken of the potential risks
> from this procedure.
> 
> Thanks in advance,
> Brian Rees, NRRPT, CHP
> 
> 
> 
> _______________________________________________
> You are currently subscribed to the RadSafe mailing list
> 
> Before posting a message to RadSafe be sure to have read and understood the
> RadSafe rules. These can be found at:
> http://health.phys.iit.edu/radsaferules.html
> 
> For information on how to subscribe or unsubscribe and other settings visit:
> http://health.phys.iit.edu
> _______________________________________________
> You are currently subscribed to the RadSafe mailing list
> 
> Before posting a message to RadSafe be sure to have read and understood the
> RadSafe rules. These can be found at:
> http://health.phys.iit.edu/radsaferules.html
> 
> For information on how to subscribe or unsubscribe and other settings visit:
> http://health.phys.iit.edu