Re: I-125 Seeds

[Gary Mansfield <mansfield2@llnl.gov>]

Linda -



The seeds are intended to reside permanently in the prostate gland.  Thus, 

in theory, only the physical half-life is operating.  It is my 

understanding however, that occasionally one or more of the roughly 100 

seeds may migrate out of the prostate, and wind up elsewhere in the body, 

or be excreted.  (From the reading I have done, it is my understanding that 

there are no adverse effects from such migration.)  So in this case there 

would be, in effect, a "biological half-time", but it would be 

unpredictable and negligible compared to the activity from the rest of the 

seeds.



Yours for early detection (guys - get your PSA tests!!!!  . . .)



Gary Mansfield

Radiation Safety Section

Hazards Control Department

LLNL



(The wild speculation expressed above does not represent the opinion of my 

employer or the agencies that pay my employer to pay me.)





At 11:58 AM 1/14/2004 -0800, you wrote:





Hi All,



I searched the archives for an answer to my question with no success, so 

here goes.  What is the typical effective half life for I-125 seeds used to 

treat prostate cancer?  Are they governed by the physical half life or is 

there biological removal involved?



Thanks,



Linda





 > Linda Sewell, CHP

 > Dosimetry Supervisor

 > Diablo Canyon Power Plant

 > MS 119/1/122

 > PO Box 56

 > Avila Beach, CA 93424

 > 805.545.4315 (voice)

 > 805.545.2618 (fax)

 > mailto:lms1@pge.com







>"RADSAFE (radsafe@list.vanderbilt.edu)" <radsafe@list.Vanderbilt.Edu>





************************************************************************

You are currently subscribed to the Radsafe mailing list. To

unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the

text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,

with no subject line. You can view the Radsafe archives at

http://www.vanderbilt.edu/radsafe/