[ RadSafe ] FW: Outpatient I-131 Therapy under attack

[alstonchris at netscape.net]

Folks

I would only add to David's nice summation, and caveat, that the doserate does not remain constant but decreases relatively rapidly over nominally the four or five days immediately following treatment.  Also, most pts, and especially nowadays, when thyroid Ca is often caught at a very early stage, have very low uptake.  Three percent is a good nominal figure for that.


Cheers 
cja



-----Original Message-----
From: North, David <DNorth at Lifespan.org>
To: radsafe at agni.phys.iit.edu
Sent: Tue, Mar 23, 2010 11:56 am
Subject: [ RadSafe ] FW: Outpatient I-131 Therapy under attack



>From our experience of over 700 in-patients and 600 out-patients, we have
easured about 0.17 mR/hr/mCi at one meter after administration. That works
ut to about 1.63 mR/hr at 15 feet from 200 mCi, and therefore about 13 mR
n 8 hours. The caution is that the exposure rate per mCi among a bunch of
atients can vary by a factor of 2 either way.
David L. North, Sc.M. DABR
edical Physics
ain Bldg. Rm 317
hode Island Hospital
93 Eddy St.
rovidence, RI 02903
401)444-5961
north at lifespan.org

On 3/18/10 9:53 PM, "Steven Dapra" <sjd at swcp.com> wrote:
> March 18
 
              More whining (in USA Today article) about the danger to
 children.  How many I-131 patients are around children, and for how long?
 
            Assuming that Peter Crane's 200 milliC is true, at an
 average distance of 15 feet, how many millirems would someone receive
 in eight hours?