Re: Dose to others from medical uses of radioactivity, and a PS on

["John Saunderson" <johnsaunderson@hotmail.com>]

Patients treated for thyrotoxicosis (i.e. overactive thyroid gland) are
given between 100-500 MBq ( 3-14 mCi) of I-131 in order to effectively kill
off part of the gland. In the UK, these patients are advised not to travel
by public transport for a limited period if they have been administered over
400 MBq (11 mCi)

The dose rate at 1 m from a patient administed with 400 MBq of I-131 will
typically be around 20 micro-Gy/h, i.e about 0.6 mrad/h at 6 feet

Patients with thyroid cancer are often treated with much larger doses,
typically 3-8 GBq (80-200 mCi) in order to destroy the whole of the
cancerous thyroid plus any secondary tumour cells that may have spread to
other parts of the body. These patients are isolated in a dedicated room for
several days until the level of activity has decreased sufficiently for them
to be allowed home.



John Saunderson
Radiation Physics Department
The Princess Royal Hospital
Hull
UK
johnsaunderson@hotmail.com


----- Original Message -----
From: <Jacques.Read@eh.doe.gov>
To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Sent: Thursday, February 10, 2000 4:51 PM
Subject: Dose to others from medical uses of radioactivity, and a PS on


>
>
> A colleague  has been carrying a pocket alarm/dosimeter around for years,
> visiting various DOE facilities.  It has never alarmed.  While traveling,
he
> keeps it in his briefcase.  While awaiting a flight at a regional airport
> recently, the alarm went off in his briefcase whenever a elderly gentleman
> walked by.  I compared his experience with the RADSAFE discussion a week
or so
> ago about misadministration of 131I, in which 500 microcuries had been
injected
> instead of 100 microcuries.  By my rough estimate, 500 microcuries would
given a
> dose rate of only 0.03 mr/hr at six feet.  Presumably the gentleman was
not a
> thyroid patient.  Did I botch up my dose rate estimate, and are there
other
> medical procedures that could give tens of mr/hr at six feet?
>
> P.S.  To answer Al's question: The depleted uranium from the Paducah
gaseous
> diffusion plant is believed to have been contaminated by the use of
improperly
> decontaminated steel storage cyclinders to receive the UF6 from the
product end
> of the cascade.  The DU has typical Pu content of the order of  0.01 to
0.001
> Becquerels per gram of uranium.  The cyclinders had previously contained
> recycled uranium of a few parts per billion Pu content.
>
> Jacques Read
> jacques.read@eh.doe.gov
>
>
>
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