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

["Langenegger, Armin" <alang@allsaintshealthcare.org>]

In my institution, we perform prostate implants with both Iodine-125 seeds
and Palladium-103 seeds. The NRC allowed release exposure rates are defined
at 1 meter and are 0.96 mR/hr and 4.3 mR/hr respectively. This will give
members of the general public up to a one time exposure (allowed under NRC
regulations) of 500 mR. These patients are then allowed to travel by plane,
bus, go to work etc etc, and the calculations we perform, assume a 25%
contact time for other individuals, including spouses.

In addition there are other "Permanent Implants" that can be done eg. Au198
which would allow higher exposure rates (shorter lifetime), but this isotope
is very rarely used these days for any implants.

The other avenue, as other members have stated, is thyroid ablations and
bone scans. These patients are also allowed to leave the hospital at certain
exposure levels.

The rules were I believe changed due to the influence of HMO's requiring
fewer hospital stays (carol can correct me).

Armin Langenegger MS DABMP






		-----Original Message-----
		From:	Jacques.Read@eh.doe.gov
[mailto:Jacques.Read@eh.doe.gov]
		Sent:	Thursday, February 10, 2000 10:51 AM
		To:	Multiple recipients of list
		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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