Re: Tc-99m Bioassay in Nuclear Medicine Workers

[Karin Gordon <kgordon@cc.UManitoba.CA>]

Dear Richard

My colleague Dr. Merv. Billinghurst (head of our centralized radiopharmacy) and I 
(RSO) are just finishing up a national research project in Canada(funded by the Atomic 
Energy Control Board) to identify suitable detector systems and then to determine the 
frequency and magnitude of Tc-99m contamination in Nuclear Medicine workers. We 
performed a formal evaluation of many types of radiation detectors and counting 
geometries.  We then placed our custom designed bioassay system in 20 different 
hospitals across Canada, where all nuclear medicine & radiopharmacy staff submitted to 
daily bioassay measurements for 6 months, and also kept track of the amount of Tc-99m 
they handled, and the types of procedures performed.  We are currently in the process of 
analyzing the results of many thousands of daily Tc-99m bioassay measurements on these 
volunteers, selecting dosimetry models, estimating the effective radiation doses to 
those who did show intake of Tc-99m, and finally correlating the results (intakes, 
committed effective doses) to the type of work they were doing. The AECB supported this 
research project in order to determine if and when Tc-99m bioassay measurements should 
be required to ascertain internal doses. 

This was a major project, which has kept us very busy over the past 4 years.  We are in 
the process of writing up our fimal results and will submit several papers on the topic 
for publication in a few months. 

I will present our findings at the May 1997 Conjoint Meeting of the Canadian Radiation 
Protection Association and the Campus Radiation Safety Officers to be held in Victoria - 
see the January HPS Newsletter (p.23) for details if you plan to go.  

I caution you that a simple daily frisk (as suggested by another Radsafer) will not give 
very meaningful information - we spent a year evaluating different types of detectors  
and designing our bioassay system & phantom.  So I'd suggest that you and anyone else 
who is interested just wait for about six months until our results are published - or 
attend the conference.  

Karin Gordon
Radiation Safety Office
Health Sciences Centre 		phone	(204) 787-2903
GC-214, 820 Sherbrook St.	fax	(204) 787-1313
Winnipeg, Manitoba, Canada	e-mail	kgordon@cc.umanitoba.ca
   



Richard Wu wrote:
> 
> Dear Radsafe:
> 
> I wonder how to document the internal dose in a
> Nuclear Medicine Department. Specificly, how to do the
> bioassay to monitor the Tc-99m intake. Thanks for any
> advise.
> 
> -------------------------------------
> Name: Richard Wu,MS,DABR,DABSNM
>       Radiation Safety Officer/Diagnostic Physicist
>       United/Unity/Mercy Hospital
>       St. Paul, MN 55102
> 
> E-mail: Richard Wu <wu@allina.com>
> Date: 1/22/97
> Time: 10:49:04 AM
> 
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