Re: Occupational vs. Medical Exposures

["David Adcock" <david@dcsmserver.med.sc.edu>]

Date sent:      	Wed, 30 Jun 1999 12:23:46 -0500 (CDT)
Send reply to:  	radsafe@romulus.ehs.uiuc.edu
From:           	"ZAPP, NEAL (JSC-SD)" <neal.zapp1@jsc.nasa.gov>
To:             	Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Subject:        	Occupational vs. Medical Exposures

I think the original question here was something like "why is so much time
and effort spent minimizing occupational radiation exposure, and yet medical
exposures apparently go unchecked?", and asked from the perspective of a
physician acquainted with radiology.  I agree with a posting I saw here that
suggested that it might have to do with the perception of a direct benefit
from the diagnostic procedure, while such a direct benefit may be lacking
for a rad worker.  I would add that this may stem from an assumption on the
part of the physicist (I will assume that this means a medical physicist
employed as part of the radiology program) that the physician knows there is
exposure involved, and that the physician wouldn't order 6 films where 2
will do, i.e. the assumption that the physician is not arbitrary in their
prescription for radiologic images.  That may or may not be the case, but it
seems to me that the decision as to whether or not a prescribed set of
images is really needed is more a medical decision than one based in
physics.  I can see there being some resistance to a physicist deciding
whether or not a patient gets the chest panel there doctor prescribed.  As
to improvement of the method and protocol for imaging (of course not limited
to x-ray imaging), that seems to be an ongoing process, but at some point we
simply must accept that using radiation as a tool for imaging means some
radiation incident on the body, and that means exposure.  Whether or not the
benefit of the exposure is outweighed by the risk is something I would think
should be decided by the patient and doctor, as again we would probably not
want to have the physicist perceived as making medical decisions.


Clearly my personal opinion

Neal Zapp
NASA/JSC, Radiation Biology

********
REPLY
*******

Thanks for your response.  The general idea was a commonly 
expressed one from physicists.

Unfortunately, most physicians have almost no competence in 
making benefit to risk decisions in situations where ionizing 
radiation is used.  The next time its convenient, ask your physician 
to estimate the population risk from a given amount of radiation.  I'll 
bet that you will not get an accurate, quantitative response.

Also, there are very large financial incentives for physicians to 
overuse (use when there is no health benefit to the patient) imaging 
procedures.  In the UK approximately half as much radiography is 
used (average per capita) as in the US but the population health 
statistics are about the same.......... so what do we get (except 
risk) for the other half of the radiation exposure, not to mention the 
large expense?

I wish things (in medical practice) were the way you seem to think 
they are but that's not the current reality.  Isn't it possible that 
medical practice decisions could be improved with input (risk 
estimates and procedural improvement) from physicists?

David

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

David Adcock, MD.MPH
University of South Carolina
Columbia, SC  29208

803 733 3295




************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html