MDL and Dose Effects

[Kent Lambert <lambert@allegheny.edu>]

H.Wade Patterson wrote:

> This "regulatory construct" is an example of why ALARA is useless. On
> the one hand we spend untold time, money, and effort on ALARA in the
> laboratory and institution, and nothing at all on ALARA where the doses
> are the greatest, the medical field.

Really.  I thought diagnostic medical physics evaluated fluoroscopic and 
radiographic equipment to assure that it was properly filtered (to reduce 
entrance:film exposures), that the film alignment systems were operating 
properly (so that only the intended parts of the body are exposed), that film 
processing equipment operates properly (to reduce unnecessary film retakes), 
that timers operate correctly, that kVp settings are accurate, that mA or mAs 
settings are linear wrt exposure, that output are within specifications, and 
other tests to reduce exposures and increase the diagnostic benefit.

Further, ALARA is (or should be) more than $$$/person-dose saved.  It must 
have a benefit component as well.  How many rad are acceptable to save a 
life?  To correctly diagnose a serious ailment?  Or even evaluate conditions 
to prevent serious ailments?  Just because goals are not set and records 
maintained does not mean that ALARA is not practiced.  Further, in your 
example (in response to D. Scherer, you have picked an example where major 
efforts have been made to reduce patient doses (NEXT or was it DEXT?).  I 
suggest reading 'Hosptial Health Physics: Proceedings of the 1993 HPS Summer 
School' pages 45-52.  The abstract to this chapter by KL Miller is as 
follows:  
   "The ALARA principle applies to patients as well as the radiation worker. 
In diagnostic radiology, keeping exposures low for the patient will aid in 
keeping the exposures low for the radiation worker.  In order to accomplish 
this, routine testing and evaluation of equipment and procedures, personnel 
monitoring and continuing education are of paramount importance." 

Just because the NRC does not have jurisdiction over these medical uses does 
not mean that there are not controls. (Is this a triple negative?)  The Joint 
Commission for the Accreditation of Health Care Organizations (JCAHO) 
inspects hospitals routinely.  Loss of accreditation means third party payers 
don't pay.  Then the hospital goes bankrupt.  So, who has more power, fed and 
state regulators or JCAHO?

With that said, shouldn't we (and I mean you, me, and the HPS) be lobbying to 
increase our presence in medical school curricula if we really want to reduce 
diagnostic radiation doses?

On the other hand, if hormesis is true then diagnostic radiation medicine is 
doubly benefitial.  Uh-oh, I can see this thread digressing now.

-- 
Kent Lambert, CHP
lambert@allegheny.edu

All opinions are well reasoned and insightful.
Needless to say, they are not [necessarily] the
opinions of my employer. - paraphrased from Michael Feldman