Re: radiopharmaceutical patient release

[JMUCKERHEIDE@delphi.com]

Thanks, Kent. I stand corrected. I suppose the idea of "no effect" would be
somewhat a conflict for a "therapeutic" application :-)  I'll stipulate that
we are only discussing  carcinogenic effects (though molecular and cellular
biology has established that this is not a "stochastic" process); and for
patients for whom their condition does not confound the assessment of late
cancer (and other latent health effects).  

Regards, Jim

> JMUCKERHEIDE@delphi.com wrote:
> 
> > If the patient is at essentially no risk with the material in them, why would
> > a rational person consider that the much lower dose to others is significant?
> > (excusing the practioner or another party who is continuously exposed to many
> > patients and procedures).
> 
> There are clearly non-stochastic effects from the administration of
> 20-30 mCi of I-131 to patients (doses for treating hyperthyroidism). 
> There are clearly non-stochastic effects from the administration 4 mCi
> of Sr-89 for bone pain.  There are clearly non-stochastic effects from
> the administration of I-125 as a permanent implant to treat interstitial
> cancer.  Therefore, the "if" of your 'If/then" argument is not valid for
> therapeutic administrations.  
> 
> If a patient is treated as a outpatient for Graves disease, gets on an
> airplane, and gets airsick, then a significant amount of I-131 can be in
> the vomitus.  I have measured 1 mCi out (of a 150 mCi administration) in
> the vomitus from a patient that got sick 8 hours post administration. 
> What's the dose rate to the skin from this?  Assuming 1 mCi on 100 cm^2
> it's 63 rad/h of contact time.  That results in erythema in 5 hours of
> contact time.  Without instructions, how is someone to know that careful
> and prompt washing (or removal of contaminated cloting) is important?
> 
>  
> --
> Kent N. Lambert, CHP
> lambert@allegheny.edu
> 
> My employer takes no credit for opinions
> expressed by this writer.