Hormesis - medical benefits?

[FIELDRW@aol.com]

Mark, 

I think we have to be careful when we generalize that "demonstrable medical 
benefits" were seen with a specific dose.  What were these medical benefits.  
How do you know that there were also not short-term or potential long-term 
adverse effects.

In some cases, much higher doses are given than 150 rad to produce 
"demonstrable medical benefits."  

For example, the following paper:

Strober,Tanay, Field, Hoppe, Calin, Engleman, Kotzin, Brown, and Kaplan, 
Efficacy of total lymphoid irradiation in intractable rheumatoid arthritis. A 
double-blind, randomized trial., Annals of Internal Medicine. 102(4):441-9, 
1985.

Abstract 
Twenty-six patients participated in a randomized, double-blind study of the 
efficacy of total lymphoid irradiation in the treatment of intractable 
rheumatoid arthritis. All 26 patients, for whom therapy with gold compounds 
and penicillamine had failed, would ordinarily have been considered 
candidates for cytotoxic or antimetabolite drug therapy. Thirteen patients 
randomly assigned to receive full-dose total lymphoid irradiation (2000 rad) 
and 11 patients assigned to receive control low-dose total lymphoid 
irradiation (200 rad) completed radiotherapy. Alleviation of joint disease 
activity was significantly greater in the high-dose group as judged by 
morning stiffness, joint tenderness, and functional assessment (global 
composite score) at 3 and 6 months after radiotherapy. The high-dose group 
had a marked reduction in both T-lymphocyte function and numbers, but this 
finding was not observed in the low-dose group. Complications seen in the 
high-dose but not low-dose group included transient neutropenia, 
thrombocytopenia, pericarditis, and pleurisy.    

The demonstrable medical benefit in this cases was the reduction in the 
patient's arthritic symptoms.  Is there a potential for an adverse effect?  
You bet.

My only point is that I don't think we should be to quick to put all our eggs 
in a single "hormesis basket" (isolated findings), without examining more 
indicators of the overall long term medical benefits.  All of these factors 
need considered to determine the risk versus benefit of any treatment.

A side note, in this case the 200 rad was the control.  It would be 
interesting to see if the researchers compared the immune function of their 
"controls" to the immune function of a cohort of non-exposed rheumatoid 
arthritis patients.


Bill Field
Department of Epidemiology
College of Public Health
Iowa City, IA

bill-field@uiowa.edu


In a message dated 1/26/00 12:07:06 PM Central Standard Time, MRotman@snm.org 
writes:

<< Demonstratable medical benefits of low dose/low dose rate radiation have
 been seen using 150 rads (either whole or half body) given in 10 to 15
 fractions over 5 weeks.  This has been done in Japan and in the US.  This
 dose appears to be optimal for immune system stimulation creating an
 approximate 160% improvement in function.  Interestingly enough it appears
 the spleen is the organ critical to success.  
 
 As a nuclear pharmacist by training I prefer to think of using a long acting
 radiopharmaceutical, one that is naturally concentrated in the spleen.
 Perhaps Fe-59 as transferrin, or as labeled red blood cells.
 
 Way back in '92, while a Medical Visiting Fellow at the NRC, I imagine folks
 suing the NRC because their regs were depriving folks of medically necessary
 radiation....
 
 Yes, the regulatory landscape will undergo a paradigm shift when hormesis is
 finally accepted as the truth.
 
 
 
 Mark Rotman
 Government Relations
 Society of Nuclear Medicine
 703-708-9000 ext 1242
 703-708-9777 FAX
 mrotman@snm.org
 http://www.snm.org >>
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