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Re: Radiation to the breast is hormetic at 0.15 Gy
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>Date: Thu, 12 Feb 1998 09:12:43 -0800
>Reply-To: lcbaird2@worldnet.att.net
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>From: "L.C. BAIRD" <lcbaird2@WORLDNET.ATT.NET>
>Subject: Re: Radiation to the breast is hormetic at 0.15 Gy- feel free
>To: Multiple recipients of list MEDPHYS <MEDPHYS@LISTS.WAYNE.EDU>
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>Since hormesis is on the table again, I might mention the phenomenon of
>thermal hormesis. About 15 years ago one of my sons brought home the
>dreaded announcement that he needed a science fair project for his school.
>I suggested that he dip wheat seeds in boiling water for various amounts of
>time & measure the effect on viability. As expected, he found that boiling
>wheat seeds for 20-30 minutes makes great oatmeal (wheatmeal?), but totally
>destroys viability. As the boiling time was reduced, palatability went down
>accordingly and some seeds were able to germinate. But, surprisingly,
>viability peaked at about 1(?) minute of boiling, not 0 minutes of boiling.
>There you have it, thermal hormesis!
>
>L.C.Baird, Ph.D.
>ACURAD SYSTEMS, INC.
>BRANDON, FL
>lcbaird2@worldnet.att.net
>
>
>
>----------
>: From: JOHN CAMERON <jrcamero@FACSTAFF.WISC.EDU>
>: To: Multiple recipients of list MEDPHYS <MEDPHYS@cwis-20.wayne.edu>
>: Subject: Radiation to the breast is hormetic at 0.15 Gy- feel free
>deletewithout reading!
>: Date: Wednesday, February 11, 1998 1:48 PM
>:
>:
>: ** Mail from Medphys Listserver **
>: If you reply to this message, it will be posted on Medphys for all the
>: subscribers to review ...
>:
>:
>: Dear Colleagues, I haven't read the NCRP Report No. 85 but I am somewhat
>: familiar with the Canadian study of breast cancer reported by Miller et
>al
>: in the N. Engl. J. Medicine 1989: 321; 1285-1289. That shows data to
>: indicate an increase of breast cancer for doses at 0.35 and 0.55 Gy.with
>a
>: RR of 1.2/Gy However at 0.15 Gy the breast cancer incidence is reduced
>: about 35% from the unirradiated controls. It is statistically significant
>: at the 95% confidence level. The breast cancer incidence at 0.25 Gy is a
>: lower than for the controls but only about at one std. dev.
>: These data from low level have been excluded from published
>reports
>: because "everyone knows that radiation doesn't reduce cancer."
>: The discussion of risks from mammography should mention real
>data
>: rather than base risk on the LNT model which has no support at doses
>below
>: about 0.2 Gy.
>: The above data is from an article by Myron Pollycove, MD "THE
>RISE
>: AND FALL OF THE LINEAR NO-THRESHOLD (LNT) THEORY OF RADIATION
>: CARCINOGENESIS soon to be published in the Physics & Society News
>: Another related article by LE Feinendegen, Victor Bond & Chas.
>: Sondhaus LOW LEVEL RADIATION MAY PREVENT CANCER describes four cellular
>: mechanisms that are protective against cancer below about 0.2 Gy (acute).
>: It will be published in the same issue of P&S News. If you can't wait I
>: can provide a pre-print copy of either article by mail. (By the way, the
>: data from the last article is the reason that I would be comfortable
>: getting up to 1 Gy per year if it didn't exceed 0.1 Gy at any one time.
>In
>: case you saw the summary of Walter Huda's survey recently I submitted the
>1
>: Gy/y value and gave my reason. - I had no political motivation. )
>: It would be fair to explain to women having mammograms that the
>: radiation dose is likely to reduce the risk of breast cancer! By the way
>: how do medical physicists suggest that radiologists or RTs explain the
>risk
>: from a mammogram (or any other exposure). Last year when my wife asked
>the
>: RT how much radiation she would receive for her mammogram, the RT
>responded
>: "enough to do the job!" When I wrote the radiologist asking for the dose
>: from the mammogram and from a lower GI series she had from the same
>: radiological group, I never received an answer! (I wasn't concerned - I
>was
>: curious how they would respond.)
>: Physicists should consider it part of the physics education of
>: radiologists to present information on how to explain radiation to
>: patients. If anyone is interested I will send via e-mail my article
>: EXPLAINING RADIATION TO PATIENTS submitted to Applied Radiology about a
>: month ago.
>: A major factor for women to refuse mammograms these days is
>: because of the pain from the compression. I notice in the recent AAPM
>: Newsletter that the compressional force is 25 to 40 lb. That is not
>: trivial. Think of that compression force on any of your delicate
>tissues!
>: I think it would be useful to go back to xeromammograms where such force
>is
>: not necessary and the larger dose to the breast would further reduce the
>: risk of breast cancer if it didn't exceed 0.15 Gy!
>: It is unscientific to base risk from mammograms on the LNT model
>no
>: matter how you calculate the dose. I wonder how many medical physicists
>: believe in the LNT model of radiation carcinogenesis.
>:
>: Wlad wrote:
>: >Still, I tend to like Walter's argument. Here is why. To me, the main
>: >reason we calculate the dose to the breast is to assess the risk of
>: >inducing cancer as a result of irradiation. Clearly, the probability of
>: >inducing cancer scales with the irradiated volume. So, the risk for the
>: >woman that got diagnostic (whole breast) dose of 150 mrad will actually
>be
>: >larger than the risk for the woman that got 300 mrad to 1/4 of the
>breast
>: >volume during biopsy procedure. I think both women should know that.
>: >Wlad
>:
>: I think they should be told that there are no data to show any risk at
>: these low doses. What data exists from the Canadian study shows a
>reduction
>: of risk! Why scare them with non-existant data! John
>:
>:
>: John R. Cameron, winter home: 2678 SW 14th Dr., Gainesville, FL 32608
>: phones : 352/371-9865; Fax 352/371-9866 About May 15, 1998 we go to our
>: summer home: 2571 Porter Rd., P.O. Box 405, Lone Rock, WI 53556-0405
>: Phones: 608/583-2160; Fax: 608/583-2269 e-mail all year:
>: jrcamero@facstaff.wisc.edu
>