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Re: medical misadministration to child
At 01:28 PM 4/4/03 -0600, Michael G. Stabin wrote:
>Two technical problems here:
>
> > From: "William V Lipton"
> > Thus, the dose estimate would be:
> > (5.72 E-3 mrem/pCi)*(400 uCi)*(1 E6 pCi/uCi) = 2.3 E6 mrems = 2300 rems
>
>At this level, dose equivalent has no scientific meaning, one should report
>absorbed dose (Gy preferably, or rad in antediluvian units). Also, "Sv" and
>"rem" are already plural, in my understanding.
>
>There are more up-to-date and detailed dose estimates in ICRP 53 for the
>10-year-old for I-131 NaI of:
>
>790 mGy/MBq at 35% uptake
>1500 mGy/MBq at 45% uptake
>1900 mGy/MBq at 55% uptake
>
>which would suggest doses of 11700, 22000, or 28000 mGy (1170, 2200, or 2800
>rad). That's pretty good agreement with the older Reg Guide numbers.
>Hyperthyroid individuals will have higher uptakes than euthyroid
>individuals, but generally with faster washout. I have not seen a well
>characterized kinetic model for I-131 NaI in hyperthryoid children, so it's
>hard to get much more accurate with the dosimetry.
>
> > The nonstochastic occupational limit for a minor would be 5 rems. It
> > seems like the patient could expect a "significant adverse" health
> > effect.
>
>We know that the nonstochastic occupational limit of 500 mGy is pretty low
>for most organs, where a threshold of 10's of Gy are needed to show a
>nonstochastic effect (as per experience with radiation therapy). The testes
>can show transient effects at the 500 mGy level, so we set it this low for
>all organs. It is not reasonable to expect a nonstochastic effect at 51 mSv
>(5.1 rem) because we have set an administrative level of 50 mSv (5 rem), 10
>times lower than the low numbers for adults. Children may be more
>radiosensitive, but this low level is based on administrative concerns, not
>radiobiology. Dr. Marcus can probably enlighten us about what, if any,
>nonstochastic effects might be expected from these doses.
>
>Mike
>
>Michael G. Stabin, PhD, CHP
>Assistant Professor of Radiology and Radiological Sciences
>Department of Radiology and Radiological Sciences
>Vanderbilt University
>1161 21st Avenue South
>Nashville, TN 37232-2675
>Phone (615) 343-0068
>Fax (615) 322-3764
>Pager (615) 835-5153
>e-mail michael.g.stabin@vanderbilt.edu
>internet www.doseinfo-radar.com
>
>
>
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Dear Mike et al.:
I would expect no effects at all.
Ciao, Carol