Re: EDE from FDG

[Chris Alston <alstonc@odrge.odr.georgetown.edu>]

Karin

I advise caution in the use of the effective dose (ICRP 60). All of the
regulatory agencies, of which I'm aware, are still using the effective dose
equivalent (ICRP 26). If you had to assess a misadministration in Nuc Med, I
think that you'd want to be using the weighting factors in the regs. Beyond
that, there's simply the question of all of us being as consistent as we can
in these matters, for a host of (hopefully) obvious reasons.

chris alston
alstonc@odrge.odr.georgetown.edu

At 12:12  05/13/98 -0500, you wrote:
>Look at the 1987 ICRP Publication 53 "Radiation Dose to Patients from
>Radiopharmaceuticals"  for detailed organ and tissue doses (mGy/MBq),
>which are still accurate.  Ignore the effective dose  quoted in ICRP 53
>because it was published using the old tissue weighting factors prior to
>ICRP-60.    ICRP-62 contains an addendum to Publication 53, updating the
>effective dose (mSv/MBq) for radiopharmaceuticals, taking the new tissue
>wieghting factors into account.ICRP-62 states the effective dose from
>Tc-99m phosphates and phosphonates (used for bone imaging) to be 5.8E-03
>mSv/MBq.  The standard amount of activity given for a bone scan is 740
>MBq (20 mCi), so your effective dose from the procedure is 4.29 mSv (429
>mrem).
>
>By the way, the old ICRP-53 effective dose was higher (8.0E-03 mSv/MBq),
>which calculated out to 5.92 mSv, giving a difference of  1.63 mSv,
>depending when you underwent the procedure!!  Ain't science grand  ;-)
>
>Karin Gordon
>Radiation Safety Officer
>Health Sciences Centre
>Winnipeg, Manitoba
>KGordon@cc.UManitoba.ca
>
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