Re: Radioactive Sentinel Lymph Node Biopsy Handling

From:"Dr. Allen A. Smith" <asmith@mail.barry.edu>

    Tc is technetium.  The isotope used in medicine is technetium-99m, which
has a half-life of 6 hours.  If the technetium-99m had been the patient as
little as 2 days, only 1/4 of 1% of the original radioactivity would be
left.  If the technetium-99m  had been in the patient for a week, less than
one millionth of 1% of the original radioactivity would remain.
    Technetium-99m decays to technetium 99, which slowly decays (200,000
year half-life) by emitting low-energy beta radiation.  Little, if any, of
it would get beyond the deeper layers of your skin.  It's unlikely to do
your skin much harm in the few hours that you'd be exposed to it while
grossing, embedding, and sectioning.  The usual precautions against getting
it into your digestive or respiratory tract (where it would remain for much
longer) are essential.  If you spend a lot of time near (less than 15 feet
from) the cabinet where the slides are stored, make sure the cabinet is
metal (or very thick plastic).  1/32 inch of steel (or 1/4 inch of plastic)
should be sufficient to stop low energy beta rays.

Allen A. Smith, Ph.D.
School of Graduate Medical Sciences
   Podiatric Medicine and Surgery
Barry University
Miami Shores, Florida
----- Original Message -----
From: Joe Nocito <jnocito@email.com>
To: <DCarlton@samhealth.org>; HistoNet <HistoNet@pathology.swmed.edu>
Sent: Friday, August 03, 2001 7:18 PM
Subject: Re: Sentinel Lymph Node Biopsy Specimen Handling


> Donna,
> what type of isotope is being used?  At my last place of employment, we
were told by radiation saftey that we could gross the specimen as soon as we
eceived it.  I don't remember the name of the isotope, but the abbreviation
was Tc.
>
>
> Joe Nocito, BS, HT (ASCP) QIHC
> Histology Manager
> Pathology Reference Laboratory
> San Antonio, Texas
> jnocito@email.com
> -----Original Message-----
> From: Donna Carlton <DCarlton@samhealth.org>
> Date: Fri, 03 Aug 2001 10:23:32 -0700
> To: "'HistoNet'" <HistoNet@pathology.swmed.edu>
> Subject: Sentinel Lymph Node Biopsy Specimen Handling
>
>
> Re: This is my first time to present a question on Histonet.  I am in a
clinical
> Re: setting.
> Re:
> Re: I am interested in information regarding radioactivity used in the
lymph
> Re: node procedure for breast tissue.  I have been assured by radiology
that the
> Re: hazard after 24 hours is minimal.
> Re:
> Re: Does anyone have a procedure/protocol that they are willing to share
on
> Re: this?
> Re:
> Re:
>
>
>
> --
>
>
> Joe Nocito, BS, HT (ASCP) QIHC
> Histology Manager
> Pathology Reference Laboratory
> San Antonio, Texas
> jnocito@email.com


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