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RE: Radioactive "seed" treatment no threat to others- ISOTOPE??
Dr. Farber,
I worked at Lawrence Soft Ray in 1978, Donald Lawrence developed the seeds
and founded the company to manufacture them. Shortly after I joined, [3
days] the sale to 3M was completed.
I-125 has a gamma at about 8 or 9% incidence that has an energy of 35 keV
and tellurium x-rays. The K shell x-rays range in energy from 27 to 31 keV.
For gamma, very non-penetrating. 1 cm of water should attenuate it by about
15%.
They may have been the first to put dosimetry on members of the family but
any decent HP would survey the patient and realize there was little problem.
"We can now tell a woman, 'The amount of radiation you will get from your
husband in one year is less than you would get from living in Denver for
three or four months,'"
Like nobody had any idea before this? I am sure many HPs and MDs have
provided similar assurances to many wives for the 20 - 25 years the I-125
Seeds have been in use. It would only be necessary to use a low energy
capable ion chamber such as the Victoreen panoramic, the one with the Dixie
cup chamber, to see how little radiation was getting out of the patient.
BTW the half life is 60 days which means that they do not usually have to be
removed. They are implanted, as the tumor shrinks it acts against the
decay, increasing the dose to the tumor while decay decreases it.
I guess I would characterize the article/report as "Much to do about
[almost] nothing."
Any opinions expressed are mine alone and do not necessarily represent
those of the Denver VA Medical Center, The Department of Veterans
Affairs, or the U.S. Government.
Peter G. Vernig
Radiation Safety Officer, VA Medical Center, 1055 Clermont St. Denver,
CO 80220, ATTN; RSO MS 115
303-399-8020 ext. 2447, peter.vernig@med.va.gov [alternate for business
- vernig.peter@forum.va.gov; private - peter_vernig@hotmail.com] Fax
303-393-5026 [8 - 4:30 MT service] Alternate Fax 303-377-5686
"...whatever is true, whatever is noble, whatever is right, whatever is
pure, whatever is lovely, whatever is admirable, if anything is found to
be excellent or praiseworthy, let your mind dwell on these things."
Paul
-----Original Message-----
From: RadiumProj@cs.com [mailto:RadiumProj@cs.com]
Sent: Wednesday, November 29, 2000 9:45 AM
To: Multiple recipients of list
Subject: Re: Radioactive "seed" treatment no threat to others- ISOTOPE??
Is anyone familiar with the radionuclide used in the specific seeds tested
in
the following study noted in a post to radsafe? I would think it is Iodine
based and not Pd-103. Any insights from people closer to this issue?
Stewart Farber
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