[ RadSafe ] Outpatient I-131 Therapy under attack

[Hansen, Richard]

I have a few questions about the release of patients treated with I-131
and other isotopes.

We have been training emergency responders on what radiation levels to
expect from nuclear medicine patients, and have been using the following
as our reference for the maximum radiation levels for patients released
from medical facilities:
NRC NUREG-1556, Vol. 9, Rev. 2 
Consolidated Guidance About Materials Licenses Program-Specific Guidance
About Medical Use Licenses (January 2008), 
Appendix U, Model Procedure for Release of Patients or Human Research
Subjects Administered Radioactive Materials, 
Table U.1, Activities and Dose Rates for Authorizing Patient Release.

http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1556/v9/r2/
sr1556v9r2-final.pdf#app-u

This table shows, for I-131, an "Activity At or Below Which Patients May
Be Released" of 1.2 GBq (33 mCi) and "Dose Rate at 1 Meter, At or Below
Which Patients May Be Released" of 0.07 mSv/h (7 mR/h). The highest
radiation level on Table U.1 is 0.58 mSv/h (58 mR/h) at 1 meter for 28
GBq (760 mCi) of Tc-99m.

If medical facilities are releasing patients with 200 mCi of I-1331 and
using methods other than Table U.1 to meet the requirements of 10 CFR
35.75 "Release of individuals containing unsealed byproduct material or
implants containing byproduct material" (total effective dose equivalent
to any other individual from exposure to the released individual is not
likely to exceed 5 mSv (0.5 rem)), then what are more realistic
expectations of the maximum radiation levels to be found near medical
patients upon their release?

Are patients being released when the dose rate is more than 58 mR/h at 1
meter (for any isotope)? 

What is the maximum dose rate (and for which isotope) that you know of
for which a patient could be released from a medical facility?

If you have examples detecting/measuring released patients with high
dose rates that you are willing to let us use as examples in our
DHS/FEMA training programs for emergency responders, please email me
directly. Of course, we do not want any personal identifiable
information (such as names) about any patient.

Thanks.

Best regards,
Rick Hansen
Senior Scientist
Counter Terrorism Operations Support Program
National Security Technologies, LLC, for the U.S. Dept of Energy
hansenrg at nv.doe.gov
www.ctosnnsa.org

Excerpts from previous emails on this topic
Date: Fri, 26 Mar 2010
From: gv1 at aol.com
...We had a person that would qualify as a High Radiation Area (>100
mrem/hr @ 30 cm) if it were reactor radiation and they were also
contaminating the place.  The GM Frisker can't tell medical contam from
reactor contam.  Needless to say we sent them home with pay...
Glen

From: North, David <DNorth at Lifespan.org>
Sent: Tue, Mar 23, 2010 10:56 am
>From our experience of over 700 in-patients and 600 out-patients, we
have 
measured about 0.17 mR/hr/mCi at one meter after administration. 
That works out to about 1.63 mR/hr at 15 feet from 200 mCi, and
therefore about 13 mR in 8 hours. The caution is that the exposure rate
per mCi among a bunch of patients can vary by a factor of 2 either way.
David L. North, Sc.M. DABR
Medical Physics
Rhode Island Hospital