Re: Y-90 Medical Use -Reply

["Mike Bohan" <mike.bohan@yale.edu>]

        Reply to:   RE>>Y-90 Medical Use -Reply

Ken and RadSafe,

The NRC Reg guide uses the physical decay of the radionuclide in question to conservatively calculate the max. dose to the significant other.  The rule allows  the licensee to use other assumptions such as biological turnover and self shielding to do their own estimates.  

As long as they can demonstrate that  the assumptions are reasonable (That's a wonderful word for the regulatory vernacular!), and that the max dose is less than 500 mRem EDE and keep the calculations on file for 3 years along with a copy of the written instructions given to the patient, the NRC says it's golden!  

I calculate that using reasonable excretion rate assumptions and self shielding data, you could justify releasing patients even above 150 mCi of I-131.  Remember, they usually excrete 70% of the administered dose within 24 hrs.

As for Y-90, I'm leaving tomorrow for Washington, DC to attend a conference on intravascular brachytherapy (IVB),  I see if I can fill you all in on it when I get back.

Cheers and see you all the week after next,
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Michael J. Bohan, RSO   |  e-mail: mike.bohan@yale.edu
Yale-New Haven Hospital |    Tele: (203) 688-2950
Radiological Physics    |     FAX: (203) 737-4252
20 York St. - WWW 204   |    As usual, everything I say may be plausibly
New Haven, CT    06504  |    denied at my employer's convenience ...
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