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RE: "Oops, I did it, again." (medical misadministration)



Title: RE: "Oops, I did it, again." (medical misadministration)
Our release critieria is based upon the 7 mrem/hr at 1 meter.  The average release last year was 4.6 mrem/hr.  The average patient stay last year was 18.9 hr.  The average initial reading at 1 meter was 13.1 mrem/hr.  
 
The largest dose to a patient I have seen was 500 mCi, very unusual.  I don't remember the initial meter reading, but I do remember we had to barricade the hallway so we would have no one pass through the area.
 
Kaye Larson
 
-----Original Message-----
From: Jacobus, John (OD/ORS) [mailto:jacobusj@ors.od.nih.gov]
Sent: Friday, June 14, 2002 3:15 PM
To: radsafe@list.vanderbilt.edu
Subject: RE: "Oops, I did it, again." (medical misadministration)

We dose patients up to 300 mCi, who may have advanced metastatic disease.  We measure the exposure rate at 1 meter after the dosing on Friday, and again the following Monday.  A ratio of the doses to exposure rates allows us to determine the amount of activity in the patient.  If less than 33 mCi is left, or less than 7 mrem/hr at 1 meter is our release criteria. 
 
To a patient who has active thyroid cancer, the risk of inducing cancer from radiation is a moot point.
 

-- John

John Jacobus, MS, CHP
Area Health Physicist
Radiation Safety Branch
National Institutes of Health
21 Wilson Drive, MSC 6780
Bethesda, MD  20892-6780
USA
Telephone:  301-496-5774
Fax: 301-496-3544
E-mail:  jjacobus@mail.nih.gov
         jacobusj@ors.od.nih.gov

-----Original Message-----
From: Larson, Kaye M BAMC-Ft Sam Houston [mailto:Kaye.Larson@CEN.AMEDD.ARMY.MIL]
Sent: Friday, June 14, 2002 3:31 PM
To: Jacobus, John (OD/ORS); 'William V Lipton'; radsafe@list.vanderbilt.edu
Subject: RE: "Oops, I did it, again." (medical misadministration)

120 mCi is an average to below average dose for a thyroid ablation, but of course it depends upon the patient size, the thyroid uptake, and the disease. You missed the dose to the bladder.  A very important consideration when ablating the thyroid, if your interest is the patient.   One reason why the patient is asked to drink much in the way of fluids while the ablation takes place.
 
The third method of release is;  "Release of Patients Based on Patient Specific Dose Calculations", which you will find in the Reg Guide 8.39.  The method of calculations used are within that Reg Guide, and the calculations I was referring.  We do not release patients by this method at this facility, so the ins and outs of doing so will have to be discussed with a Health Physicist that does so.  But within the calculations you will find the specific dose calculations are based up a reading taken at one meter.  (As my course numbers were).  Many facilities find that they can release most of their patients by the standards found within Reg Guide 8.39.  So it is of no surprise to the medical health physicists that a patient could be given a dose of 120 mCi, be released, and not in violation of their license. But this is speculation, not knowing all the circumstances, and not the true problem.  
 

 . . .