Re: Doses in PET centers

[fegallag@uci.edu (Frank E. Gallagher, III)]

I am also interested in information on PET doses, so I am posting
information about our experiences to radsafe.  We operate a PET Center, with
cyclotron, in the Brain Imaging Center, Dept. of Psychiatry, College of
Medicine of the University of California, Irvine.  Our primary use is F-18
FDG, but we also use F-18 F-L-Dopa and are developing methods to radiolabel
other F-18 radiopharmaceuticals.
>
>More specifically, I would appreciate the following data for your
>center:
>
>1.  No. of PET personnel.

     One health physicist assigned essentially full time to the facility.
He also serves as the cyclotron operator and performs target maintenance.
     Two radiochemists (professor and postdoc) who perform the
radiochemistry.  The senior radiochemist also does research to develop
methods to label other radiopharmaceuticals.
     Two physicians (nucl med specialist and psychiatrist) and a nuclear med
technologist who share the duties of administering F-18 to patients/human
subjects.
     One electronics technician who also does maintenance on targets and
other internal cyclotron components.
      
>2.  Approximate total mCi of PET compounds handled per month (or week
>or day if that is simpler).

     We usually produce about 600 mCi of FDG 3 days per week and make about
200 mCi of FDG.  This can easily accommodate 7 or 8 patients/human subjects
(5 mCi each) but workload has fallen off lately due to lack of research
funding and we now do 1 or 2 patients/human subjects per day.
     We usually produce about 1 Ci of F-18 one day per week and make about
75 mCi of F-L-Dopa.  This can easily accommodate 3 or 4 patients/human
subjects but we usually only have one.
     We also usually produce approx. 500 mCi of F-18 one day per week to be
used for research on developing new labeled radiopharmaceuticals--this
actiually results in the most exposure to one of the radiochemists.

>2.  Range of "whole body" and finger doses among personnel during a
>typical month.

     Using data for Jan-Nov 1995, we had the following doses for those 11
months:
          Individual(s)                 rem DDE        rem SDE-finger
          Health Physicist              0.120               0.580
          Radiochemist (Professor)      0.030               8.540
          Radiochemist (Postdoc)        Not detectable      0.310
          Nucl Med Physician*           Not detectable      0.020
          Psychiatry Physician          Not detectable      3.110
          Nucl Med Technologist*        0.120               0.510        
          Electronics Technician        Not detectable      1.480

*Partial year only.

>3.  Highest doses recorded, and explanation for same.

     The Radiochemist (Professor) receives higher hand exposures during
development of new radiopharmaceuticals and the health physicist and
electronics technician receive their exposures primarily from target
maintenance and repair of internal cyclotron components

>4.  Your ALARA trigger levels for dose (quarterly or whatever) for
>PET personnel, and how often they are exceeded.

     Our ALARA Level I is set at annual doses equal to 10% of the limits
(e.g., 0.5 rems DDE and 5 rems SDE).  Level I will be exceeded by one person
in 1995--for SDE-finger.  We have had more individuals exceed this level,
and have had higher total doses, in prior years.  Our automated
radiochemistry system has led to lower doses. 
     Our ALARA Level II is set at annual doses equal to 30% of the limits.
No doses reached these levels in 1995.



Frank E. Gallagher, III, CHP
RSO, Univ. of California, Irvine 92717-2725
Phone: (714) 824-6904, Fax: (714) 824-8539
E-mail: fegallag@uci.edu