Re: Sm-153

[Louis_Hagler@BERLEX.COM]

The process that is used to produce clinically useful amounts of Sm-153 is
known to generate trace levels of radionuclidic impurities that have been
identified as isotopes of europium.  Europium-154, with a half-life of 8.6
years, is the major contaminant and is the one responsible for virtually
all of the radiation due to impurities.  From a quality assurance
perspective, the specifications for Quadramet

® call for the product to
contain less than 0.0093% of Eu-154 at expiry; this is equivalent to 0.093
microcuries of Eu-154 per millicurie of Sm-153.  In fact, the actual
measured values range from 0.06 to 0.08 microcuries of Eu-154 per
millicurie of Sm-153.

The usual hold-for-decay program requires the licensee to hold short-lived
radionuclides for at least 10 half-lives.  A 20-day period would be
appropriate for Sm-153, with a half-life of nearly 2 days.  However,
because of its long half-life, it will be possible to detect, well beyond
20 days, the microcurie amounts of Eu-154 that remain in the vial after
administration of Quadramet®.

This should not present a problem for facilities that administer Quadramet®
in the United States.  Berlex/DuPont has an established mechanism for
facilities to return Quadramet®  vials following use.  Syncor, a major
radiopharmaceutical distributor, also has a program for handling the return
Quadramet®  vials and unit dose syringes that are dispensed by Syncor..

To contact DuPont for technical information or for information about return
of the vials, please call 1-800-362-2668.

To contact Berlex for medical or patient-related information, please
contact the Professional Services Department at 1-888-237-5394 (option 4,
option 1).