RE: Measurement and Calculation of Beta Emitter Radiopharmaceutic

["Jean-Francois, Stephane" <stephane_jeanfrancois@merck.com>]

Thank you for the explanation, that part I understood. My question was
really: Is the dose calibrator using a Si-32 standard for calibration ? And
how low can it goes for P-32 ? (Bremstrahlung is not as easy to detect then
I-131 gammas...)

Sorry if I was vague.

Stephane Jean-Francois, Eng., CHP

Specialiste en radioprotection/Radiation Safety Specialist
Gestion des risques/Risk Management
Merck Frosst Canada & Co
TEL: 514.428.8695
FAX; 514.428.8541
email: stephane_jeanfrancois@merck.com 


-----Original Message-----
From: Rotman Mark [mailto:MRotman@snm.org]
Sent: Thursday, December 09, 1999 9:18 AM
To: Multiple recipients of list
Subject: RE: Measurement and Calculation of Beta Emitter
Radiopharmaceutic


Dose Calibrators measure photons.  However, P-32 is a very energetic beta
emitter, thus it produces significant bremstral... (sorry I never could
spell that word)both in quantity and in energy.  The dose calibrator can
detect the brem.  The DC converts the photons which ionize the inert gas in
the chamber to electrical current, so it is really the voltage potential
that creates the readout. I am sure you can figure out the rest on your own.




Mark Rotman
Government Relations
Society of Nuclear Medicine
703-708-9000 ext 1242
703-708-9777 FAX
mrotman@snm.org
http://www.snm.org



-----Original Message-----
From: Jean-Francois, Stephane [mailto:stephane_jeanfrancois@merck.com]
Sent: Thursday, December 09, 1999 9:02 AM
To: Multiple recipients of list
Subject: RE: Measurement and Calculation of Beta Emitter
Radiopharmaceutic


In at least two posting, people are talking about dose calibrators.

Can I express my desire to learn more about nuclear medicine and ask how a
dose calibrator works for P-32 ? (being a Beta emittor).

Also, if the supplier is assuring you fo a certain activity of P-32 at the
calibration date for a serynge, can't you simply wait for decay
(calculation)and inject the stuff, assuming a certain error ? (Again I don't
know enough on nuclear medicine to figure it out by myself.)

Just curiosity...

Stephane Jean-Francois, Eng., CHP

Specialiste en radioprotection/Radiation Safety Specialist
Gestion des risques/Risk Management
Merck Frosst Canada & Co
TEL: 514.428.8695
FAX; 514.428.8541
email: stephane_jeanfrancois@merck.com 


-----Original Message-----
From: Rotman Mark [mailto:MRotman@snm.org]
Sent: Wednesday, December 08, 1999 4:04 PM
To: Multiple recipients of list
Subject: RE: Measurement and Calculation of Beta Emitter
Radiopharmaceutic
 CUT

....determine
mathematically its theoretical activity based on the manufacturers assay,
and adjust the pot setting on your dose calibrator until you get a read out
that matches.  

CUT

Mark Rotman
Government Relations
Society of Nuclear Medicine
703-708-9000 ext. 1242
703-708-9777 FAX
mrotman@snm.org
http://www.snm.org



-----Original Message-----
From: Robert A Scott [mailto:bobscottchp@juno.com]
Sent: Wednesday, December 08, 1999 3:36 PM
To: Multiple recipients of list
Subject: Measurement and Calculation of Beta Emitter Radiopharmaceutical


Radsafers:

	In RI we have just received the revised regulations of the Radiation
Control Agency.  And one of our docs wants to treat a patient with sodium
phosphate (P-32) for polycythemia vera.  The order is for 3.2 mCi, but
vendors only supply in 5 mCi (5 ml) vials or syringe.  Are there any
vendors out there who supply unit doses of sodium phosphate (P-32)?  The
new regs say that if I cannot obtain a unit dose, I have to be able to
measure or measure and calculate the dose using some method other than a
simple comparison technique with a photon dose calibrator.  Then whatever
method I use, I have to document and describe the assay technique and
hold this documentation for 3 years.

	I thought of a basic internal standard liquid scintillation
technique,
but such standards are not routinely available anytime we want.  

	So how do we do this?  Or am I interpreting this regulation too
literally?  Any help will be greatly appreciated.

Bob Scott, RPO 
Roger Williams Medical Center
Providence, Rhode Island
bobscottchp@juno.com
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