[ RadSafe ] Tc-99m

[Daniel F. Kane]

In general the effective half - life (which considers both the biological 
half-life and the physical half-life of Tc-99m) is considered from a 
dosimetry standpoint to be six hours. At least that is what the 
manufacturers state in their package inserts.

The radiopharmaceutical (either MDP or HDP) binds to the hydroxyapatite 
crystals of bone in a manner that is related to blood flow or metabolism. 
High blood flow/metabolism equals higher uptake which often suggests some 
disease or injury process. My guess is that once bound to the bone, it stays 
there. At least 50% of the injected agent is excreted by urine in the first 
few hours.

I doubt that anyone knows what effect homeopathic chelating agents may have 
on this agent but usually just drinking more water suffices to clear the 
body of the agent rapidly and safely. Simply increase your water intake 
thereby increasing your urine output and facilitating the removal of any 
agent not bound to your bone.

Of course, one should discuss this all with the physician supervising the 
test who has full access to your medical history and physical state. The 
nuclear medicine physician responsible for your care should be consulted.

Dan Kane
Associates in Medical Physics, LLC
www.medphysics.com


----- Original Message ----- 
From: "Piotr Bein" <piotr.bein at imag.net>
To: <radsafe at radlab.nl>
Sent: Thursday, May 11, 2006 2:53 PM
Subject: [ RadSafe ] Tc-99m


> What is the biological half life in a scan of a broken wrist?
> What are the features of the carrying agents? Is there a mobilization 
> solution to facilitate clearance or is the product already designed  for 
> clearance?
> Is the use of homeopathic chelating agents recommended to clean blood  and 
> suck up the isotope?
>
> Piotr Bein
>
>
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