Radiotracer Decay - What's Left?

  • Thread starter Chyral
  • Start date
  • #1
2
0
Greetings all. I'm a just a chemist banging my head about some what seems to me as fundamentally a nuclear physics question, so please bear with me.

If you have a molecule bearing a radioactive atom, a PET radiotracer, say F-18 FDG or some such beast, and it decays (to O-18 correct?) what exactly happens to the entire molecule? Another way of putting it is: As the positron-neutrino pair is released, is the rest of the tracer molecule blown apart by kinetic energy from the decay event?
Or am I thinking too much in a classical sense and you are left with a molecule happily bearing O-18 rather than F-18?
And lastly, does the answer depend on what type of decay is occurring?
 

Answers and Replies

  • #2
malawi_glenn
Science Advisor
Homework Helper
4,795
22
It depends on the electron configuration of the radioactive elements daugher.

You can look on wikipedia for example, on all decay modes. Then there are things like "Internal conversion", "electron capture"; which changes the electron configuration of the daugher atom.
 
  • #3
2
0
Thanks for the reply! So it looks like this was the wrong place to post (sorry about that). I have asked people here in radiochemistry and medical physics and I still am left without an answer, though. Oh well.
 
  • #4
345
3
I'm not a radiochemist, but I believe that most of the time the daughter product dissociates from the tagged molecule/pharmaceutical (which remains intact)
 
  • #5
80
0
If you have a molecule bearing a radioactive atom, a PET radiotracer, say F-18 FDG or some such beast, and it decays (to O-18 correct?) what exactly happens to the entire molecule? Another way of putting it is: As the positron-neutrino pair is released, is the rest of the tracer molecule blown apart by kinetic energy from the decay event?
Or am I thinking too much in a classical sense and you are left with a molecule happily bearing O-18 rather than F-18?
And lastly, does the answer depend on what type of decay is occurring?

Hello Chyral,

I would say that the recoiling of the nucleus is negligible (specially for F) wrt the energy of positron-neutrino pair. In some way, that's why you can do imaging.
 

Related Threads on Radiotracer Decay - What's Left?

Replies
5
Views
2K
Replies
15
Views
3K
  • Last Post
Replies
15
Views
5K
  • Last Post
Replies
6
Views
18K
  • Last Post
Replies
5
Views
4K
Replies
7
Views
672
Replies
46
Views
4K
Replies
12
Views
17K
  • Last Post
Replies
8
Views
2K
Replies
18
Views
2K
Top