Tuesday, 9 April 2013

Solving the medical isotope problem

One of the nice things about this year's Institute of Physics nuclear physics conference is that we have a few attendees from universities which don't usually send people.  It seems, perhaps, that nuclear physics activity in the UK is growing, or at least that some of the more applied nuclear physicists are joining in community events.

Yesterday, I attended two interesting talks by people form such non-traditional universities;  Huddersfield and Cambridge (nice to be able call Cambridge a non-traditional university).  Both speakers were concerned with performing simulations of nuclear reactions induced by small-scale low-energy particle accelerators in order to produce medical isotopes.  One of the most important medical isotopes is technetium-99m (Tc-99m).  It is normally produced by taking molybdenum-99 from nuclear reactors, and letting that decay to technetium-99m.  The "m" means that the technetium is in an excited state, and it decays by X-ray emission.  By preparing a suitable technetium compound that targets particular parts of the body when ingested, the position of the emitted X-rays can be measured.

Through various reasons, including unplanned reactor shut-downs, the worldwide production of Tc-99m has decreased markedly.  The groups at Cambridge and Huddersfield are looking at new, non-reactor-based ways of producing it, and indeed other medical radionuclides.

The picture associated with this post is from a poster presented by Naomi Ratcliffe, from Huddersfield, available from the Huddersfield website.  It relates to some of the simulations of neutron yields that she presented in her talk.


  1. It's a serious issue in that a lot of the UK research reactor capability which we once had is now gone. For the sorts of research project that we do we use custom made particles that are neutron-activated for use in human volunteer experiments. I'm not sure whether the reactor at Imperial College is still operating, but that was the last place we had in the UK to get the material we needed for experiments.

    I'm not sure we can import these from outside UK given the amount of hassle we had last time. It is surprisingly difficult getting hold of isotopically pure radionuclides from other countries who still had the facilities for these things.. :(

  2. Good stuff. I am glad Will's and Naomi's talks went well.

    There is so much research outside of the fray of traditional nuclear physics research in the UK which is of absolute interest to the nuclear physics community, it always fills me with wonder as to why the various communities have such little interaction between them.

    In both their work, there is so much overlap in this area with the field of nuclear astrophysics, of which arguably the astrophysics community is one step ahead. Although, the proton- and neutron-induced reaction cross-sections can be calculated to reasonable accuracy, there still needs to be accurate experiments to test these simulations on key nuclei.

    Arron: regarding research reactors, my understanding is that Consort is being decommissioned. From a UK perspective, there is sizable contribution towards the Jules-Horowitz Reactor in Cadarache, which the UK National Nuclear Laboratory is leading. This was part of the recently published Nuclear Industrial Strategy. Depending on the flux of neutrons needed, you may want to make enquiries to see if the thermal pile in NPL's neutron metrology group would be of any use.

  3. I suppose it's always hard to know where to draw the lines between areas. Such lines are always going to be a bit arbitrary. The line between nuclear and particle physics is not very well defined, for example. but the fact that the talks by Will and Naomi were well attended and of interest to the rest of the attendees probably means that they are definitely the kind of people who should be coming to the IoP nuclear physics conference. i wonder what they made of the rest of the talks. Should have have asked them, really!

  4. Thanks for clarifying what 'm' means in isotope names! I had wondered ... :-)

    1. No problem! I probably should have mentioned that it literally stands for "metastable," but it's not exactly an everyday term.

      Actually, speaking of things that we should bring to the attention of the nuclear physics community, maybe something about nuclear clocks should come up at next year's conference :-)