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Submitted on 16 Dec 2019
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Radioactive isotopes produced for medical applications: setting up an accurate measurement method for
production cross section
Etienne Nigron, Ferid Haddad, Arnaud Guertin
To cite this version:
Etienne Nigron, Ferid Haddad, Arnaud Guertin. Radioactive isotopes produced for medical applica-tions: setting up an accurate measurement method for production cross section. Journée de l’école doctorale 3M, Jun 2017, Angers, France. �hal-02414668�
Introduction
E. Nigron
(1)*, F. Haddad
(1,2), A. Guertin
(1)(1)Laboratoire SUBATECH – IMT Atlantique, CNRS / IN2P3, Université de Nantes
4, rue Alfred Kastler 44307 Nantes cedex 3 France
(2)ARRONAX cyclotron – 1, rue Aronnax – CS 10112, 44817 Saint-Herblain cedex - France
Radioactive isotopes produced for medical applications: setting up an accurate
measurement method for production cross section
*nigron@subatech.in2p3.fr
Objective
Methods
Set up & Results
Discussion & Conclusion
The nuclear medicine is a medical specialty that uses radionuclides for diagnosis or therapy. They are mostly used coupled to a vector which constitute a radiopharmaceutical.
Set up an accurate measurement method for production cross section and complete database.
Imaging
SPECT
(Single Photon Emission Computed Tomography)
Therapy
PET
(Positron Emission Tomography)
It uses photon emissions which are penetrating radiation to locate cancer cells. Photons are generated :
Directly by the radionuclide decay of some radionuclides
Indirectly by the annihilation of the emitted positron with a nearby electron creating a pair of 511 keV photons.
Strongly interacting particles obtained through the radioactive decay are used such as alpha, beta - or Auger electrons. Their energy losses in the matter are higher than photon energy. This released energy is used to destroy cancer cell.
The production of radionuclides can be obtained using reactor or accelerator. In order to have a good control of the quality of the final product, the knowledge of the radionuclide production cross section (a physic variable expressing the probability that a reaction occurs) is required.
In collaboration with the GIP ARRONAX(2) which
possesses a multi-particle high energy cyclotron, the project is :
To get an accurate measurement of production cross sections Explore alternative production route
Assess the final product quality.
To measure cross sections, the “stacked-foils” technique is used.
Among the information requires for a precise measurement, the flux of the incident particle is the more important one. It can be evaluated with :
Monitor reaction with a well-known cross section whose values are recommended by the International Atomic Energy Agency (IAEA). Considering the constant flux of particles throughing the stack :
The uncertainty (around 10%) associated to the monitor cross section values results in a high uncertainty on the measured ones.
Measure the amount of charges crossing the stack. This method allows reducing the uncertainty on the measured flux and therefore of the cross section (expected uncertainties are of the order of a few percent). 0 50 100 150 200 250 300 350 400 0 10 20 30 40 50 60 C ros s s e c ti on (m b)
Energy of incidents alphas (MeV)
Cu(a,x)67Ga Rattan (1986) Tarkanyi (2000) Szelecsenyi (2001) Szelecsenyi (2012) Shahid (2015) IAEA My work - Monitor My work - Charge
E ± ΔE (MeV) σ monitor (mb) σcharge (mb) IAEA (mb)
40,91 ± 0,75 75,53 ± 7,84 71,26 ± 1,38 63,6 37,52 ± 0,80 152,67 ± 15,91 125,39 ± 2,309 115,3
In order to use this technique, a new experimental cross section measurement device has been set up and it is being tested in well-known conditions.
The results obtained show that the new device works well and the results are in good agreement with the IAEA recommended cross section values and other available data in the literature. This satisfying results show that this device can be used to measure cross sections and it will allow measuring production cross section values for radionuclides of interest which are still missing in the databases.
cancer cell Vector Radiopharmaceutical Emitted particle Particle Average route (µm)** Stopping power (keV/µm)** Beta - 2000 0,2 Auger e- <10 1-10 Alpha 50 80 **Values in tissues « Stacked-foils » Alumina 1 2 3
1. Stacked foils base
2. The device contening stacked foils base 3. The device set up at Arronax
The “stacked-foils” technique :
