Projects and Aims
Regularly Produced, Metallic Radionuclides for Cancer Research and Theranostic Application
Cu-64 and Hg-197(m)
Copper-64 is produced weekly by proton irradiation of enriched Ni-64 via the 64Ni(p,n)64Cu nuclear reaction. Hg-197(m) is produced bimonthly, or monthly by proton irradiation of gold via the 197Au(p,n)197(m)Hg reaction . In collaboration with colleagues from the Nuclear Physics Insitute of the CAS, Řež (Czech Republic), Hg-197(m) is also produced by deuteron irradiation of gold via the 197Au(d,2n)197(m)Hg reaction. Under certain conditions, both radionuclides can be produced simultaneously, i.e. irradiating a single target with both gold and the deposited, enriched nickel.
There are important challenges for producing Cu-64 and Hg-197(m) that must be kept in mind. There is a lot of naturally occurring copper making the production of Cu-64 with high specific activity very difficult. Devices and chemicals must be prepared or purchased as “copper free”. Additionally, the very expensive target material, enriched Ni-64, must be efficiently recycled for repeated use and electrolytic deposition to reduce production costs.
In the case of Hg-197(m), high specific activity is easier to achieve due to the significantly lower abundance of mercury in devices and chemicals. This is critical for mercury to enable its use in concentrations well below the known toxicity limits. Gold is naturally enriched and as starting material is comparatively cheap and does not have to be recycled for reuse. The relatively lower yield of the nuclear reaction, however, places high demands on both efficiency in radionuclide production / separation as well as on the subsequent radiolabeling reactions. The high volatility and the generally low water solubility of organic Hg compounds are also different to other metallic radiunuclides. Furthermore, the presence of two nuclear isomers with different properties makes the simple activity determination by "activimeter" difficult. If all problems are successfully solved, Hg-197 (m) is a very promising radionuclide for theranostic use.
Ni-Target (links) und Au-Target (rechts)
Comparison of the dose range of Cu-64 and Cu-67 in water 
Dose distribution of both nuclear isomers Hg-197 and Hg-197m in mixture and separate and compared to the well-known therapeutically-used weak beta emitter Lu-177 and the SPECT isotope In-111 
Further Metallic Radionuclides for Imaging Purposes Produced on Request
Cu-61, Y-86, Zr-89 [2,4]
Copper-61, as short-lived positron emitter (t1/2 = 3.3 h), is an alternative copper isotope to Cu-64. It is very suitable for the imaging of fast biological processes (similar to fluorine-18). Yttrium-86 is a positron-emitter that allows for preliminary imaging and dose determination prior to therapy with Y-90 conjugates. With its long half-life (t1/2 = 78.4 h), Zr-89 is a positron emitter perfectly suited for radiolabeling antibody conjugates with long biological half-lives. They are produced according to the following nuclear reactions: 64Zn(p,α)61Cu-61, 86Sr(p,n)86Y and 89Y(p,n)89Zr.
 M. Walther, S. Preusche, S. Bartel, G. Wunderlich, R. Freudenberg, J. Steinbach, H.-J. Pietzsch. Appl. Radiat. Isot. 2015, 97, 177
 S. Thieme, M. Walther, S. Preusche, J. Rajander, H.-J. Pietzsch, J.-O. Lill, M. Kaden, O. Solin, J. Steinbach. Appl. Radiat. Isot. 2013, 72, 169
 S. Thieme, M. Walther, H.-J. Pietzsch, J. Henniger, S. Preusche, P. Mäding, J. Steinbach. Appl. Radiat. Isot. 2012, 70, 602
 M. Walther, P. Gebhardt, P. Grosse-Gehling, L. Würbach, I. Irmler, S. Preusche, M. Khalid, T. Opfermann, T. Kamradt, J. Steinbach, H.-P. Saluz. Appl. Radiat. Isot. 2011, 69, 852
 Internal report of T. Kormoll, AG Strahlungsphysik, Institut für Kern- und Teilchenphysik, TU Dresden
 Calculation and graphic of R. Freudenberg, Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Carl Gustav Carus an der TU Dresden
Dr. Martin Walther (head of the group)
Christian Jentschel (technical assistant)