Speaker
Description
195mPt is isomeric radionuclide with the great prospect for use in nuclear medicine, due to high yield of Auger electrons, good for small malignancies treatment, mild gamma-radiation for medication distribution control without almost any damage to healthy tissues. These properties perfectly suit personalized approach for treatment of cancer which is developed into theranostics in nuclear medicine, i.e. simultaneous therapy and diagnostics using one particular drug. However no method leading to 195mPt production with high specific activity in sufficient amounts for reasonable price is known.
In this work production method of double neutron capture of enriched 193Ir has been discussed [1]. Only 2 neutron capture cross sections are known out of 6 crucial values. It is impossible to deduce yield of 195mPt with this set of input data [2].
For calculation of the unknown cross sections the full scale model experiment at the reactor IBR-2 was carried out in Dubna. For this purpose 2 targets of 193Ir powder (98.5 enrichment, m, 20 mg each) were wrapped in 2 aluminum foils and put in 2 aluminum containers. Then irradiation with the neutron flux of 2.3x1012 cm-2s-1 during 18 days occurred. Direct measurement of 195mPt appeared to be difficult because of the enormous radiation background. Therefore dissolution and separation of Ir and Pt isotopes were undertaken. According to the requirements the most feasible option for dissolution was found to be electrochemical technique and extraction chromatography with TEVA resin and HCl eluent for separation.
With the help of the results of 195mPt radioactivity determination on HPGe gamma-detector Canberra retrieving of previously unknown cross sections was carried out.
References:
1. Knapp F.F. Jr. et al. Production of therapeutic isotopes in the ORNL High Flux Isotope Reactor (HFIR) for applications in nuclear medicine, oncology and interventional cardiology // J. Rad. Anal. Nucl. Chem. 2005. Vol. 263, №2. p. 503-509.
2. Karamyan S.A., Aksenov N.V., Albin Y. A., Belov A.G., Bozhikov G.A., Dmitriev S.N., Starodub G.Y. Methods for production of 195mPt isomer // Bulletin of the Russian Academy of Sciences. Physics, 2014. V. 78. P. 549.
