High Specific Activity Radionuclides Research Articles

Cyclotron production and radiochemical separation of 55Co and 58mCo from 54Fe, 58Ni and 57Fe targets

This work presents the production with a cyclotron of the positron emitter 55Co via the 54Fe(d,n) and 58Ni(p,α) reactions and the Auger electron emitter 58mCo via the 57Fe(d,n) reaction after high current (40μA p and 60μA d) irradiation on electroplated targets. High specific activity radionuclides (up to 55.6 GBq/μmol 55Co and 31.8GBq/μmol 58mCo) with high radionuclidic purity (99.995% 55Co from 54Fe, 98.8% 55Co from 58Ni, and 98.7% 58mCo from 57Fe at end of bombardment, EoB), in high activity concentration (final separated radionuclide in < 0.6mL) and with almost quantitative overall activity separation yield (> 92%) were obtained after processing of the irradiated targets with novel radiochemical separation methods based on HCl dissolution and the resin N,N,N′,N′-tetrakis-2-ethylhexyldiglycolamide (DGA, branched). One hour long irradiations using 38–65, 110–214 and 59–78mg of enriched 54Fe (99.93%), 58Ni (99.48%) and 57Fe (95.06%), respectively, electroplated over a 1.0cm2 surface, yielded 582 ± 66MBq 55Co, 372 ± 14MBq 55Co and 810 ± 186MBq 58mCo, respectively, decay corrected to EoB. The separation methods allow for the recovery of the costly enriched target materials, which were reconstituted into metallic targets after novel electroplating methods, with an overall recycling efficiency of 93 ± 4% for iron. The produced radionuclides were used to radiolabel the angiogenesis marker antibody TRC105 conjugated to the chelator NOTA as a demonstration of their quality.

A preliminary study for the production of high specific activity radionuclides for nuclear medicine obtained with the isotope separation on line technique

Radiopharmaceuticals represent a fundamental tool for nuclear medicine procedures, both for diagnostic and therapeutic purposes. The present work aims to explore the Isotope Separation On-Line (ISOL) technique for the production of carrier-free radionuclides for nuclear medicine at SPES, a nuclear physics facility under construction at INFN-LNL. Stable ion beams of strontium, yttrium and iodine were produced using the SPES test bench (Front-End) to simulate the production of 89Sr, 90Y, 125I and 131I and collected with good efficiency on suitable targets.

Chemistry and radiochemistry of As, Re and Rh isotopes relevant to radiopharmaceutical applications: high specific activity radionuclides for imaging and treatment.

The chemistry and radiochemistry of high specific activity radioisotopes of arsenic, rhenium and rhodium are reviewed with emphasis on University of Missouri activities over the past several decades, and includes recent results. The nuclear facilities at the University of Missouri (10 MW research reactor and 16.5 MeV GE PETtrace cyclotron) allow research and development into novel theranostic radionuclides. The production, separation, enriched target recovery, radiochemistry, and chelation chemistry of 72,77As, 186,188Re and 105Rh are discussed.

Experimental results and model calculations of excitation functions relevant to the production of specific radioisotopes for metabolic radiotherapy and for pet

First results are given from the comparison of experimental values and model calculations on accelerator-produced high specific activity radionuclides in no-carrier-added (NCA) form. The relevant radioisotopes are: 64Cu, produced by natZn(d, αxn) and natZn(d,2p) reactions, for simultaneous positron/negatron metabolic radiotherapy and PET imaging; 66Ga high-energy positron emitter (4.2 MeV), produced by natZn(d, xn) reactions, for metabolic radiotherapy and for PET; 186gRe, produced by 186W(p,n) and 186W(d,2n) reactions, for negatron (1.1 MeV) metabolic radiotherapy; 211At/ 211Po, produced by 209Bi( α,2n) reaction (with spike of gamma emitter 210At produced by 209Bi( α,3n) reaction) and 225Ac/ 213Bi/ 213Po, produced by 226Ra(p,2n) reaction, both for high-LET radiotherapy.

High specific activity radioactive tracers: a powerful tool for studying very low level and long term exposure to different chemical forms of both essential and toxic elements

Both essential and toxic elements are present in the biosphere in different inorganic and organo–metallic forms. Some trace elements like Cr, Cu, Mn, Rb, Se, Tl, V, Zn are essential to human life and are present in human tissues, body fluids, cells and sub-cellular components, bonded to enzymes, proteins, etc. Many trace elements are introduced daily in the body in amounts ranging from ng to μg per kg. A powerful tool to set up analytical procedures, to evaluate the chemical separation yield and to follow the fate of different chemical forms of ultra-trace elements on living organisms is the use of ‘high specific activity’ radioactive tracers (RT). Amongst the more effective RTs for radio-analytical chemistry, there are the short-lived medium γ-energy emitters. A review of the last 25 years in the field of both cyclotron and nuclear reactors producing high specific activity radionuclides in radio-analytical chemistry is presented. As, Au, Cu, Ga, Mn, Np, Pd, Pt, Rb, Rh, Sb, Te, Ti, Tl, V, etc., γ- and β emitting RTs have had interesting applications in the ultra-trace metallo-toxicology field. High-resolution γ-spectrometry by HPGe detection and β spectrometry by liquid scintillation counting, have been used, hyphenated with ‘elemental analysis’ radio-analytical and analytical techniques. The ‘high specific activity’ of the No Carrier Added RTs is the ‘key factor’ of this powerful radio analytical technique.

High resolution γ-spectrometry by HPGe detector and β-spectrometry by liquid scintillation counting, hyphenated to elemental analysis techniques: applications of high specific activity radio-nuclides for ultra-trace metallo-toxicological and environmental studies

Thin- and thick-target excitation functions of 188,189,191Pt radionuclides were experimentally determined by cyclotron irradiation, using nuclear reactions natOs(α,xn) in the energy range up to 38 MeV with the Scanditronix-MC40 Cyclotron of the Joint Research Centre-Ispra, VA (Italy) of the European Communities. Radionuclidic, radiochemical and chemical purities have been also measured by use of analytical and radioanalytical techniques. In this paper, the result of the experimental thick- and thin-target excitation functions of 188,189,191Pt radiotracers, produced via natOs(α,xn) reactions, are presented. The data are of relevant interest for optimising cyclotron production of platinum radionuclides to be used as radiotracers for metallo-biochemical, biomedical, toxicological and environmental studies. In this paper, we will present the analytical and radioanalytical methods that have been developed to determine the amount of isotopic carrier and the SA(NCA) in the case of 188Pt, 191Pt, to be used for ‘multiple labelling’ experiments, by: high resolution γ-spectrometry, β-spectrometry by liquid scintillation counting, neutron activation analysis, FL-AAS, and ICP-OES. Moreover, some preliminary biological applications were carried out in order to determine the cyto-toxicology of different chemical forms of platinum.

Radionuclide production at the Russia State scientific center, RIAR

Radionuclide production capabilities of the Russia State Scientific Center, the Research Institute of Atomic Reactors (RIAR) are reviewed. Radionuclides routinely produced are as follows: transplutonium element 243Am, 244–248Cm, 249Bk, 249Cf, 252Cf and high specific activity radionuclides 153Gd, 33P, 113,119mSn, 188W, 63Ni, 55,59Fe, 51Cr, 54Mn, 89Sr. Other HSA radionuclides ( 133Ba, 65Zn, 124Sb, 45Ca, 60Co, 192Ir, 169Yb, 170Tm, 75Se) are also available from RIAR. Besides radioactive preparations RIAR produces ionising neutron ( 252Cf), gamma ( 60Co, 192Ir, 75Se, 153Gd) and alpha ( 244Cm) sources for medicine, industry and research. A short description of the technology development is presented.

Irradiation methods for production of high specific activity radionuclides in no carrier added form

High Specific Activity Radio-Nuclides (HSARN) are a powerful tool to label a large range of chemical species at very low concentration levels. In order to obtain these radiotracers in a very high specific activity form, it is necessary to optimize the production methods, to separate and purify them from the irradiated target without the addition of inactive carrier, to carry out a series of analytical and radioanalytical tests to determine their “true” specific activity and to verify a series of purity parameters. A review of irradiation methods and nuclear parameters adopted in our laboratories for the preparation of some tens of radiotracers are presented.

Preparation and Purification of High Specific Activity Radionuclides for Environmental Studies

High specific activity radionuclides are a powerful tool for labeling a large range of inorganic and metallorganic species that are present in the environment at very low concentrations. In order to study the environmental impact of trace elements (TE) on the humans, it is of fundamental importance to carry out both in vitro and in vivo experiments on cell cultures and laboratory animals, with concentrations of these TE representative of the actual long-term and low-level exposures. In order to obtain these radiotracers in a very high specific activity form, it is necessary: (a) to optimize the production method by either charged particle accelerator (normally cyclotron) or nuclear reactor irradiation, (b) to separate and purify them from the irradiated target by chemical or physicochemical methods, without the addition of inactive carriers (i.e., the so-called no carrier added form), (c) to carry out a series of analytical and radioanalytical tests, in order to verify the chemical, radiochemical, and radionuclide purities of the tracer or labeled compound under investigation. Some production, separation, purification, and quality control methods developed for the two cyclotron-produced radionuclides 52gMn and 48V will be presented and discussed.

Liquid-solid extraction of high specific activity radionuclides from reactor irradiated metal phthalocyanines

Highly purified cobalt and zinc phthalocyanines were reactor irradiated and used in studies of the direct liquid-solid extraction procedure for obtaining high specific activity radionuclies. Hot dilute aqueous acid solutions, such as 0.1M HClO4, were found to give useful yields />50%/ at moderate enrichments from α-MPc targets. Dilute acid does not extract useful quantities of radionuclides from the irradiated β-MPc targets examined.