New activation cross section data on longer lived radio-nuclei produced in proton induced nuclear reaction on zirconium

Nuclear reaction data for medical and industrial applications: recent contributions by Egyptian cyclotron group

Measurement and evaluation of nuclear data of radioisotopes used as tracers are continuously underway in many laboratories to reach high accuracy for their use in production. We briefly mention some of the radionuclides useful for medical diagnostics and other industrial applications. The research group at the Egyptian cyclotron facility (EGCF) performed in collaboration with nuclear research centres and universities in many countries (Germany, Hungary, Finland, USA, Japan and Saudi Arabia) some measurements and evaluations of interesting nuclear reaction data. Nuclear reactions induced by p, d and α-particles on a wide variety of targets were extensively studied from threshold energy up to 50 MeV. Nuclear model code calculations, mainly using EMPIRE and TALYS, were performed for nuclear data validation. Proton and neutron activation of some industrially interesting samples were also studied as technological application of nuclear analytical techniques. Since the cyclotron facility is dedicated to development of the production routes of medical radioisotopes, this overview presents examples of optimization experiments to establish good production conditions.

Prospects for the production of radioisotopes and radiobioconjugates for theranostics

The development of diagnostic methods in medicine as well as the progress in the synthesis of biologically active compounds allows the use of selected radioisotopes for the simultaneous diagnosis and treatment of diseases, especially cancerous ones, in patients. This approach is called theranostic. This review article includes chemical and physical characterization of chosen theranostic radioisotopes and their compounds that are or could be useful in nuclear medicine.

Cyclotron Production of PET Radiometals in Liquid Targets: Aspects and Prospects

The present review describes the methodological aspects and prospects of the production of Positron Emission Tomography (PET) radiometals in a liquid target using low-medium energy medical cyclotrons. The main objective of this review is to delineate and discuss the critical factors involved in the liquid target production of radiometals, including type of salt solution, solution composition, beam energy, beam current, the effect of irradiation duration (length of irradiation) and challenges posed by in-target chemistry in relation with irradiation parameters. We also summarize the optimal parameters for the production of various radiometals in liquid targets. Additionally, we discuss the future prospects of PET radiometals production in the liquid targets for academic research and clinical applications. Significant emphasis has been given to the production of ⁶⁸Ga using liquid targets due to the growing demand for ⁶⁸Ga labeled PSMA vectors, [⁶⁸Ga]- Ga-DOTATATE, [⁶⁸Ga]Ga-DOTANOC and some upcoming ⁶⁸Ga labeled radiopharmaceuticals. Other PET radiometals included in the discussion are ⁸⁶Y, ⁶³Zn and ⁸⁹Zr.

Evaluation of nuclear reaction cross sections for optimization of production of the non-standard positron emitting radionuclide 90Nb using proton induced reactions on Zr target

Niobium-90 radionuclide is one of the promising candidates for the positron emission tomography (PET) technique. In this study, ⁹⁰Nb excitation functions via ⁹⁰Zr(p,n) and ^natZr(p,xn) reactions were computed using the TALYS-1.95 code based on phenomenological and microscopic level density models. The MCNPX simulation code was used for each case. Moreover, the target thicknesses were obtained using the SRIM-2013 code and the theoretical and simulation-based production yields of the ⁹⁰Nb were evaluated. The experimental production yield amounts of about 72.68 and 126.7 (both in MBq/μAh) for ⁹⁰Zr(p,n) and ^natZr(p,xn) reactions in the corresponding optimal energy windows were attained by our experiments respectively.

Calculation of 89Y(p,x)86,88,89gZr, 86g,87g,88gY, 85gSr, and 84Rb reaction cross sections based on level density

Excitation functions based on level density were calculated for proton-induced on yttrium-89 using the TALYS-1.8 code. Hence, production cross-section of the ⁸⁹Y(p,x)^86,88,89gZr, ^86g,87g,88gY, ^85gSr, and ^84gRb were computed up to 50 MeV. In this study, the constant temperature model alongside the Fermi Gas model (CGCM) was employed as a default model. For this reason, the a-parameter as an essential parameter in the Fermi Gas formula was modified to obtain the best result. Besides, the Back-shifted Fermi Gas Model (BSFGM) and the Generalized Superfluid Model (GSM) are presented to the deliberation. The outcomes of cross-sections were compared with the experimental data approaching regarding desired consequences.

The Beginning and Development of the Theranostic Approach in Nuclear Medicine, as Exemplified by the Radionuclide Pair 86Y and 90Y

In the context of radiopharmacy and molecular imaging, the concept of theranostics entails a therapy-accompanying diagnosis with the aim of a patient-specific treatment. Using the adequate diagnostic radiopharmaceutical, the disease and the state of the disease are verified for an individual patient. The other way around, it verifies that the radiopharmaceutical in hand represents a target-specific and selective molecule: the "best one" for that individual patient. Transforming diagnostic imaging into quantitative dosimetric information, the optimum radioactivity (expressed in maximum radiation dose to the target tissue and tolerable dose to healthy organs) of the adequate radiotherapeutical is applied to that individual patient. This theranostic approach in nuclear medicine is traced back to the first use of the radionuclide pair 86Y/90Y, which allowed a combination of PET and internal radiotherapy. Whereas the β-emitting therapeutic radionuclide 90Y (t½ = 2.7 d) had been available for a long time via the 90Sr/90Y generator system, the β⁺ emitter 86Y (t½ = 14.7 h) had to be developed for medical application. A brief outline of the various aspects of radiochemical and nuclear development work (nuclear data, cyclotron irradiation, chemical processing, quality control, etc.) is given. In parallel, the paper discusses the methodology introduced to quantify molecular imaging of 86Y-labelled compounds in terms of multiple and long-term PET recordings. It highlights the ultimate goal of radiotheranostics, namely to extract the radiation dose of the analogue 90Y-labelled compound in terms of mGy or mSv per MBq 90Y injected. Finally, the current and possible future development of theranostic approaches based on different PET and therapy nuclides is discussed.

Utilization of GEANT to calculation of production yield for 89Zr by charge particles interaction on 89Y, natZr and natSr

The ⁸⁹Zr, is one of the radionuclide with near-ideal properties for PET due to its suitable half-life and decay properties. The cross-section of ⁸⁹Zr via ⁸⁹Y(p,n)⁸⁹Zr, ⁸⁹Y(d,2n)⁸⁹Zr, ^natSr(α,xn)⁸⁹Zr and ^natZr(p,pxn)⁸⁹Zr, were calculated by the TALYS-1.8 code to predict the optimum range of charge particle energy. The Monte Carlo code GEANT4 was used to simulate the formation of ⁸⁹Zr in the target body. The simulated ⁸⁹Zr yield was in good agreement with published experimental results in the optimum energy range. According to the calculations, the ⁸⁹Y(p,n)⁸⁹Zr was superior to the other reactions useful to medical application.

Investigation of activation cross sections for deuteron induced reactions on strontium up to 50MeV

Excitation functions were measured for the ^natSr(d,x)^{88,87m,87g,86g,85g}Y, ^{87m,85g,83g,82}Sr, ^{86g,84g,83,82m,81g}Rb reactions by the stacked foil activation technique and high-resolution gamma-spectrometry up to 50MeV. We present the first experimental activation cross section data for all investigated reactions. Our experimental data are compared with the TALYS code results as available in the TENDL-2015 on-line library. Use of deuteron induced reactions on Sr for production of medical isotopes is discussed.

Nuclear model analysis of excitation functions of proton induced reactions on ⁸⁶Sr, ⁸⁸Sr and natZr: Evaluation of production routes of ⁸⁶Y

The proton induced nuclear reactions on (86)Sr, (88)Sr and (nat)Zr were investigated for the production of (86)Y. The literature data were compared with the results of nuclear model calculations using the codes ALICE-IPPE, TALYS 1.6 and EMPIRE 3.2. The thick target yields of (86)Y were calculated from the recommended excitation functions. Analysis of radioyttrium impurities was also performed. A comparison of the various production routes showed that for medical applications of (86)Y, the reaction (86)Sr(p,n)(86)Y is the method of choice, which gives efficient yield with minimum impurities.