Investigation of direct production of 68 Ga with low energy multiparticle accelerator

Chemical radioanalysis of production of positron-emitting radioisotope Gallium-68 via (p,n) and (p,2n) reactions using compact cyclotron for tomography applications

In this study, the proton-induced reactions of 68Zn and 69Ga aimed at generating 68Ga were simulated and modeled using Talys code and neural network software. In the first step, both targets were simulated under different proton energies and at different bombardments times to generate a total of six thousand data. Then, the obtained data from the Talys, including the various cross-sections, contaminations, the main product i.e. 68Ga, and other options were completely saved in the output file. Afterwards, the inputs of the neural network were selected from the output of the Talys by analyzing and considering most of the key features. A total of four inputs, two of which are different energies related to the reaction, the other is the process sequence and the fourth input is the bombardment time, were recognized as suitable inputs and the model was trained differently depending on the type of target. The selected model was a feed-forward neural network with 5 nodes in a middle layer, which was able to estimate the output of Talys code by changing the input parameters with extremely high accuracy. Two different models including the main model for estimating the output of the main sample (product) and the sub-model for estimating process pollution or impurity were trained, and then the trained model was tested on the deduced process data. The implementation results fully demonstrated the high accuracy of the method. The neural network model is much easier to implement than the Talys code, and its execution speed is very high. In addition, it can be used appropriately as a system alternative for optimization and different structures in medical and biological engineering.

Performance evaluation of Gallium-68 radiopharmaceuticals production using liquid target PETtrace 800 cyclotron

Due to increased demand, cyclotron has an expanding role in producing Gallium-68 (68Ga) radiopharmaceuticals using solid and liquid targets. Though the liquid target produces lower end-of-bombardment activity compared to the solid target, our study presents the performance of 68Ga radiopharmaceuticals production using the liquid target by evaluating the end-of-bombardment activity and the end-of-purification activity of [68Ga]GaCl3. We also present the effect of increasing irradiation time, which significantly improves the end-of-synthesis yield. From the result obtained, the end-of-bombardment activity produced was 4.48 GBq, and the [68Ga]GaCl3 end-of-purification activity produced was 2.51 GBq with below-limit metallic impurities. Increasing the irradiation time showed a significant increase in the end-of-synthesis activity from 1.33 GBq to 1.95 GBq for [68Ga]Ga-PSMA-11 and from 1.13 GBq to 1.74 GBq for [68Ga]Ga-DOTA-TATE. Based on the improvements made, the liquid target production of 68Ga radiopharmaceuticals is feasible and reproducible to accommodate up to 5 patients per production. In addition, this work also discusses the issues encountered, together with the possible corrective and preventative measures.

The effects of nuclear level density model and alpha optical model potential to the excitation functions of novel therapeutic radionuclides

In this study, the theoretical cross sections of 209Bi(α,2n)211At, 65Cu(α,n)68Ga, 100Ru(α,n)103Pd, and 121Sb(α,n)124I are calculated using TALYS 1.96, incorporating the effects of the alpha optical model potential and nuclear level density models. The validation process involves comparing the calculated cross sections with experimental data and utilizing statistical deviation factors. This comparison allows us to determine the optimal combination of nuclear model parameters for each reaction. The result shows that theoretical calculations which utilized semi microscopic level density models and alpha OMP managed to describe the excitation functions close to the experimental data. The comparison of nuclear model calculations with experimental data plays a crucial role in ensuring the reliability of the data, making it an essential aspect of modern evaluation procedures.

Cyclotron Production of Gallium-68 Radiopharmaceuticals Using the 68Zn(p,n)68Ga Reaction and Their Regulatory Aspects

Designing and implementing various radionuclide production methods guarantees a sustainable supply, which is important for medical use. The use of medical cyclotrons for radiometal production can increase the availability of gallium-68 (⁶⁸Ga) radiopharmaceuticals. Although generators have greatly influenced the demand for ⁶⁸Ga radiopharmaceuticals, the use of medical cyclotrons is currently being explored. The resulting ⁶⁸Ga production is several times higher than obtained from a generator. Moreover, the use of solid targets yields end of purification and end of synthesis (EOS) of up to 194 GBq and 72 GBq, respectively. Furthermore, experiments employing liquid targets have provided promising results, with an EOS of 3 GBq for [⁶⁸Ga]Ga-PSMA-11. However, some processes can be further optimized, specifically purification, to achieve high ⁶⁸Ga recovery and apparent molar activity. In the future, ⁶⁸Ga will probably remain one of the most in-demand radionuclides; however, careful consideration is needed regarding how to reduce the production costs. Thus, this review aimed to discuss the production of ⁶⁸Ga radiopharmaceuticals using Advanced Cyclotron Systems, Inc. (ACSI, Richmond, BC, Canada) Richmond, Canada and GE Healthcare, Wisconsin, USA cyclotrons, its related factors, and regulatory concerns.

Ion beam activation of natCu, natTi, natNi and measurement of product formation cross sections at low energy (<10 MeV)

In this study we investigated the production cross sections of natCu(p, x)63,65Zn, natTi(p, x)48V, natNi(p, x)55Co,61Cu and natCu(α, x)66,67,68Ga, natTi(α, x)49,51Cr, natNi(α, x)63,65Zn reactions in the low energy range using the foil activation technique. The samples were activated in vacuum at 5 MV tandem (Pelletron) accelerator installed at National Centre for Physics (NCP), Islamabad, Pakistan. The reaction products were identified with the help of off-line gamma ray spectroscopy system connected with Genie 2000 software. The data analysis revealed the production of different radioisotopes that have valuable importance in monitoring charged-particle beams and medical applications. The measured results were verified by comparing them with earlier evaluated data as well as with the theoretical values given in the TENDL-library based on TALYS-1.9 code calculations.

Special radionuclide production activities – recent developments at QST and throughout Japan

National Institutes for Quantum Science and Technology (QST), formerly known as the National Institute of Radiological Sciences (NIRS), has been engaged in work on radiopharmaceutical science using cyclotrons since 1974. Eight pioneering researchers founded the basis of this field of research at NIRS, and to the present, many researchers and technicians have accumulated both scientific and technical achievements, as well as inherited the spirit of research. Besides, in recent years, we have developed production systems with AVF-930 cyclotron for various ‘non-standard’ radioisotopes applied in both diagnosis and therapy. Here, we review the past 50 years of our activities on radioisotope and radiopharmaceutical development, as well as more recent activities.

Calculations for the nuclear reaction cross-sections via α-particle induced reactions on 65Cu to produce impurity free 67Ga for medical applications

Diagnostics field is facilitated with advancements enacted in anatomic imaging (cross-sectional modalities). Radionuclide scans (imaging) escorted by ⁶⁷Ga are extensively beneficial in bone scintigraphy and recognition of prosthetic joint failure. Present work comprises the data concerning ⁶⁷Ga production via α-particle induced nuclear reactions, TTY (thick target yield) and impurity analysis. Experimental measurements regarding ⁶⁷Ga production are analyzed through a comparative study performed with calculations of theoretical model codes (TALYS-1.95, EMPIRE-3.2.3 and ALICE-IPPE). A data set of recommended cross-sections was generated and utilized to deduce TTY. The contribution of radionuclidic impurities is canvassed to suggest an energy region to produce impurity free ⁶⁷Ga for medical applications.

Nuclear model analysis of the 65Cu(α, n)68Ga reaction for the production of 68Ga up to 40 MeV

The charge particle (α) induced reactions on enriched copper (⁶⁵Cu) are investigated for the production of ⁶⁸Ga. The data sets of experimental cross sections are compiled, normalized and nuclear model analysis is done using calculational codes namely, ALICE-IPPE, TALYS 1.95 and EMPIRE 3.2. The theoretical production cross sections via alpha particle induced reactions are calculated to present a set of recommended cross sections. The calculated cross sections are utilized to deduce thick target yield (TTY) for the ⁶⁵Cu (α, n) ⁶⁸Ga reaction. The range of energy for production of ⁶⁸Ga is suggested up to 40 MeV having least contribution of radio-impurities.

Prostate-Specific Membrane Antigen-Targeted Radiopharmaceuticals in Diagnosis and Therapy of Prostate Cancer: Current Status and Future Perspectives

Prostate cancer is the most common cancer to affect men in the United States and the second most common cancer in men worldwide. Prostate-specific membrane antigen (PSMA)-based positron emission tomography (PET) imaging has become increasingly popular as a novel molecular imaging technique capable of improving the clinical management of patients with prostate cancer. To date, several ⁶⁸Ga and ¹⁸F-labeled PSMA-targeted molecules have shown promising results in imaging patients with recurrent prostate cancer using PET/computed tomography (PET/CT). Studies of involving PSMA-targeted radiopharmaceuticals also suggest a higher sensitivity and specificity, along with an improved detection rate over conventional imaging (CT scan and methylene diphosphonate bone scintigraphy) and ¹¹C/¹⁸F-choline PET/CT. In addition, PSMA-617 and PSMA I&T ligands can be labeled with α- and β-emitters (e.g., ²²⁵Ac, ⁹⁰Y, and ¹⁷⁷Lu) and serve as a theranostic tool for patients with metastatic prostate cancer. While the clinical impact of such concept remains to be verified, the preliminary results of PSMA molecular radiotherapy are very encouraging. Herein, we highlighted the current status of development and future perspectives of PSMA-targeted radiopharmaceuticals and their clinical applications.

Production cross sections of 68Ga and radioactive by-products in deuteron-induced reactions on natural zinc

Activation cross sections of the deuteron-induced reactions on natural zinc are studied for the production of the medical radionuclide ⁶⁸Ga. The stacked foil activation method and the γ-ray spectrometry were used. Co-produced radionuclides ^65,66,67Ga, ^63,65,69mZn, ⁶¹Cu, and ⁵⁸Co are also investigated to evaluate amounts of impurities for practical use of ⁶⁸Ga. Physical yields of the radionuclides were deduced from the measured cross sections.

Excitation functions of proton induced reactions of some radioisotopes used in medicine

The main purpose of this study is the investigation of a cross section of proton induced nuclear reactions. The excitation functions of the reactions:56Fe(p,2n)55Co58Fe(p,2n)57Co,111Cd(p,2n)110In,112Cd(p,2n)111In,125Te(p,2n)124I,126Te(p,2n)125I,68Zn(p,2n)67Gawere investigated. These reactions were studied as the resulting radioisotopes are used in medical applications. Theoretical excitation functions have been calculated with TALYS 1.6 nuclear reaction simulation code. The calculated excitation functions are compared with the experimental data.

A technical study to economize the amount of zinc used in the production of radiogallium

For the production of radiogallium, the targets were prepared in two forms, namely, electroplated metal and pressed oxide. The target holder was selected from Cu-metal as a circular disk. The experimental yields of 66,67,68Ga produced from both irradiated natZnO and zinc metal targets are given and compared with the estimated yields as well as with the previously reported values. The ZnO target developed in this work appears to be more convenient and economical for local production of short-lived radiogallium, e.g. 66Ga and 68Ga.

Nuclear data for production and medical application of radionuclides: Present status and future needs

INTRODUCTION

The significance of nuclear data in the choice and medical application of a radionuclide is considered: the decay data determine its suitability for organ imaging or internal therapy and the reaction cross section data allow optimisation of its production route. A brief discussion of reaction cross sections and yields is given.

STANDARD RADIONUCLIDES

The standard SPECT, PET and therapeutic radionuclides are enumerated and their decay and production data are considered. The status of nuclear data is generally good. Some existing discrepancies are outlined. A few promising alternative production routes of ^99mTc and ⁶⁸Ga are discussed.

RESEARCH-ORIENTED RADIONUCLIDES

The increasing significance of non-standard positron emitters in organ imaging and of low-energy highly-ionizing radiation emitters in internal therapy is discussed, their nuclear data are considered and a brief review of their status is presented. Some other related nuclear data issues are also mentioned.

PRODUCTION OF RADIONUCLIDES USING NEWER TECHNOLOGIES

The data needs arising from new directions in radionuclide applications (multimode imaging, theranostic approach, radionanoparticles, etc.) are considered. The future needs of data associated with possible utilization of newer irradiation technologies (intermediate energy cyclotron, high-intensity photon accelerator, spallation neutron source, etc.) are outlined.

CONCLUSION

Except for a few small discrepancies, the available nuclear data are sufficient for routine production and application of radionuclides. Considerable data needs exist for developing novel radionuclides for applications. The developing future technologies for radionuclide production will demand further data-related activities.

Uses of alpha particles, especially in nuclear reaction studies and medical radionuclide production

Alpha particles exhibit three important characteristics: scattering, ionisation and activation. This article briefly discusses those properties and outlines their major applications. Among others, α-particles are used in elemental analysis, investigation and improvement of materials properties, nuclear reaction studies and medical radionuclide production. The latter two topics, dealing with activation of target materials, are treated in some detail in this paper. Measurements of excitation functions of α-particle induced reactions shed some light on their reaction mechanisms, and studies of isomeric cross sections reveal the probability of population of high-spin nuclear levels. Regarding medical radionuclides, an overview is presented of the isotopes commonly produced using α-particle beams. Consideration is also given to some routes which could be potentially useful for production of a few other radionuclides. The significance of α-particle induced reactions to produce a few high-spin isomeric states, decaying by emission of low-energy conversion or Auger electrons, which are of interest in localized internal radiotherapy, is outlined. The α-particle beam, thus broadens the scope of nuclear chemistry research related to development of non-standard positron emitters and therapeutic radionuclides.

The present and future of medical radionuclide production

Medical radionuclide production technology is well established. Both reactors and cyclotrons are utilized for production; the positron emitters, however, are produced exclusively using cyclotrons. A brief survey of the production methods of most commonly used diagnostic and therapeutic radionuclides is given. The emerging radionuclides are considered in more detail. They comprise novel positron emitters and therapeutic radionuclides emitting low-range electrons and α-particles. The possible alternative production routes of a few established radionuclides, like 68Ga and 99mTc, are discussed. The status of standardisation of production data of the commonly used as well as of some emerging radionuclides is briefly mentioned. Some notions on anticipated future trends in the production and application of radionuclides are considered.

New trends in nuclear data research for medical radionuclide production

Nuclear reaction cross section data are of great significance in optimisation of production routes of radionuclides. This article deals with some newer aspects of data research related to production of both standard and novel radionuclides. The recent work to standardise the known data is discussed and new measurements with regard to further optimisation of production routes of some commonly used radionuclides are mentioned. Attempts to increase the specific activity of some reactor-produced radionuclides through the use of charged-particle induced reactions are outlined. The jeopardy in the supply of99mTcviaa fission-produced99Mo/99mTc generator is considered and its possible direct production at a cyclotron is briefly discussed. Regarding the novel radionuclides, development work is presently focussed on non-standard positron emitters for diagnosis and on low-range highly ionising radiation emitters for internal radiotherapy. Recent nuclear reaction cross section measurements related to the production of the two types of radionuclides are briefly reviewed and some anticipated trends in nuclear data research are considered.