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1.
Health Phys ; 118(2): 209-214, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31869317

RESUMO

The University of California possesses a large number of Cs irradiators that are used in a wide variety of medical and research applications. The university president made a system-wide decision to reduce the potential threat of malevolent use of Cs by switching wherever feasible to x-ray irradiators over a 3-y period of time. A Radioactive Source Replacement Working Group of involved faculty was formed to study the topic and to make recommendations as to when alternative technologies could offer equivalency. The Working Group concluded that x-ray irradiators could replace Cs irradiators in most applications, with some likely exceptions. They found that the depth dose curve for the 320 kVp x-ray irradiator was found to be nearly identical to that of Cs down to a depth in tissue of 4 cm. It was concluded that x rays (energies ≤320 keV) are more biologically effective than Cs gamma rays, suggesting that lower doses of x rays will be required to achieve the same biological endpoint as Cs gamma rays. A simple conversion factor for equating x-ray effects to Cs effects was not recommended because relative biological effectiveness depends on multiple factors. They concluded that each experiment should be individually calibrated when converting from Cs irradiators to x-ray irradiators. The lessons learned from implementing the project to date have shown the importance of having senior management buy-in, involving the research community in the decision making process and allowing for exceptions where equivalency of Cs to x ray cannot be established.


Assuntos
Radioisótopos de Césio/administração & dosagem , Geradores de Radionuclídeos/instrumentação , Humanos , Eficiência Biológica Relativa , Raios X
2.
Radiat Res ; 192(5): 493-506, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31502907

RESUMO

Irradiators utilizing radioactive cesium-137 (137Cs) or cobalt-60 (60Co) gamma-ray sources have been used for biological applications for many decades. These applications include irradiation of much of the nation's blood supply and radiation biology research. In 2005, the U.S. Nuclear Regulatory Commission was assigned the task of preventing the misuse of radioactive materials by persons with malicious intentions; gamma-ray sources, in particular, were given high priority. This resulted in increased security requirements, including constant surveillance, controlled access and personnel background checks. As a result of such regulations being introduced, organizations considering the purchase of a gamma-ray irradiator for the first time or as a replacement to an existing one due to radioactive decay, are now looking into alternative technologies, primarily an X-ray irradiator. To make an educated decision on whether a particular type of X-ray irradiator is of sufficient equivalency to a particular type of 137Cs irradiator for specific applications, one must rely on relevant published comparison studies from other researchers, or perform the comparison studies on their own. This work focuses on the comparison of the radiation physics aspects of two 137Cs irradiator models and three X-ray irradiator models, for the purpose of determining whether the X-ray irradiator models could validly replace the 137Cs irradiator models for certain applications. Although evaluating the influence of relative biological effectiveness (RBE) differences among irradiators could be part of this study, that has been left for a related publication focused on the theoretical aspects of this topic. These evaluations were performed utilizing 47-g and 120-g tissue-equivalent rodent dosimetry phantoms. Our results indicate that, depending upon the user's dose uncertainty budget and maximum areal density of specimens to be irradiated, the RS 2000 160 kVp X-ray irradiator, X-RAD160 X-ray irradiator or X-RAD320 X-ray irradiator could successfully replace a 137Cs irradiator. Technically, any X-ray irradiator model providing similar irradiation geometry, and average energy similar to or higher than these three X-ray models, could also successfully replace a 137Cs irradiator. The results also reveal that differences in inherent source geometry, field geometry and irradiation geometry can counter some of the influence due to differences in energy spectrum. Our goal is that this publication be used as a guide for other similar studies, providing investigators with information on important details that can make the difference between strong and weak comparison conclusions.


Assuntos
Radioisótopos de Césio/análise , Radioisótopos de Cobalto/química , Radiografia/instrumentação , Radiometria/instrumentação , Geradores de Radionuclídeos/instrumentação , Raios X , Animais , Desenho de Equipamento , Dosimetria Fotográfica , Raios gama , Camundongos , Imagens de Fantasmas , Radiografia/métodos , Radiometria/métodos , Ratos
3.
Nucl Med Biol ; 74-75: 12-18, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31421441

RESUMO

INTRODUCTION: The demand for Gallium-68 (68Ga) for labelling PET radiopharmaceuticals has increased over the past few years. 68Ga is obtained through the decayed parent radionuclide 68Ge using commercial 68Ge/68Ga generators. The principal limitation of commercial 68Ge/68Ga generators is that only a limited and finite quantity of 68Ga (<1.85 GBq at start of synthesis) may be accessed. The focus of this study was to investigate the use of a low energy medical cyclotron for the production of greater quantities of 68Ga and to develop an automated and rapid procedure for processing the product. METHODS: Enriched ZnCl2 was electrodeposited on a platinum backing using a NH4Cl (pH 2-4) buffer. The Zn target was irradiated with GE PETtrace 880 at 35 µA and 14.5 and 12.0 MeV beam energy. The irradiated Zn target was purified using octanol resin on an automated system. RESULTS: Following the described procedure, 68Ga was obtained in 6.30 ±â€¯0.42 GBq after 8.5 min bombardment and with low radionuclidic impurities (66Ga (<0.005%) and 67Ga (<0.09%)). Purification on a single octanol resin gave 82% recovery with resulting [68Ga]GaCl3 obtained in 3.5 mL of 0.2 M HCl. [68Ga]GaCl3 production from irradiation to final product was <45 min. To highlight the utility of the automated procedure, [68Ga]Ga-DOTA-TATE labelling was incorporated to give 1.56 GBq at EOS of the labelled peptide with RCY of >70%. CONCLUSIONS: A straightforward procedure for producing 68Ga on a low energy medical cyclotron was described. Current efforts are focus on high activity production and radiolabelling using solid target produced 68Ga.


Assuntos
Ciclotrons/instrumentação , Radioisótopos de Gálio/metabolismo , Marcação por Isótopo/métodos , Compostos Organometálicos/química , Geradores de Radionuclídeos/instrumentação , Compostos Radiofarmacêuticos/metabolismo , Gálio/química , Radioisótopos de Gálio/isolamento & purificação , Humanos , Compostos Organometálicos/isolamento & purificação , Compostos Organometálicos/metabolismo , Compostos Radiofarmacêuticos/isolamento & purificação
4.
Health Phys ; 117(5): 558-570, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31219892

RESUMO

This paper summarizes about 9 years of effort by Mount Sinai to successfully migrate completely from radioactive irradiators to x-ray irradiators without compromising patient care or research studies. All the effort by Mount Sinai to permanently remove the risk of malicious use of radioactive materials as Radiological Dispersal Device or dirty bomb is reviewed. Due to the unique characteristics of the cesium chloride (CsCl) used in irradiators, it is especially susceptible to be used as a dirty bombs. Mount Sinai originally had four of such irradiators. To reduce and eventually remove the risk of malicious use of radioactive materials, Mount Sinai in New York City has taken several steps. One of such measures was to harden the radioactive irradiators to make the radioactive materials harder to be stolen for malicious purposes. By increasing the delay time, the local law enforcement agency (LLEA) will have more time to stop the intruder. Another measure taken was to implement enhanced security in facilities having radioactive materials. We collaborated with the National Nuclear Security Administration and used state-of-the-art security equipment such as Biometric Access Control and 24/7 video monitoring. In addition, a remote monitoring system with alarms was installed and connected to LLEA for constant monitoring and possible intervention, if necessary, in a timely manner. The other measure taken was to limit the number of people who have access to such radioactive materials. We adopted a single person operator method and reduced the number of people having access from 145 people to only a few people. The adoption of such measures has reduced the risk significantly; however, the best way to remove the permanent risk of these radioactive materials that may be used for a dirty bomb is to use alternative technology to replace these high-activity radioactive sources. In 2013, Mount Sinai purchased its first x-ray irradiator to investigate the feasibility of using x-ray irradiators instead of cesium irradiators for research purposes for cells and small mice. The results from comparison studies were promising, which led to the decision of permanent migration of all cesium irradiators to x-ray irradiators. As of January 2018, Mount Sinai successfully disposed all its Cs irradiators. At this time, Mount Sinai, as one of the largest health care institutions in NY with about 50,000 employees, has migrated completely to alternative technology and removed the risk of malicious use of radioactive materials permanently.


Assuntos
Sangue/efeitos da radiação , Medula Óssea/efeitos da radiação , Encéfalo/efeitos da radiação , Hospitais/normas , Geradores de Radionuclídeos/estatística & dados numéricos , Animais , Radioisótopos de Césio , Humanos , Camundongos , Eficiência Biológica Relativa , Estados Unidos , Raios X
5.
Curr Radiopharm ; 12(3): 187-200, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30924426

RESUMO

BACKGROUND: A significant number of developing countries have no facilities to produce medical radioisotopes and radiopharmaceuticals. OBJECTIVE: In this paper we show that access to life-saving radioisotopes and radiopharmaceuticals and the geographical distribution of corresponding infrastructure is highly unbalanced worldwide. METHODS: We discuss the main issues which need to be addressed in order to establish the production of radioisotopes and radiopharmaceuticals, which are especially important for developing countries as newcomers in the field. The data was gathered from several sources, including databases maintained by the International Atomic Energy Agency (IAEA), World Health Organization (WHO), and other international organizations; personal interactions with representatives in the nuclear medicine field from different regions of the world; and relevant literature. RESULTS: Developing radioisotope and radiopharmaceutical production program and installing corresponding infrastructure requires significant investments, both man-power and financial. Support already exists to help developing countries establish their medical radioisotope production installations from several organizations, such as IAEA. CONCLUSION: This work clearly shows that access to life-saving radioisotopes and the geographical distribution of corresponding infrastructure is highly unbalanced. Technology transfer is important as it not only immediately benefits patients, but also provides employment, economic activity and general prosperity in the region to where the technology transfer is implemented.


Assuntos
Instalações Industriais e de Manufatura , Radioisótopos , Compostos Radiofarmacêuticos , Ciclotrons , Países em Desenvolvimento , Agências Internacionais , Medicina Nuclear , Geradores de Radionuclídeos
6.
Appl Radiat Isot ; 143: 113-122, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30408634

RESUMO

Positron-emitting 72As is the PET imaging counterpart for beta-emitting 77As. Its parent, no carrier added (n.c.a.) 72Se, was produced for a 72Se/72As generator by irradiating an enriched 7°Ge metal-graphite target via the 70Ge(α, 2 n)72Se reaction. Target dissolution used a fast, environmentally friendly method with 93% radioactivity recovery. Chromatographic parameters of the 72Se/72As generator were evaluated, the eluted n.c.a. 72As was characterized with a phantom imaging study, and the previously reported trithiol and aryl-dithiol ligand systems were radiolabeled with the separated n.c.a. 72As in high yield.


Assuntos
Arsênico/isolamento & purificação , Radioisótopos/isolamento & purificação , Geradores de Radionuclídeos , Compostos Radiofarmacêuticos/isolamento & purificação , Radioisótopos de Selênio/isolamento & purificação , Germânio/química , Germânio/isolamento & purificação , Germânio/efeitos da radiação , Humanos , Isótopos/química , Isótopos/isolamento & purificação , Isótopos/efeitos da radiação , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons , Ensaio Radioligante , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/química
7.
J Pharm Biomed Anal ; 163: 39-44, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30278325

RESUMO

68Ga-RM2 is a gastrin releasing peptide receptor (GRPR) antagonist PET (positron emission tomography) radiotracer which is being investigated in clinical trials as a potential prostate cancer imaging agent. Simple, one-step kit formulation of 68Ga-RM2 would facilitate multicentre trials and allow easier integration in hospital radiopharmacy. Herein we report development of three sets of single-vial RM2 cold kits validated for formulation with three respective 68Ge/68Ga generators eluted in 0.6 M, 0.1 M and 0.05 M HCl (hydrochloric acid). Cold kits of varied pH (2, 3, 4 and 5) were prepared using 2 M sodium acetate for three different 68Ge/68Ga generators to determine influence of pH on the radiochemical yield of 68Ga-RM2. Buffer content was optimized with respect to volume of 68GaCl3 eluate to be added (1 mL/2 mL/ 5 mL). Sterility, apyrogenicity and long term stability of cold kits; in vitro and serum stability of 68Ga-RM2 were investigated. In vitro cellular uptake and inhibition studies were performed to demonstrate the specificity of kit-formulated 68Ga-RM2. The radiochemical yield of 68Ga-RM2 formulated from three different generators was observed to be maximum at pH 3 (99 ± 0.5%). Cold kits stored for 6 months at 0 °C also resulted in high radiochemical yield. 68Ga-RM2 exhibited excellent in vitro stability (1 h) and serum stability (1 h). In vitro cellular uptake of 5 ± 0.8% in PC3 cells with >85% inhibition was observed for the 68Ga-RM2 radiotracer indicating its specificity towards GRPR expression. These simple, robust kits shall allow hospitals with different generators to participate in clinical studies of 68Ga-RM2 for screening of GRPR-expressing prostate tumors.


Assuntos
Composição de Medicamentos/métodos , Oligopeptídeos/síntese química , Geradores de Radionuclídeos , Compostos Radiofarmacêuticos/síntese química , Receptores da Bombesina/antagonistas & inibidores , Linhagem Celular Tumoral , Temperatura Baixa , Composição de Medicamentos/instrumentação , Armazenamento de Medicamentos , Humanos , Masculino , Tomografia por Emissão de Pósitrons , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Receptores da Bombesina/metabolismo
9.
Nucl Med Commun ; 39(10): 957-959, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30086075

RESUMO

Rhenium-188 (Re) is a ß, γ emitter and considered a theranostic radionuclide. It is used for bone pain palliation, treatment of unresectable hepatocellular carcinoma, skin keloids, etc. Re perrhenate is eluted from a W/Re generator in large volumes (8-14 ml) of 0.9% normal saline. Concentrating Re to 1-2 ml volume is important for high radiolabelling yield of various Re radiopharmaceuticals, especially when the generator is old. For this, ion exchange column was prepared in-house, and Re was concentrated using silver ion exchange column and QMA cartridge. Re perrhenate eluted in saline was concentrated to 1 ml with more than 99% yield.


Assuntos
Radioisótopos/química , Geradores de Radionuclídeos , Compostos Radiofarmacêuticos/química , Rênio/química , Tungstênio/química , Marcação por Isótopo , Radioquímica
10.
Curr Radiopharm ; 11(3): 180-191, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29766832

RESUMO

OBJECTIVE: Actinium-225, and its daughter Bismuth-213, have great promise in Alpha Immuno Therapy (AIT) for treatment of various disease modalities. Unfortunately, current production levels of actinium-225 do not support broad use of either actinium-225 or bismuth-213 in development or use for disease treatment. Further, the current cost per millicurie is much too high to be sustainable long term. Resolution of both supply and cost issues allows clinical research to proceed through clinical trials and potentially produce one or more effective therapies for cancer or infectious diseases that could benefit the public. METHODS: NorthStar Medical Technologies, LLC, has investigated several routes that could lead to commercial scale production of actinium-225. RESULTS: This article will discuss those efforts and results to date. CONCLUSION: The outlook for future supplies of actinium-225 from multiple sources to support clinical needs is encouraging.


Assuntos
Actínio/química , Radioquímica/métodos , Compostos Radiofarmacêuticos/síntese química , Partículas alfa/uso terapêutico , Geradores de Radionuclídeos
11.
Curr Radiopharm ; 11(3): 173-179, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29669509

RESUMO

BACKGROUND: The radionuclide 225Ac and its daughter 213Bi are among the most interesting alpha emitters being evaluated for incorporation into targeted therapeutic vectors. Global supply of 225Ac is presently insufficient to meet anticipated clinical demand, but the deficiency has been targeted by many research and development efforts, privately and publicly funded. From more than a decade of these endeavors, no single production technology has emerged as a complete solution. In the foreseeable future, global supply of 225Ac will continue to be sourced from a patchwork of production methods and laboratories with a range of radioisotopic purities and achievable yields. Objective and Conclusion: This manuscript attempts to present an overview of availability sources of 225Ac and production methods by which additional supplies might be made available to the community of clinical researchers seeking their application in the treatment of human disease.


Assuntos
Actínio/química , Radioquímica/métodos , Compostos Radiofarmacêuticos/síntese química , Partículas alfa , Geradores de Radionuclídeos
12.
Curr Radiopharm ; 11(3): 215-222, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29683101

RESUMO

BACKGROUND AND OBJECTIVE: The demand for the alpha-emitting radionuclide Actinium-225 (225Ac) for use in radionuclide therapy is growing. Producing 225Ac using high energy linear accelerators, cyclotrons or photoinduction could increase its supply. One potential problem with accelerator produced 225Ac using Thorium-232 targets is the presence in final product of 0.1-0.3% by activity of the long-lived 227Ac impurity at the end of irradiation. It is important to comprehensively evaluate the behavior of accelerator-produced 225Ac in vivo before using it in pre-clinical and clinical applications. METHODS: Biodistribution of accelerator-produced 225Ac in acetate (free) and DOTA complex forms was performed in male and female CD-1 mice. The biodistribution data was used for radiation dosimetry calculations. The toxicity studies of free 225Ac were conducted in CD-1 mice at 1.036 and 2.035 kBq/g body weight. Blood counts, body weight and post-mortem histology were evaluated. RESULTS: In both genders, there was a pronounced uptake of free 225Ac in the liver when compared to 225Ac-DOTA which resulted in 200 and 50 times higher liver radiation dose for free 225Ac in male and female mice, respectively. 227Ac contribution to radiation dose delivered by 225Ac was calculated to be negligible. Mice given free 225Ac did not lose weight, had only transient effect on their blood counts and showed no histological damage to the liver and bone marrow. CONCLUSION: Our biodistribution/dosimetry/toxicity study of accelerator-produced 225Ac demonstrated the patterns very similar to 229Th-derived 225Ac. We conclude that accelerator-produced 225Ac is suitable for the developmental work of targeted radionuclide therapy.


Assuntos
Actínio/farmacologia , Compostos Radiofarmacêuticos/farmacologia , Actínio/química , Actínio/farmacocinética , Partículas alfa/uso terapêutico , Animais , Quelantes , Feminino , Fígado/metabolismo , Masculino , Camundongos , Doses de Radiação , Radiometria , Geradores de Radionuclídeos , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Distribuição Tecidual
13.
Curr Radiopharm ; 11(3): 156-172, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29658444

RESUMO

BACKGROUND: The development of radiopharmaceuticals containing 225Ac for targeted alpha therapy is an active area of academic and commercial research worldwide. OBJECTIVES: Despite promising results from recent clinical trials, 225Ac-radiopharmaceutical development still faces significant challenges that must be overcome to realize the widespread clinical use of 225Ac. Some of these challenges include the limited availability of the isotope, the challenging chemistry required to isolate 225Ac from any co-produced isotopes, and the need for stable targeting systems with high radiolabeling yields. RESULTS: Here we provide a review of available literature pertaining to these challenges in the 225Acradiopharmaceutical field and also provide insight into how performed and planned efforts at TRIUMF - Canada's particle accelerator centre - aim to address these issues.


Assuntos
Actínio/química , Actínio/farmacologia , Partículas alfa/uso terapêutico , Neoplasias/radioterapia , Radioquímica/métodos , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacologia , Humanos , Geradores de Radionuclídeos
14.
Health Phys ; 112(4): 364-375, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28234696

RESUMO

Radiation survey meters and personal dosimeters are typically calibrated in reference neutron fields based on conventional radionuclide sources, such as americium-beryllium (Am-Be) or californium-252 (Cf), either unmodified or heavy-water moderated. However, these calibration neutron fields differ significantly from the workplace fields in which most of these survey meters and dosimeters are being used. Although some detectors are designed to yield an approximately dose-equivalent response over a particular neutron energy range, the response of other detectors is highly dependent upon neutron energy. This, in turn, can result in significant over- or underestimation of the intensity of neutron radiation and/or personal dose equivalent determined in the work environment. The use of simulated workplace neutron calibration fields that more closely match those present at the workplace could improve the accuracy of worker, and workplace, neutron dose assessment. This work provides an overview of the neutron fields found around nuclear power reactors and interim spent fuel storage installations based on available data. The feasibility of producing workplace-like calibration fields in an existing calibration facility has been investigated via Monte Carlo simulations. Several moderating assembly configurations, paired with a neutron generator using the deuterium tritium (D-T) fusion reaction, were explored.


Assuntos
Calibragem/normas , Deutério/normas , Exposição Ocupacional/análise , Exposição à Radiação/análise , Monitoramento de Radiação/normas , Trítio/normas , Deutério/análise , Nêutrons , Exposição Ocupacional/normas , Exposição à Radiação/normas , Monitoramento de Radiação/instrumentação , Geradores de Radionuclídeos/instrumentação , Geradores de Radionuclídeos/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Trítio/análise , Washington
15.
J Nucl Med ; 58(3): 432-437, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28082433

RESUMO

Radiolabeling of the prostate-specific membrane antigen (PSMA) inhibitor Glu-NH-CO-NH-Lys(Ahx) using the 68Ga chelator HBED-CC (PSMAHBED) allows imaging of prostate cancer lesions because of high expression of PSMA in prostate carcinoma cells and in bone metastases and lymph nodes related to the disease. The aim of this work was to optimize labeling of 68Ga-PSMAHBED using the efficient cation-exchange postprocessing of 68Ga as well as the development of a thin-layer chromatography (TLC)-based quality control system. Methods: Labeling was optimized for online ethanol-postprocessed 68Ga eluate investigating various parameters, such as buffer molarity (0.1-1 M), temperature (25°C-90°C), tracer amount (0.11-0.74 nmol), and labeling time. In addition, purification of the crude product was tested. For radio-TLC quality control, various mobile phases were analyzed using silica gel 60 plates and the results were validated using high-performance liquid chromatography. The most superior mobile phases were also applied on instant thin-layer chromatography (ITLC) silica gel plates. Results: Using optimized conditions, labeling yields of more than 95% were obtained within 10 min when ethanol-based postprocessing was applied using PSMAHBED amounts as low as 0.1 nmol. A higher precursor concentration (0.7 nmol) further increased labeling and quantitative yields to more than 98% within 5 min. In clinical routine, patient batches (>200 applications) with radiochemical purity greater than 98% and specific activities of 326 ± 20 MBq/nmol are obtained reproducibly. When TLC quality control was performed on silica gel 60 plates, 4 mobile phases with suitable separation properties and complementary Rf values were identified. Two systems showed equivalent separation on ITLC silica gel plates, with ITLC analysis finished within 5 min, in contrast to 20 min for the TLC system. Labeling of PSMAHBED was optimized for cation-exchange postprocessing methods, ensuring almost quantitative labeling and high nuclide purity of final 68Ga-PSMAHBED, making subsequent purification steps unnecessary. Conclusion: The new radio-TLC method allows quality control in a short time using a fast, reliable, low-cost method with little equipment complexity. Using this approach, the synthesis is easily adopted by automated synthesis modules.


Assuntos
Antígenos de Superfície/química , Contaminação de Medicamentos/prevenção & controle , Radioisótopos de Gálio/química , Glutamato Carboxipeptidase II/química , Marcação por Isótopo/métodos , Compostos Organometálicos/síntese química , Compostos Radiofarmacêuticos/síntese química , Ácido Edético/análogos & derivados , Radioisótopos de Gálio/análise , Radioisótopos de Gálio/normas , Alemanha , Glutamato Carboxipeptidase II/normas , Marcação por Isótopo/normas , Oligopeptídeos , Compostos Organometálicos/análise , Compostos Organometálicos/normas , Controle de Qualidade , Geradores de Radionuclídeos/normas , Compostos Radiofarmacêuticos/análise , Compostos Radiofarmacêuticos/normas
17.
J Labelled Comp Radiopharm ; 60(1): 62-68, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27910132

RESUMO

Gallium-68 radioisotope is an excellent source in clinical positron emission tomography application due to its ease of availability from germanium-68 (68 Ge)/gallium-68 (68 Ga) generator having a shelf life of 1 year. In this paper, a modified method for purification of the primary eluate of 68 Ge-68 Ga generator by using a small cation exchange resin (Dowex-50) column has been described. The breakthrough of 68 Ge before and after purification of 68 Ga eluate was 0.014% and 0.00027%, respectively. The average recovery yield of 68 Ga after purification was 84% ± 8.6% (SD, n = 335). The results of the physiochemical studies confirmed that the 68 Ga-acetate obtained is suitable for labeling of radiopharmaceuticals.


Assuntos
Radioisótopos de Gálio/química , Geradores de Radionuclídeos/instrumentação , Compostos Radiofarmacêuticos/síntese química , Compostos de Estanho/química , Acetatos/química , Técnicas de Química Sintética/instrumentação , Técnicas de Química Sintética/métodos , Compostos Radiofarmacêuticos/química
18.
J Nucl Med ; 58(5): 791-798, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27738005

RESUMO

A single-site prospective open-label clinical study with cyclotron-produced sodium 99mTc-pertechnetate (99mTc-NaTcO4) was performed in patients with indications for a thyroid scan to demonstrate the clinical safety and diagnostic efficacy of the drug and to confirm its equivalence with conventional 99mTc-NaTcO4 eluted from a generator. Methods:99mTc-NaTcO4 was produced from enriched 100Mo (99.815%) with a cyclotron (24 MeV; 2 h of irradiation) or supplied by a commercial manufacturer (bulk vial eluted from a generator). Eleven patients received 325 ± 29 (mean ± SD) MBq of the cyclotron-produced 99mTc-NaTcO4, whereas the age- and sex-matched controls received a comparable amount of the generator-derived tracer. Whole-body and thyroid planar images were obtained for each participant. In addition to the standard-energy window (140.5 keV ± 7.5%), data were acquired in lower-energy (117 keV ± 10%) and higher-energy (170 keV ± 10%) windows. Vital signs and hematologic and biochemical parameters were monitored before and after tracer administration. Results: Cyclotron-produced 99mTc-NaTcO4 showed organ and whole-body distributions identical to those of conventional 99mTc-NaTcO4 and was well tolerated. All images led to a clear final diagnosis. The fact that the number of counts in the higher-energy window was significantly higher for cyclotron-produced 99mTc-NaTcO4 did not influence image quality in the standard-energy window. Image definition in the standard-energy window with cyclotron-produced 99mTc was equivalent to that with generator-eluted 99mTc and had no particular features allowing discrimination between the 99mTc production methods. Conclusion: The systemic distribution, clinical safety, and imaging efficacy of cyclotron-produced 99mTc-NaTcO4 in humans provide supporting evidence for the use of this tracer as an equivalent for generator-eluted 99mTc-NaTcO4 in routine clinical practice.


Assuntos
Ciclotrons/instrumentação , Lesões por Radiação/etiologia , Pertecnetato Tc 99m de Sódio/efeitos adversos , Pertecnetato Tc 99m de Sódio/farmacocinética , Doenças da Glândula Tireoide/diagnóstico por imagem , Doenças da Glândula Tireoide/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Humanos , Marcação por Isótopo/instrumentação , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Especificidade de Órgãos , Lesões por Radiação/diagnóstico , Lesões por Radiação/prevenção & controle , Geradores de Radionuclídeos , Compostos Radiofarmacêuticos/efeitos adversos , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Pertecnetato Tc 99m de Sódio/síntese química , Distribuição Tecidual
19.
J Nucl Med ; 58(3): 514-517, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27688474

RESUMO

99Mo, the parent of the widely used medical isotope 99mTc, is currently produced by irradiation of enriched uranium in nuclear reactors. The supply of this isotope is encumbered by the aging of these reactors and concerns about international transportation and nuclear proliferation. Methods: We report results for the production of 99Mo from the accelerator-driven subcritical fission of an aqueous solution containing low enriched uranium. The predominately fast neutrons generated by impinging high-energy electrons onto a tantalum convertor are moderated to thermal energies to increase fission processes. The separation, recovery, and purification of 99Mo were demonstrated using a recycled uranyl sulfate solution. Conclusion: The 99Mo yield and purity were found to be unaffected by reuse of the previously irradiated and processed uranyl sulfate solution. Results from a 51.8-GBq 99Mo production run are presented.


Assuntos
Molibdênio/química , Fissão Nuclear , Aceleradores de Partículas/instrumentação , Radioisótopos/química , Geradores de Radionuclídeos/instrumentação , Compostos de Urânio/química , Desenho de Equipamento , Análise de Falha de Equipamento , Marcação por Isótopo/instrumentação , Marcação por Isótopo/métodos , Teste de Materiais , Nêutrons , Reatores Nucleares , Projetos Piloto , Doses de Radiação , Compostos Radiofarmacêuticos/síntese química , Compostos de Urânio/efeitos da radiação
20.
Appl Radiat Isot ; 118: 281-289, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27723559

RESUMO

Several terbium isotopes are suited for diagnosis or therapy in nuclear medicine. Tb-155 is of interest for SPECT imaging and/or Auger therapy. High radionuclide purity is mandatory for many applications in medicine. The quantification of the activity of the produced contaminants is therefore as important as that of the radionuclide of interest. The experiments performed at the ARRONAX cyclotron (Nantes, France), using the deuteron beam delivered up to 34MeV, provide an additional measurement of the excitation function of the Gd-nat(d,x)Tb-155 reaction and of the produced terbium and gadolinium contaminants. In this study, we investigate the achievable yield for each radionuclide produced in natural gadolinium as a function of the deuteron energy. Other reactions are discussed in order to define the production route that could provide Tb-155 with a high yield and a high radionuclide purity. This article aims to improve data for the Gd-nat(d,x) reaction and to optimize the irradiation conditions required to produce Tb-155.


Assuntos
Deutério/química , Radioterapia/métodos , Térbio/química , Térbio/uso terapêutico , Nanomedicina Teranóstica/métodos , Doses de Radiação , Geradores de Radionuclídeos , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/uso terapêutico
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