Browsing by Author "Naia, M. Duarte"
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- 45Ti - Titanium: from cyclotron production to potential applications evaluationPublication . Costa, Pedro; Metello, Luís F.; Cunha, Lídia; Lass, Piotr; Currie, Geoff; Johnson, Richard R.; Gelbart, W.; Obermair, J.; Artner, Christoph; Alves, Francisco; Naia, M. DuarteIntroduction: Thousands of radioisotopes are known and virtually all may be artificially produced, however clinical applications of PET imaging are mainly based on 18F, 11C, 13N and 68Ga. This trend could change in the near future, since several groups worldwide are busy developing very promising new entities aiming to contribute for spreading the use and efficacy of clinical diagnostic using Nuclear Medicine imaging techniques. Our group is developing 45Ti-Titanium, assuming it as a potential candidate, since presenting interesting properties: physical half-life of 3.09h, together with relevant chemical properties, that enable radiolabelling with bifunctional chelates, ligands or could even be useful for studies concerning the distribution of new titanium-based chemotherapy drugs or titanium oxide nanoparticles. Considering that data characterizing excitation functions is necessary for radionuclide optimal production, this work aims to disseminate results regarding the determination of excitation function of 45Sc(p,n)45Ti reaction, studied as a potential route to produce 45Ti in low energy cyclotrons.
- Application of Monte Carlo simulation codes to plan an activation experiment in Scandium-45 targetsPublication . Costa, Pedro; Metello, Luís F.; Alves, Francisco; Naia, M. DuarteData characterizing excitation functions of nuclear reactions are necessary for different applications, with the process of radionuclide production being assumed as a relevant example. This is the only way to define and optimize technical parameters involved in such a process. However, nuclear activation experimental studies are sometimes difficult to implement, and care should be taken before its execution, in order to obtain all relevant data, while correctly planning the experiences. In this context, Monte Carlo simulation tools are widely applied to overtake such difficulties. This work describes a case-study aiming to characterize nuclear reactions excitation functions induced by a proton beam and its interaction with a Scandium target – a specific situation that is not yet completely characterized and that might be of relevance, since it could be useful to produce medically relevant radionuclides (eg. Titanium-45).
- Cyclotron produced 45Ti-Titanium: why & how… so WHY NOT?Publication . Costa, Pedro; Metello, Luís F.; Cunha, Lídia; Johnson, Richard R.; Mattei, Lidia; Gelbart, W.; Obermair, J.; Dietl, B.; Nauschnig, R.; Artner, Christoph; Lass, Piotr; Currie, Geoff; Carmo, Sérgio; Alves, Francisco; Naia, M. DuarteThere are many different radioisotopes well known and characterized for medical use, with almost all of them able to be artificially produced. Nevertheless, routine clinical applications of PET imaging are still based on 18F, in excess of 97% of the cases, with 11C, 13N and 68Ga sharing the few remaining situations. This trend could change in the – hopingly near – future, since several groups worldwide are busy developing very promising new processes using less conventional radionuclides, aiming to contribute for spreading the use and efficacy of clinical diagnostic using Nuclear Medicine imaging techniques, evolving more and more in the direction of personalized medicine, an worldwide growing societal request. Our group is busy studying 45Ti, interested by its many interesting properties and assuming it as a high-potential candidate: in fact 45Ti presents a physical half-life of 3.09h (50% higher than 18F) together with relevant chemical properties, that enable radiolabelling with bifunctional chelates, ligands or even to radiolabel titanium (di)oxide nanoparticles. Considering that data characterizing excitation functions are mandatory for radionuclide optimal production, the present work refers to our results regarding the 45Sc(p,n)45Ti nuclear reaction, being studied as a potential route to efficiently produce 45Ti in low energy cyclotrons.
- Cyclotron Production of Unconventional Radionuclides for PET Imaging: the Example of Titanium-45 and Its ApplicationsPublication . Costa, Pedro; Metello, Luís; Alves, Francisco; Naia, M. DuartePositron emitting radionuclides are used to label different compounds, allowing the study of the major biological systems using PET (positron emission tomography) imaging. Although there are several radionuclides suited for PET imaging, routine clinical applications are still based on a restrict group constituted by 18F, 11C, and, more recently, 68Ga. However, with the enlarged availability of low-energy cyclotrons and technical improvements in radionuclide production, the use of unconventional radionuclides is progressively more common. Several examples of unconventional radionuclides for PET imaging are being suggested, and 45Ti could be suggested as a model, due to its interesting properties such as its abundant positron emission (85%), reduced positron energy (β+ endpoint energy = 1040 keV), physical half-life of 3.09 h, and interesting chemical properties. This review aims to introduce the role of cyclotrons in the production of unconventional radionuclides for PET imaging while using 45Ti as an example to explore the potential biomedical applications of those radionuclides in PET imaging
- Espectroscopia gama: desenvolvimento de um software automático de análise e simulaçãoPublication . Costa, Pedro; Metello, Luís F.; Naia, M. DuarteA espectroscopia gama é uma metodologia útil em contextos de identificação, caracterização e quantificação de radiação ionizante. Entre outras, permite a monitorização da radiação ambiental, a detecção e quantificação de impurezas radioactivas ou mesmo o estudo aprofundado de materiais. Deste modo, importa conhecer de forma precisa os espectros característicos dos isótopos radioactivos de interesse. Este trabalho visa apresentar o processo de desenvolvimento de um software, criado com recurso à plataforma MATLAB, capaz de gerar espectros gama completos e/ou de os analisar de forma automática. Até à data, concentraram-se esforços para fontes de 22Na e 60Co e detectores cintiladores de NaI(Tl).
- Experimental results on excitation functions for 45Ti direct production on low energy - medical - cyclotronsPublication . Costa, Pedro; Metello, Luís F.; Cunha, Lídia; Johnson, Richard R.; Gelbart, W.; Obermair, J.; Artner, Christoph; Carmo, Sérgio; Alves, Francisco; Naia, M. Duarte
- PET aplicada à Medicina Moderna: prova de conceito baseada na produção de Titânio-45 ( 45Ti)Publication . Costa, Pedro; Alves, F.; Naia, M. DuarteOs paradigmas modernos da Medicina baseada em Evidência e/ou Ciência, bem como os conceitos relacionados com a Medicina Personalizada, têm levado ao crescente uso de meios complementares de diagnóstico, cada vez mais sensíveis específicos. Nesse contexto, as metodologias de imagem médica têm especial relevo .Dentro destas, vários exemplos podem ser destacados, mas a Medicina Nuclear, baseada no uso de radiofármacos, é especialmente importante ao nível do estudo funcional e molecular dos mais diversos processos patológicos.
- PET imaging using titanium-45: Could it be useful?Publication . Costa, Pedro; Metello, Luís; Alves, F.; Naia, M. DuarteIn the last decade a wider application of positron emission tomography (PET) as one of the most powerful medical imaging technologies was observed. This was largely due to the increased availability of equipment dedicated to production of radioisotopes, mainly due to the installation of low energy cyclotrons in hospitals, research institutes and pharmaceutical industries specialized in radiopharmaceutical production.
- The use of radiolabeled nanoparticles for biomedical imagingPublication . Costa, Pedro; Metello, Luís F.; Alves, Francisco; Naia, M. DuarteIntroduction: In the last years, the practice of medicine is being changing with a special emphasis on the application of technological innovations where medical imaging modalities play an important role. Between several imaging modalities, Molecular Imaging (that is essentially based on Nuclear Medicine) is one of the most interesting solutions. On the other hand, assuming that nanoparticles are being studied as drug delivery systems, its application as vectors for radionuclide-based imaging is in a clear growing.
- Using Monte Carlo to approach 45Ti direct production on low energy - medical - cyclotronsPublication . Costa, Pedro; Cunha, Lídia; Johnson, Richard R.; Gelbart, W.; Artner, Christoph; Alves, Francisco; Naia, M. Duarte; Metello, Luís F.