ESS - MN - Comunicações em eventos científicos
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- 188Re-PEI-MP as potential agent for metabolic radiotherapyPublication . Ferreira, Sara; Abrantes, Ana Margarida; Metello, Luís F.; Zeevart, Jan; Louw, Werner; Dormehl, Irene D.; Botelho, Maria FilomenaIntroduction: 188Re is a promising radionuclide for metabolic therapy because of the emission of high energy beta-particles. The development of watersoluble bone-seeking polymers such as PEI-MP (polyethyleneimine, functionalised with methylphosphonate-groups) that might be labeled with 188Re are recent approaches, with a strong potential for bone cancer treatment. The aim of this study was to evaluate the efficacy of 188Re-PEI-MP, as therapeutic agent for osteosarcoma, through in vitro and in vivo models.
- 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.
- Actual Trends in Nuclear MedicinePublication . Vieira, Domingos; Lemos, Joana; Ferreira, Sara; Metello, Luís F.
- Análise do Potencial do 188Re-PEI-MP como Agente para Radioterapia Metabólica na Terapia de OsteossarcomaPublication . Ferreira, Sara; Abrantes, Ana Margarida; Metello, Luís F.; Zeevart, Jan; Louw, Werner; Dormehl, Irene; Botelho, Maria FilomenaIntrodução e Objectivos: O desenvolvimento do polímero PEI-MP (polietilenoimina funcionalizada com grupos metilfosfonato), possível de radiomarcar com o 188Re (emissor de partículas beta de alta energia), parece poder ter um forte potencial para o tratamento de osteossarcoma. O objectivo deste estudo residiu na avaliação da eficácia do 188Re-PEI-MP como agente terapêutico para o tratamento de osteossarcoma.
- Antioxidant and oxidative stress responses in zebrafish brain after exposure to low doses of ionizing radiationPublication . Lemos, Joana; Guimarães, Laura; Vasconcelos, Vítor; Ponte, Fernanda; Costa, Paulo; Metello, Luís F.; Carvalho, António PauloIntroduction: The use of zebrafish – Danio rerio – has grown considerably, demonstrating the increasing interest to use this model in biomedical research. This is essentially due to the level of homology shared with the human genome, complemented by an easy and reasonably affordable practical side. Hence, this work investigated radiobiological effects of exposure to low doses of ionizing radiation in zebrafish.
- Artifacts in Nuclear Cardiology: Myocardium Perfusion ScintigraphyPublication . Vieira, Domingos
- Assessment of left ventricular dysfunction by three nuclear imaging techniquesPublication . Reis, João; Cunha, Lídia; Costa, Pedro; Neves, Diana; Oliveira, Tânia; Ferrer-Antunes, Ana; Faria-João, Manuel; Metello, Luis[Objectives Nuclear imaging modalities include first pass radionuclide ventriculography (FPRV), multigated radionuclide angiography (MUGA) and gated blood-pool SPECT (GBPS) for monitoring of chemotherapy-related cardiomyopathy. The aim of this work is to correlate between these imaging techniques.]
- Comparative study between two distinct methods for attenuation correction and the use of no-attenuation correction for the assessment of relative uptake of 99mTc-DMSA on pediatric patientsPublication . Nogueira, Fábio; Lemos, Joana; Fonseca, Abigaíl; Cunha, Lídia; Metello, Luís F.Although relative uptake values aren’t the most important objective of a 99mTc-DMSA scan, they are important quantitative information. In most of the dynamic renal scintigraphies attenuation correction is essential if one wants to obtain a reliable result of the quantification process. Although in DMSA scans the absent of significant background and the lesser attenuation in pediatric patients, makes that this attenuation correction techniques are actually not applied. The geometric mean is the most common method, but that includes the acquisition of an anterior (extra) projection, which it is not acquired by a large number of NM departments. This method and the attenuation factors proposed by Tonnesen will be correlated with the absence of attenuation correction procedures. Material and Methods: Images from 20 individuals (aged 3 years +/- 2) were used and the two attenuation correction methods applied. The mean time of acquisition (time post DMSA administration) was 3.5 hours +/- 0.8h. The absence of attenuation correction showed a good correlation with both attenuation methods (r=0.73 +/- 0.11) and the mean difference verified on the uptake values between the different methods were 4 +/- 3. The correlation was higher when the age was lower. The attenuation correction methods correlation was higher between them two than with the “no attenuation correction” method (r=0.82 +/- 0.8), and the mean differences of the uptake values were 2 +/- 2. Conclusion: The decision of not doing any kind of attenuation correction method can be justified by the minor differences verified on the relative kidney uptake values. Nevertheless, if it is recognized that there is a need for an accurate value of the relative kidney uptake, then an attenuation correction method should be used. Attenuation correction factors proposed by Tonnesen can be easily implemented and so become a practical and easy to implement alternative, namely when the anterior projection - needed for the geometric mean methodology – is not acquired.
- Cyclotech - contribution to solve the Technetium shortage by using low energy medical cyclotronsPublication . Metello, Luís F.; Gelbart, W.; Benedict, Malcom; Cunha, Lídia; Alves, Francisco; Johnson, Richard R.This paper presents work in progress, to develop an efficient and economic way to directly produce Technetium 99metastable (99mTc) using low-energy cyclotrons. Its importance is well established and relates with the increased global trouble in delivering 99mTc to Nuclear Medicine Departments relying on this radioisotope. Since the present delivery strategy has clearly demonstrated its intrinsic limits, our group decided to follow a distinct approach that uses the broad distribution of the low energy cyclotrons and the accessibility of Molybdenum 100 (100Mo) as the Target material. This is indeed an important issue to consider, since the system here presented, named CYCLOTECH, it is not based on the use of Highly Enriched (or even Low Enriched) Uranium 235 (235U), so entirely complying with the actual international trends and directives concerning the use of this potential highly critical material. The production technique is based on the nuclear reaction 100Mo (p,2n) 99mTc whose production yields have already been documented. Until this moment two Patent requests have already been submitted (the first at the INPI, in Portugal, and the second at the USPTO, in the USA); others are being prepared for submission on a near future. The object of the CYCLOTECH system is to present 99mTc to Nuclear Medicine radiopharmacists in a routine, reliable and efficient manner that, remaining always flexible, entirely blends with established protocols. To facilitate workflow and Radiation Protection measures, it has been developed a Target Station that can be installed on most of the existing PET cyclotrons and that will tolerate up to 400 μA of beam by allowing the beam to strike the Target material at an adequately oblique angle. The Target Station permits the remote and automatic loading and discharge of the Targets from a carriage of 10 Target bodies. On other hand, several methods of Target material deposition and Target substrates are presented. The object was to create a cost effective means of depositing and intermediate the target material thickness (25 - 100μm) with a minimum of loss on a substrate that is able to easily transport the heat associated with high beam currents. Finally, the separation techniques presented are a combination of both physical and column chemistry. The object was to extract and deliver 99mTc in the identical form now in use in radiopharmacies worldwide. In addition, the Target material is recovered and can be recycled.
- Da Luz à Imagiologia MédicaPublication . Costa, PedroÂmbito: Palestra a convite do Departamento de Física da Universidade de Trás-os-Montes e Alto Douro (ECT - UTAD) Contexto: VII Fórum Física e Sociedade