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ABSTRACT Molecular imaging markers can be used to differentiate between infection and aseptic inflammation, determine the severity of infection, and monitor treatment responses. One of these markers is ubiquicidin(29-41) (UBI), a cationic peptide fragment that binds to the bacterial membrane wall and is labeled with gallium-68 (68Ga), a positron emitter radioisotope. The use of UBI in positron emission tomography (PET)/computed tomography (CT) for improved detection of lesions has been receiving considerable attention recently. Herein, we report the first case of 68Ga-UBI PET/CT performed in Brazil. The patient was a 39-year-old woman referred for a scan to confirm a clinical suspicion of chronic osteomyelitis of her fractured left tibia. PET images revealed radiotracer uptake near the posterior contour of the tibial fracture focus and the fixation plate, in the soft tissue around the distal half of the tibia, and in the non-consolidated fracture of the left distal fibula. Surgery for local cleaning was performed, and culture of a specimen collected from the surgical site confirmed the presence of Staphylococcus aureus. In the present case, 68Ga-UBI PET/CT, a non-invasive imaging modality, identified the infection foci in vivo, indicating its potential for clinical use.
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Natural products provide a bountiful supply of pharmacologically relevant precursors for the develop-ment of various drug-related molecules,including radiopharmaceuticals.However,current knowledge regarding the importance of natural products in developing new radiopharmaceuticals remains limited.To date,several radionuclides,including gallium-68,technetium-99m,fluorine-18,iodine-131,and iodine-125,have been extensively studied for the synthesis of diagnostic and therapeutic radiophar-maceuticals.The availability of various radiolabeling methods allows the incorporation of these radio-nuclides into bioactive molecules in a practical and efficient manner.Of the radiolabeling methods,direct radioiodination,radiometal complexation,and halogenation are generally suitable for natural products owing to their simplicity and robustness.This review highlights the pharmacological benefits of cur-cumin and its analogs,flavonoids,and marine peptides in treating human pathologies and provides a perspective on the potential use of these bioactive compounds as molecular templates for the design and development of new radiopharmaceuticals.Additionally,this review provides insights into the current strategies for labeling natural products with various radionuclides using either direct or indirect methods.
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Resumen Introducción: En 2009, el Instituto Nacional de Cancerología (INC) elaboró el 177Lu-DOTATATE/TOC. El propósito del estudio fue demostrar la eficacia de estos radiopéptidos en el tratamiento paliativo de pacientes con tumores neuroendocrinos (TNE) avanzados inoperables (metastásicos o localmente avanzados) y en progresión. Métodos: Ensayo clínico abierto fase II de un solo brazo en 13 pacientes adultos con TNE grado 1 o 2, con expresión de receptores de somatostatina en lesiones blanco demostrada por captación Krenning 3 o 4 en 99mTc-HYNIC TOC. Los pacientes fueron tratados con 177Lu-DOTATATE o 177Lu-DOTATOC (según disponibilidad) a una actividad acumulativa proyectada de 600-800 mCi dividida en 3-4 dosis cada 6-9 semanas comenzando siempre con una actividad fija de 200 mCi y dosimetría con la primera dosis. El desenlace primario fue la respuesta objetiva calculada 6 y 12 meses después de la última dosis del tratamiento. Resultados: Se incluyeron 13 pacientes (7 mujeres) de 63 ± 11,6 años con TNE avanzado inoperable y en progresión. La actividad final administrada fue de 800 mCi, 600 mCi, 400 mCi y 200 mCi en 4, 7, 1 y 1 pacientes, respectivamente. La tasa de control de enfermedad a 6 y 12 meses fue de 69,2% y 45,5%, respectivamente, logrando únicamente enfermedad estable. Fallecieron 7 pacientes, 2 de ellos en los primeros 6 meses. La mediana de supervivencia global a partir de la última dosis del radiopéptido fue de 15,7 meses. Conclusiones: Se corroboró la eficacia y la seguridad del tratamiento con los radiopéptidos en NETs avanzados.
Abstract Objectives: The National Cancer Institute first elaborated 177Lu-DOTATATE/TOC in 2009. The purpose of this study was to prove the efficacy of these radiopeptides in the palliative treatment of patients with progressive advanced inoperable neuroendocrine tumors (NETs). Methods: A single-phase phase II open clinical trial was conducted in 13 adult patients with grade 1 y 2 NETs, with expression of somatostatin receptors in target lesions proven by Krenning Score 3 or 4 uptake in 99mTc-HYNIC TOC. Patients were treated with 177Lu-DOTATATE or 177Lu-DOTATOC (depending upon availability) at a projected acumulative activitiy of 600-800 mCi divided into 3-4 doses every 6-9 weeks always beginning with a fixed activity of 200 mCi and dosimetry during the first dose. The primary outcome was objective response to therapy. Results: 13 patients (7 women) aged 63 ± 11.6 years with inoperable advanced NETs were included. The final therapeutic administered activity was 800 mCi, 600 mCi, 400 mCi and 200 mCi in 4, 7, 1 and 1 patients, respectively. The disease control rate at 6 and 12 months was 69.2% and 45.5%, respectively, only obtaining stable disease. Six patients died, 2 of them in the first 6 months. Median overall survival was 15.7 months from the last treatment dose. Conclusions: The efficacy of the treatment with 177Lu-DOTATATE or 177Lu-DOTATOC radiopeptides elaborated in-house was confirmed, becoming a management alternative for patients with advanced NETs.
Subject(s)
Humans , Female , Middle Aged , Palliative Care , Receptors, Somatostatin , Neuroendocrine Tumors , Therapeutics , Dosimetry , MethodsABSTRACT
Resumen Próximo a su 25 aniversario CENTIS reflexiona sobre su quehacer en el contexto de los trastornos que causa la COVID-19. Con ese propósito se examinan el estado de la medicina nuclear y la radiofarmacia antes y durante la epidemia y sus perspectivas de desarrollo. La producción global de radiofármacos continúa siendo una industria consolidada y aunque la pandemia afecta a esta esfera, la presencia de otras enfermedades no cesa, por lo que los servicios de medicina nuclear esenciales y críticos siguen siendo necesarios. Se espera su paulatina reapertura y que se retome con más fuerza la investigación, dado que la COVID-19 es tan compleja y se asocia a tantos factores que constituye, en perspectiva, terreno virgen para las técnicas diagnósticas en medicina nuclear. Ha de permanecer asimismo el papel de los radiofármacos terapéuticos en un grupo importante de enfermedades, en cáncer sobre todo. El Centro de Isótopos pone por ello énfasis tanto en la consolidación, bajo buenas prácticas, de la producción y el suministro de radiofármacos, como en el desarrollo de nuevos productos. Ambos aspectos se basan principalmente en dos radionúclidos: Tc-99m e Y-90.
Abstract Close to its 25th anniversary, CENTIS evaluates its work in the context of the disorders triggered by COVID-19. For this purpose, the situation of nuclear medicine and radiopharmacy, before and during the epidemic and their current development prospects is examined. The production of radiopharmaceuticals continues to be a consolidated global industry and although the pandemic affects this area, the presence of other diseases does not cease, so essential and critical nuclear medicine services are still needed, therefore its gradual reopening is expected. In addition, research will be taken with more strength, given that COVID-19 is so complex and associated with so many factors that it constitutes virgin terrain in perspective for diagnostic techniques in nuclear medicine. The role of therapeutic radiopharmaceuticals in an important set of diseases, especially cancer, will also remain. As a result, the Isotope Center focus its attention under good management practices, on the consolidation of the production and distribution of radiopharmaceuticals and in the development of new products. Both aspects are mainly based on two radionuclides: Tc-99m and Y-90.
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ABSTRACT Objective To expose the current situation of the Brazilian Nuclear Medicine in relation to innovation, taking into account the Intellectual Property protection and the particularities of this field. Methods The number and the origin of patents filings from Brazil, United States and European Patent Convention countries were retrospectively compared in a 20-year period. Results The number of accumulated patents filings of conventional pharmaceuticals was ten times higher compared to the radiopharmaceuticals in the three regions studied. Conclusion The largest number of Brazilian patents filings corresponded to the international patent applications, which is related to the country development conditions, as well as to the difficulties in the process of patent filing.
RESUMO Objetivo Evidenciar a situação atual da Medicina Nuclear brasileira em relação à inovação, considerando a proteção à Propriedade Intelectual e suas particularidades na área. Métodos Foi realizado um levantamento comparativo do número e da origem de depósitos de patentes relacionadas a essa área no Brasil, nos Estados Unidos e em países participantes da European Patent Convention , em um período de 20 anos retroativos. Resultados O número de depósitos acumulados de patentes de medicamentos convencionais foi dez vezes maior quando comparado às famílias relacionadas aos processos que envolvem radiofármacos, nas três regiões estudadas. Conclusão O maior número de depósitos de patentes brasileiras correspondeu aos pedidos de patentes internacionais, refletindo as condições de desenvolvimento do país, bem como as dificuldades encontradas no processo de depósito de uma patente.
Subject(s)
Humans , Patents as Topic/statistics & numerical data , Radiopharmaceuticals , Nuclear Medicine/trends , Patents as Topic/legislation & jurisprudence , United States , Brazil , Inventions/legislation & jurisprudence , Inventions/statistics & numerical dataABSTRACT
Prostate cancer is the most common tumor of the urinary system, and its mortality rate is second only to lung cancer. With the specific and high expression on the surface of prostate cancer cells, prostate-specific membrane antigen (PSMA) has been an ideal theranostic target of prostate cancer with great clinical significance and research value. Positron emission tomography/computed tomography (PET/CT), a new modality of molecular imaging combining functional metabolic information and anatomical structure, provides high diagnostic performance for cancer detection. This paper mainly reviewed recent progress of PSMA inhibitors labeled by positron-emitting radionuclides for early diagnosis, preoperative staging, response assessment, restaging and metastasis detection of prostate cancer.
Subject(s)
Humans , Male , Electrons , Kallikreins , Positron Emission Tomography Computed Tomography , Prostate-Specific Antigen , Prostatic Neoplasms , Diagnostic Imaging , Radioisotopes , ChemistryABSTRACT
@#Megaprosthesis is used to restore the form and function of massive skeletal defects, but it is accompanied by risks of failure, mainly due to perimegaprosthetic infection (PMI). In practice, the diagnosis of infected megaprosthesis among patients with a high index of clinical suspicion, elevated serological markers, and multiple negative or inconclusive imaging can be very challenging and poses a diagnostic conundrum to many orthopaedic surgeons. We present the case of a symptomatic 26-year-old female with large B-cell lymphoma who developed cellulitis with suspected complication of PMI 15 months post-implantation. The combination of advanced nuclear medicine imaging strategies, i.e., 99mTc-besilesomab/ 99mTc-sulfur colloid scintigraphy with hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) scanning helps to characterise and delineate both infections. Invasive procedures such as joint aspiration and biopsy were avoided, and the patient was successfully treated with antibiotics. Hence, we report a case where advanced imaging modalities were decisive in the investigation of PMI.
ABSTRACT
El presente trabajo es una revisión bibliográfica y actualización de los diferentes esquemas terapéuticos aprobados y en estudio, de la enfermedad con metástasis en hueso producto del cáncer de próstata avanzado con la condición de resistente a la castración. Aborda generalidades del cáncer de próstata, los mecanismos por los cuales se vuelve resistente a la castración, la aparición de metástasis óseas, la terapéutica enfocada en terapia antiresortiva, (bifosfonatos e inhibidor del Ligando RANK), radiofármacos, radioterapia y nuevas drogas (Cabozantinib)(au)
This is a literature review and update of the different therapeutic options approved and under study, of bone metastases due to castration resistant prostate cancer. It addresses general information of prostate cancer, the mechanisms by which it becomes resistant to castration, the appearance of bone metastases, treatment focused on antiresorptive therapy (bisphosphonates and RANK Ligand inhibitor), radiopharmaceuticals, radiotherapy and new drugs (Cabozantinib).(au)
Subject(s)
Humans , Male , Prostate/pathology , Radiotherapy , Castration , Radiopharmaceuticals , Diphosphonates/pharmacology , Prostatic Neoplasms, Castration-Resistant/therapy , Neoplasm Metastasis/therapy , Therapeutics , Prostate-Specific Antigen , Reference Drugs , RANK LigandABSTRACT
Abstract It is recognized worldwide that the security of radioactive substances is very important and that the design of facilities where these sources are used and stored must cater for the implementation of good security measures, including the shielding of some treatment and diagnostic rooms. The radiation protection assessment of a nuclear medicine facility consists of the evaluation of the annual effective dose both to workers occupationally exposed and to members of the public. This assessment take into account the radionuclides involved, the facility features, the working procedures, the expected number of patients per year, the administered activity, the distribution of rooms, the thickness and physical materials of walls, floors and ceilings and so on. The assessment results were compared to the design requirements established by the Cuban regulatory body in order to determine whether or not, the nuclear medicine facility complies with those requirements, both for workers and for members of the public. The work presented is useful for facility designer that uses unsealed radionuclides and for the regulatory body.
Resumen A nivel mundial se reconoce que la seguridad de las sustancias radiactivas es muy importante y que el diseño de las instalaciones, donde se utilizan y almacenan las mismas, tienen que implementar medidas de seguridad adecuadas, incluyendo el blindaje de algunos locales de tratamiento y diagnóstico. La evaluación de la protección radiológica de una instalación de medicina nuclear consiste en la determinación de la dosis efectiva anual, tanto para los trabajadores ocupacionalmente expuestos a las radiaciones como para los miembros del público. Esta evaluación tuvo en consideración los radionúclidos involucrados, las características de la instalación, los procedimientos de trabajo, la cantidad de pacientes que se espera tratar o diagnosticar por año, la actividad administrada, la distribución de los locales y el espesor de los materiales empleados en las paredes, pisos y techo, entre otros. Los resultados obtenidos de la evaluación fueron comparados con los requerimientos de diseño establecidos por el órgano regulador cubano para determinar si cumplen o no con tales requerimientos para los trabajadores expuestos y miembros del público. El trabajo presentado resulta útil para diseñadores de instalaciones que utilizan sustancias abiertas y para el órgano regulador.
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Abstract At INFN-LNL (Istituto Nazionale di Fisica Nucleare- Laboratori Nazionali di Legnaro) SPES (Selective Production of Exotic Species), a new facility for the production of radioactive ion beams is being constructed at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro). Radioactive ion beams of neutron-rich nuclei with high purity, in the range of mass between 80 and 160 amu, will be produced by nuclear reactions induced by 40 MeV protons from a cyclotron. The goal of the ISOLPHARM project is to provide a feasibility study for an innovative technology for the production of extremely very high specific activity beta emitting radionuclides as radiopharmaceutical precursors. The ISOL method, adopted in the ISOLPHARM project (a branch of the SPES project), gives the possibility of obtaining pure isobaric beams. In this way, no isotopic contaminations will be present in the beam and afterwards in a proper trapping substrate. The ground-breaking idea of the ISOLPHARM method was granted an International patent (INFN).
Resumen En INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro) SPES (Producción selectiva de especies exóticas), se está construyendo una nueva instalación para la producción de haces de iones radiactivos en INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro). Se producirán haces de iones radiactivos de núcleos ricos en neutrones con alta pureza, en el rango de masa entre 80 y 160 amu, por reacciones nucleares inducidas por protones de 40 MeV de un ciclotrón. El objetivo del proyecto ISOLPHARM es proporcionar un estudio de viabilidad para una tecnología innovadora para la producción de radionúclidos emisores de beta de actividad específica extremadamente alta como precursores radiofarmacéuticos. El método ISOL, adoptado en el proyecto ISOLPHARM (una rama del proyecto SPES), ofrece la posibilidad de obtener haces isobáricos puros. De esta manera, no habrá contaminaciones isotópicas en el haz y luego en un sustrato de atrapamiento adecuado. La idea pionera del método ISOLPHARM recibió una patente internacional (INFN).
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Abstract To present optimized chromatographic systems for radiochemical purity (RCP) evaluation of 99mTc-eluate and 99mTc-radiopharmaceuticals, as well as to assess doses calibrator reliability for routine purposes in hospital radiopharmacies. RCP was determined by different systems and radioactivity was quantified by TLC-scanner, doses calibrator and gamma-counter. Suitable and optimized systems were presented for RCP analyses. No significant differences were observed between radioactivity counting devices and, thus, doses calibrator showed reliability for RCP determination in hospital radiopharmacies.
Subject(s)
Radiochemistry/methods , Radiopharmaceuticals/standards , Chromatography/methods , Radiation DosimetersABSTRACT
Preclinical evaluation is related to the clinical safety of radiopharmaceuticals.There are different research foci on preclinical evaluation of different radiopharmaceuticals.This article summarizes the Food and Drug Administration (FDA) preclinical evaluation guidelines of diagnostic and therapeutic radiopharmaceuticals,in order to provide reference for domestic research and preclinical evaluation of radiopharmaceuticals.
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Radionuclide therapy (RNT) stands on the delivery of radiation to tumors or non-tumor target organs using radiopharmaceuticals that are designed to have specific affinity to targets. RNT is recently called molecular radiotherapy (MRT) by some advocators in order to emphasize its characteristics as radiotherapy and the relevance of dosimetry-guided optimization of treatment. Moreover, RNT requires relevant radiation protection standards because it employs unsealed radionuclides and gives therapeutic radiation doses in humans. On the basis of these radiation protection standards, the development and use of radiopharmaceuticals for combined application through diagnostics and therapeutics lead to theranostic approaches that will enhance the efficacy and safety of treatment by implementing dosimetry-based individualization.
Subject(s)
Humans , Radiation Protection , Radioisotopes , Radiopharmaceuticals , Radiotherapy , Theranostic NanomedicineABSTRACT
Radiopharmaceuticals have been widely used in the diagnosis, treatment and monitoring of diseases, and they play an important role in new drug development. Food and Drug Administration(FDA) has rich experience in the administration of radiopharmaceuticals. This article mainly interprets the regulato-ry policy of FDA for radiopharmaceuticals from the aspects of definition, regulations and registration, trying to provide reference for domestic research of radiopharmaceuticals.
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En el trabajo se examina el mercado internacional de radiofármacos como referencia para caracterizar el escenario cubano. La demanda de radiofármacos de uso diagnóstico y terapéutico aumenta en el mundo alrededor del 10 % cada año. Una medida de ello en el área diagnóstica es el número de cámaras gamma por millón de habitantes, 20 como promedio en los países desarrollados y 0,8 en los países en desarrollo. En la región de América Latina el promedio es de 2.6. En Cuba este indicador ha evolucionado de 1,24 en 2013 hasta 1,78 en la actualidad, con fundada previsión de alcanzar 2,57 en el 2020, incluyendo los tomógrafos de emisión positrónica. Para contribuir a un empleo más eficiente de estas técnicas se introducirán a corto plazo en el área de diagnóstico nuevos radiofármacos a base de para el estudio de enfermedades del sistema nervioso superior, las infecciones y algunos tipos de cáncer. En el área terapéutica se prevé el crecimiento de uso de radiofármacos para el tratamiento de enfermedades tiroideas, del dolor óseo metastásico, del linfoma no Hodgkin y de tumores de origen neuroendocrino. Uno de los radionúclidos considerados de mayor perspectiva en esta línea es el . Todo ello favorece que, como ya tiene lugar en los países desarrollados, los procedimientos de medicina nuclear se incorporen a los sistemas rutinarios de atención de salud
The international radiopharmaceutical market is considered as a reference to characterize the cuban scenario. The demand for diagnostic and therapeutic radiopharmaceuticals increases in the world around 10% each year. An indicator of this increase in the diagnostic area is the number of gamma cameras per million inhabitants: 20 in developed countries and 0,8 in developing countries, on average. In the Latin American region the average is 2,6. In Cuba this indicator has grown from 1.24 in 2013 to 1.78 at present and should reach 2.57 in 2020, including the PET-CT currently under installation. In order to contribute to a more efficient use of these techniques, new radiopharmaceuticals, based on for the diagnosis of diseases of the central nervous system, infections and some types of cancer, will be introduced in the diagnostic area in the short term. In the therapeutic area, the growth of radiopharmaceutical market for the treatment of thyroid diseases, metastatic bone pain, non-Hodgkin's lymphoma and neuroendocrine tumors, is expected. Itrium-90 [] is considered one of the radionuclides with a great perspective in this field. All the above mentioned favors the fact that nuclear medicine procedures are incorporated into routine health-care systems, as already occurred in developed countries
ABSTRACT
En el trabajo se ofrecen argumentos para la selección de un ciclotrón de 18 MeV en protones, en su variante Twin. Estará dedicado solo a reacciones nucleares con dichas partículas a los efectos de asegurar el suministro en Cuba de radionúclidos para la tomografía de emisión positrónica (PET) (fundamentalmente ), así como en perspectiva Iodo- para tomografía de emisión de fotón simple (SPECT). Se dan datos que indican la posibilidad de suministrar -FDG al menos a cinco centros PET. Ello posibilitará el acceso de Cuba a una de las más avanzadas tecnología de imagen, el PET/TAC, con el consiguiente beneficio para la atención a pacientes afectados de cáncer y enfermedades cardiovasculares y neurológicas
The work provides arguments for the selection of 18 MeV cyclotron in protons, in its Twin variant. It will be used only for nuclear reactions with these particles in order to ensure the supply of radionuclides in Cuba, for the positron emission tomography ( mainly) as well as for single photon emission computed tomography (, for example), in the future. Data indicating the possibility of supplying -FDG to at least five PET centers are given. This shall allow Cuba to access the one of the most advanced imaging technology, with the consequent benefit for patients suffering from cancer, cardiovascular and neurological diseases
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En el trabajo se examinan los criterios de calidad de dispersiones radiactivas utilizadas en radiosinovectomía a partir de los requisitos recogidos en la farmacopea para el Fosfato Crómico- de la firma Mallinkrodt, las recomendaciones de uso de radiofármacos registrados de la Asociación Europea de Medicina Nuclear y datos aportados por las firmas comercializadoras. Tomando como base el estudio de dos formulaciones propias de Fosfato Crómico, una marcada con y la otra, con , en las que se estudia la consistencia (reproducibilidad) tanto de la pureza radioquímica como de la distribución de tamaños de partículas, se prueba que el tenor de 5 % de fosfato libre admitido en la formulación de la firma Mallinkrodt y que se extendiera a formas iónicas de otros radiofármacos de matrices diferentes, se debe probablemente al efecto inevitable de la esterilización a vapor sobre la suspensión y de que tanto al momento de decidir sobre el empleo de un lote, como en los requisitos de las farmacopeas, debiera prestarse más atención a la distribución de tamaños por estar más vinculada a la eficacia y seguridad de los radiofármacos
The quality criteria of radioactive dispersions used in radiosynovectomy are examined, taking into account the requirements of the Pharmacopoeia for the Chromic Phosphate P-32 of Mallinckrodt, recommendations for the use of approved radiopharmaceuticals of the European Association of Nuclear Medicine and data provided by others marketing firms. The behavior of two formulations of chromic phosphate, one -labeled and the second -labeled, from the point of view of the consistency (reproducibility) of both the radiochemical purity and the particle size distribution was assayed. It is proven that the presence of 5% of free phosphate admitted in the Mallinckrodt formulation, and extended to the presence of ionic forms of other radiopharmaceuticals of different matrices, is probably due to the inevitable effect of steam sterilization on the suspension. Based on these results and the accumulated clinical experience, it is considered that to establish the quality requirements of the radioactive suspensions for radiosynovectomy, more attention should be paid to the particle size distribution than to the percentage of free ionic forms. The first one is more related to the efficacy and safety of this kind of radiopharmaceuticals
ABSTRACT
Positron emission tomography (PET) has come to the practice of oncology. It is known that 18F-fluorodeoxyglucose (FDG) PET is more sensitive for the assessment of treatment response than conventional imaging. In addition, PET has an advantage in the use of quantitative analysis of the study. Nowadays, various PET parameters are adopted in clinical settings. In addition, a wide range of factors has been known to be associated with FDG uptake. Therefore, there has been a need for standardization and harmonization of protocols and PET parameters. We will introduce PET parameters and discuss major issues in this review.
Subject(s)
Image Processing, Computer-Assisted , Medical Oncology , Positron-Emission Tomography , RadiopharmaceuticalsABSTRACT
ABSTRACT Objective: To evaluate the effects of positive expiratory pressure (PEP) on pulmonary epithelial membrane permeability in healthy subjects. Methods: We evaluated a cohort of 30 healthy subjects (15 males and 15 females) with a mean age of 28.3 ± 5.4 years, a mean FEV1/FVC ratio of 0.89 ± 0.14, and a mean FEV1 of 98.5 ± 13.1% of predicted. Subjects underwent technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA) radioaerosol inhalation lung scintigraphy in two stages: during spontaneous breathing; and while breathing through a PEP mask at one of three PEP levels-10 cmH2O (n = 10), 15 cmH2O (n = 10), and 20 cmH2O (n = 10). The 99mTc-DTPA was nebulized for 3 min, and its clearance was recorded by scintigraphy over a 30-min period during spontaneous breathing and over a 30-min period during breathing through a PEP mask. Results: The pulmonary clearance of 99mTc-DTPA was significantly shorter when PEP was applied-at 10 cmH2O (p = 0.044), 15 cmH2O (p = 0.044), and 20 cmH2O (p = 0.004)-in comparison with that observed during spontaneous breathing. Conclusions: Our findings indicate that PEP, at the levels tested, is able to induce an increase in pulmonary epithelial membrane permeability and lung volume in healthy subjects.
RESUMO Objetivo: Avaliar os efeitos da pressão expiratória positiva (PEP) na permeabilidade da membrana epitelial pulmonar em indivíduos saudáveis. Métodos: Foi avaliada uma coorte de 30 indivíduos saudáveis (15 homens e 15 mulheres), com média de idade de 28,3 ± 5,4 anos, média da relação VEF1/CVF de 0,89 ± 0,14 e média de VEF1 de 98,5 ± 13,1% do previsto. Os indivíduos foram submetidos a cintilografia pulmonar por inalação de radioaerossol de ácido dietilenotriaminopentacético marcado com tecnécio-99m (99mTc-DTPA em inglês) em dois estágios: durante respiração espontânea e durante respiração com uma máscara de PEP de 10 cmH2O (n = 10), 15 cmH2O (n = 10) ou 20 cmH2O (n = 10). O 99mTc-DTPA foi nebulizado por 3 min, e sua depuração foi registrada por cintilografia por um período de 30 min durante respiração espontânea e por um período de 30 min durante a respiração com uma máscara de PEP. Resultados: A depuração pulmonar do 99mTc-DTPA foi significativamente menor quando PEP foi aplicada a 10 cmH2O (p = 0,044), 15 cmH2O (p = 0,044) e 20 cmH2O (p = 0,004), em comparação com a observada durante a respiração espontânea. Conclusões: Nossos achados indicam que o uso de PEP nos níveis testados pode induzir um aumento na permeabilidade da membrana epitelial pulmonar e no volume pulmonar em indivíduos saudáveis.
Subject(s)
Humans , Female , Adult , Lung/metabolism , Positive-Pressure Respiration/methods , Radiopharmaceuticals/pharmacokinetics , Technetium Tc 99m Pentetate/pharmacokinetics , Lung/physiology , Metabolic Clearance Rate , Permeability , Pulmonary Alveoli/metabolism , Radiopharmaceuticals/administration & dosage , Technetium Tc 99m Pentetate/administration & dosageABSTRACT
The positron emitting nuclides were already tried in 1940's as in vivo radio-tracers in the research field of medical biology. In 1976, the discovery of 18FDG with the developing of a positron imaging device, allowed to obtain the image of the human brain by PET technology. Today, 18FDG is widely used in tumour diagnosis by a metabolic trapping mechanism, which is a new concept for functional imaging and makes possible the monitoring of the therapy process. This is first milestone of PET radiopharmaceutical development. The second milestone is the establishment of a molecular imaging method in nuclear medicine and third, is the development of the theragnostic concept of radiopharmaceuticals. At present highlight works are focused in tau protein imaging for Alzheimer disease diagnosis and inflammation imaging
Los núclidos emisores de positrones fueron tratados en 1940 como radiotrazadores in vivo en el campo de las investigaciones biomédicas. En 1976, el descubrimiento de 18FDG, con el desarrollo de un equipo de imagenología positrónica, facilitó la obtención de imágenes del cerebro humano mediante la aplicación de la tecnología PET. En la actualidad, el 18FDG tiene amplia utilización en el diagnóstico de tumores mediante el mecanismo de captura metabólica. Este mecanismo es un concepto nuevo para la obtención de imágenes funcionales lo que permite realizar el monitoreo de los procesos terapéuticos. Este es el primer hito del desarrollo de radiofármacos PET. El segundo hito lo constituye el establecimiento del método de imagen molecular en la medicina nuclear. El tercer hito es el desarrollo del concepto teragnóstico de los radiofármacos. En el momento actual los trabajos principales están enfocados a la imagen de proteínas tau para el diagnóstico de la enfermedad de Alzheimer y las imágenes de inflamaciones