Regulación de los servicios de medicina nuclear: percepción de la problemática y desafíos para el manejo del cáncer en Colombia / Regulation of nuclear medicine services: Perception of the problems and challenges in Colombia for the approach to cancer

Resumen | Introducción. La modificación de las normas sobre medicina nuclear en Colombia ha afectado la administración de la terapia de yodo radioactivo en el tratamiento del cáncer de tiroides. Objetivos. Determinar las áreas de acuerdo en torno al problema, los requisitos actuales y los nuevos exigidos en la normativa para el funcionamiento de los servicios de medicina nuclear. Materiales y métodos. Se hizo un estudio Delphi de dos rondas con cada grupo de expertos, 'clínicos' y 'de entidades reguladoras'. En la primera ronda se exploraron los puntos de vista sobre las implicaciones de la normativa en medicina nuclear y, en la segunda, se calificaron las declaraciones de la primera según su relevancia. Resultados. La problemática de los servicios de medicina nuclear está relacionada con la claridad normativa, y la falta de sinergia y coherencia entre los organismos de inspección, vigilancia y control. Las exigencias del sistema de gestión de desechos requieren una alta inversión económica que puede influir en la oferta del servicio y repercutir en el control integral del cáncer de tiroides. Entre las necesidades presentes y futuras, se encuentran la unificación de criterios entre los auditores, la delimitación de funciones de los actuantes, la asistencia técnica para cumplir con la normativa, y la veeduría a los organismos de inspección, vigilancia y control por parte de los entes reguladores. Conclusión. Los hallazgos del estudio sugieren que los servicios de medicina nuclear atraviesan un momento de múltiples desafíos institucionales, normativos y económicos, que ponen en riesgo el desarrollo y mantenimiento de la medicina nuclear en la atención oncológica.

Abstract | Introduction: Colombia has modified the nuclear medicine norms that impact the administration of radioactive iodine therapy in the treatment of thyroid cancer. Objective: To identify the areas of agreement regarding the issue, as well as the current and emergent requirements associated with the normative for the operation of nuclear medicine services that have an impact on the care of patients with thyroid cancer in Colombia. Materials and methods: We conducted a two-round Delphi study for each expert, clinical, and regulatory group. The first round explored views on the implications of the regulations that apply to nuclear medicine. The second round rated the statements from the first round by their relevance. Results: The issues regarding nuclear medicine services were related to the normative clarity and the lack of synergy and coherence among inspection, surveillance, and control bodies. The demands on the waste management system require a high economic investment that can influence the service offer and have an impact on the integral control of thyroid cancer. Unification of the auditors' criteria, delimitation of the acting agent functions, technical assistance to the services to comply with the normative, and the oversight of the inspection, surveillance, and control bodies by the regulatory entities are among the current and future needs. Conclusions: Our findings suggest that nuclear medicine services are going through a time of multiple institutional, regulatory, and economic challenges that put at risk the development and maintenance of nuclear medicine in cancer care.

Evaluación del riesgo radiológico en la radiosinoviortesis y el tratamiento mielosupresor de la policitemia vera / Radiological risk assessment in radiosynoviorthesis and the myelosupressor treatment of polycythemia vera

Introducción: La aplicación del método de la matriz de riesgo para la evaluación del riesgo radiológico en la medicina permite identificar de manera proactiva debilidades en las etapas del proceso y hacer un plan de acciones de mejora para la seguridad y calidad. Objetivo: Evaluar los riesgos radiológicos de la radiosinoviortesis y el tratamiento mielosupresor con Fósforo-32 de la policitemia vera. Método: Se utilizó el método de matriz de riesgo y se realizó el análisis y tratamiento de los riesgos radiológicos por medio del código cubano SECURE-MR-FMEA 3.0. Resultados: El 17 por ciento del riesgo alto se eliminó con las medidas adicionales adoptadas; predominaron las consecuencias medias para los trabajadores y el público, 30 por ciento y el 14 por ciento, respectivamente. Las defensas más importantes fueron: levantamiento radiológico inicial de las áreas del departamento; revisión independiente del proyecto con las regulaciones de seguridad aplicables; inspección de trabajos de construcción civil y montaje de equipos antes de iniciar la operación del departamento; capacitación de los médicos nucleares en los tratamientos; existencia de protocolos de tratamiento; análisis de lecciones aprendidas de incidentes radiológicos; levantamiento radiológico periódico de las áreas del servicio y procedimiento de emergencia para reducir la dosis en órganos críticos en caso de administración errónea de radiofármacos. Se creó una base de datos de incidentes utilizada como referencia para el modelo utilizado. El factor humano fue la causa mayor de los sucesos radiológicos analizados (88 por ciento). Conclusiones: Estos resultados facilitan la toma de decisiones para el mejor desempeño de la radiosinoviortesis y el tratamiento de la policitemia vera con Fósforo-32 en Cuba. Se sugiere elaborar el plan de mejora de la seguridad con especial atención a las operaciones de administración del radiofármaco en ambos casos.(AU)

Introduction: The application of risk matrix for ionizing radiation medicine allow identify in proactive way the weakness of the process' step, which implies in the design of safety and quality improvement plan for this. Method: Risk matrix method applied for radiosynoviorthesis and the myelosupressor treatment with Phosphorus-32 of polycythemia vera. The Cuban code SECURE-MR-FMEA 3.0 is used. Results: It was eliminated the 17 percent of the high risk with additional measures, and the medium consequences for workers and public are 30 percent and 14 percent, respectively. The most important identified safety measures were the initial radiological monitoring from different nuclear medicine department areas; the project revision based on the applicable safety regulations; a survey of civil construction works and equipment assembly before work began; training of nuclear medicine doctors in related aspects of nuclear medicine treatments; existence of treatment protocols; the analysis of learned lessons from radiological incidents; the periodical radiological monitoring from different services areas and the emergency procedure for the cases of mistake in the radiopharmaceuticals administration. Human factor was the major cause in analyzed radiological events (88 percent). Conclusions: These results facilitate taking decisions for the best performance of radiosynoviorthesis and the myelosupressor treatment with Phosphorus-32 of polycythemia vera in Cuba. It is recommended to elaborate the safety improvement plan from these and focussing in the radiopharmaceutical administration operations in both cases.(AU)

Sinoviortesis con radioisótopos en hemofilia: Experiencia de un centro en Chile / Radionuclide synoviorthesis in hemophilia: experience in 107 patients

Background: In patients with hemophilia, radionuclide synoviorthesis, or the intra-articular injection of a radionuclide to decrease the synovial hypertrophy tissue, aims to decrease or avoid hemarthrosis. Aim: To evaluate the effectiveness of radionuclide synoviorthesis in hemophilia. Material and Methods: Observational retrospective study of the evolution of 107 male patients aged 3 to 54 years who were subjected to radionuclide synoviorthesis between 2007 and 2015. Results: Of 164 treated joints, in 65% treatment was successful, (defined as zero to two hemarthroses and absence of synovitis during the follow up period), in 17% it was partially successful (defined as two or less hemarthroses, but persistence of the synovitis) and failed in 18% of the procedures. No important complications were recorded. Conclusions: Radionuclide synoviorthesis has an overall 82% success rate, is minimally invasive, can be used at any age and is inexpensive We recommend its implementation in Chilean hemophilia treatment centers.

Radionuclide therapy: current status and prospects for internal dosimetry in individualized therapeutic planning

The efficacy and toxicity of radionuclide therapy are believed to be directly related to the radiation doses received by target tissues; however, nuclear medicine therapy continues to be based primarily on the administration of empirical activities to patients and less frequently on the use of internal dosimetry for individual therapeutic planning. This review aimed to critically describe the techniques and clinical evidence of dosimetry as a tool for therapeutic planning and the main limitations to its implementation in clinical practice. The present article is a nonsystematic review of voxel-based dosimetry. Clinical evidence pointing to a correlation between the radiation dose and therapeutic response in various diseases, such as thyroid carcinoma, neuroendocrine tumors and prostate cancer, is reviewed. Its limitations include technical aspects related to image acquisition and processing and the lack of randomized clinical trials demonstrating the impact of dosimetry on patient therapy. A more widespread use of dosimetry in therapeutic planning involves the development of user-friendly dosimetric protocols and confirmation that dose estimation implies good efficacy and low treatment-related toxicity.

Terapia intraperitoneal paliativa en ascitis maligna fîlcrossMark refractaria / Intraperitoneal palliative therapy in refractory malignant ascites

Resumen El tratamiento convencional de la ascitis maligna refractaria es un reto oncológico pues provee mejoría sintomática poco duradera. La terapia intraperitoneal ha sido evaluada principalmente en reportes y series de casos, y en algunos ensayos clínicos, estudiados principalmente en la ascitis por cáncer ovárico y gastrointestinal. Esta terapia incluye: isótopos radioactivos, quimioterapia con hipertermia y sin esta, terapia inmunológica, biológica y otras. Los tratamientos más exitosos con respuestas variables, y aunque la comparación directa no es posible, son: la quimioterapia intraperitoneal hipertérmica (respuesta global entre 85,7% y 100%) y el catumaxomab, que frente a la paracentesis demostró una supervivencia libre de punción de 46 vs 11 días (HR 0,254) y una mediana a la próxima paracentesis de 77 vs 13 días (HR 0,169), con impacto positivo en la calidad de vida, principal fin en el escenario paliativo. La investigación en este campo continúa buscando resultados más duraderos, seguros y costo-efectivos.

Abstract Conventional treatment of refractory malignant ascites is an oncological challenge since it provides little lasting symptomatic improvement. Intraperitoneal therapy, evaluated mainly through series and case reports, and some clinical trials include the use of radioisotopes, chemotherapy, with and without hyperthermia, immunological and biological therapy and others. It has been studied mainly in ascites from ovarian and gastrointestinal cancer. With variable response rates, and although direct comparison is not possible, the most successfully treatments are hyperthermic intraperitoneal chemotherapy (overall response rate between 85.7% and 100%), and catumaxomab, which compared to paracentesis, demonstrated a puncture-free survival of 46 vs. 11 days (HR 0.254) and a median time to next paracentesis of 77 vs. 13 days (HR 0.169). This had a positive impact on quality of life, which is the main goal in the palliative setting. Research in this field continues looking for more lasting, safe, and cost-effective results.

Radioisótopos y Homeopatía, Experiencia de un Médico Mexicano / Radioisotopes and Homeopathy, Experience of a Mexican Doctor

Producto de una conferencia dictada durante la celebración del XXXI Congreso Nacional de Medicina Homeopática (30 de septiembre al 2 de octubre de 2010, en Guanajuato) la autora de este trabajo rememora cómo, desde la década de los cincuenta, en México y el resto del mundo se hablaba de los radioisótopos, de su costosa y complicada fabricación, de los padecimientos y graves lesiones cancerosas que eran capaces de producir, y también de sus posibles usos en la Medicina. Actualmente, los radioisótopos se utilizan para tratar las enfermedades tiroideas, para aliviar el dolor de artritis y el dolor asociado al cáncer de hueso, así como los tumores de hígado y el cáncer de próstata, mama, ojo y cerebro. También son muy eficaces para el diagnóstico de la aterosclerosis coronaria y la necrosis de miocardio Este documento ofrece información por demás relevante acerca de la coincidencia que guarda la medicina homeopática y la terapéutica basada en la acción de los radioisótopos, elementos que, según el doctor Alfonso Reyna Topete, experto en la materia y protagonista de este artículo, cumplen con los mismos principios. (AU)

Result of a conference held in the XXXI National Congress of Homeopathic Medicine (September 30-October 2 2010, Guanajuato) the author of this work recalls how, since the fifties, in Mexico and the rest of the world spoke of radioisotopes, their costly and complicated manufacture, the sufferings and serious cancerous lesions that they were able to produce, and also of their possible uses in Medicine. Currently, radioisotopes are used to treat thyroid diseases, to relieve arthritis pain and pain associated with bone cancer, as well as liver tumors and prostate, breast, eye and brain cancers. They are also very effective for the diagnosis of coronary atherosclerosis and myocardial necrosis. This document offers other relevant information about the coincidence of homeopathic medicine and therapeutics based on the action of radioisotopes, elements that, according to Dr. Alfonso Reyna Topete, expert in the subject and protagonist of this article, comply with the same principles. (AU)

Cambios esperables en el estudio isotópico de laperfusión miocárdica en los pacientes con enfermedadde Chagas y arterias coronarias epicárdicas normales / Suspected changes in isotopic study of myocardial perfusion in patients with Chagas disease and normal epicardial coronary arteries

Resumen La enfermedad de Chagas es una entidad parasitaria ocasionada por el Tripanosoma cruzi muy prevalente en América, especialmente en América Latina. Su fase indeterminada dura entre 10 a 30 años, período en el que los pacientes no presentan síntomas y pueden emigrar a cualquier parte del mundo. La consecuencia más relevante es la cardiopatía chagásica con diferentes manifestaciones. En muchas ocasiones la manifestación inicial de la cardiopatía es la insuficiencia cardiaca sobre un corazón dilatado lo que en ocasiones hace indispensable descartar un componente isquémico. La gammagrafía de perfusión miocárdica es una herramienta muy útil para el estudio de la cardiopatía isquémica, su alta sensibilidad permite observar defectos de perfusión diversos incluso en ausencia de la enfermedad aterosclerótica coronaria. Presentamos el caso de un paciente con dolor torácico y enfermedad de Chagas con diversos defectos de perfusión de origen microvascular en la gammagrafía de perfusión miocárdica con evidencia de las arterias coronarias epicárdicas sanas.

Abstract Chagas disease is a parasitic entity caused by Tripanosoma cruzi with a high prevalence in America, mostly in Latin America. Its indeterminate phase lasts between 10 and 30 years. Within this period patients do not show symptoms and can migrate to anywhere in the world. The most relevant consequence is chagasic cardiomyopathy with different manifestations. Many times the initial sign of this cardiomyopathy is cardiac insufficiency in a dilated heart, which on occasion makes it imperative to rule out an ischemic component. Myocardial perfusión scintigraphies are a useful tool to study myocardial ischemia, their high sensitivity allows to observe diverse perfusion defects, even in the absence of atherosclerotic coronary disease. This study presents the case of a male patient with chest pain and Chagas disease showing multiple perfusion defects of microvascular origin in the myocardial perfusion scintigraphy, evidencing healthy epicardial coronary arteries.

Estudos de aterosclerose experimental utilizando tomografia por emissão de pósitrons ( PET-Scan ) / Studies of experimental atherosclerosis using pósitron emission tomography ( PET-Scan )

A aterosclerose é caracterizada como uma doença imune-inflamatória crônica das artérias devido ao grande acúmulo de lipídios na íntima. Um dos fatores envolvidos na progressão da aterosclerose é a presença de uma subfração de partículas de lipoproteína de baixa densidade (LDL) com um grau mínimo de modificação, denominada LDL eletronegativa [LDL(-)], que possui propriedades pró-inflamatórias, apresenta maior retenção na íntima das artérias e maior tempo de permanência na circulação sanguínea, gerando respostas imuno-inflamatórias. Epítopos de anticorpos monoclonais importantes no reconhecimento das partículas de LDL(-) foram mapeados por phage display, gerando peptídeos mimotopos (P1A3 e P2C7) com potencial para acompanhamento da progressão da aterosclerose, sendo excelentes candidatos como radiotraçadores marcados com emissores de pósitrons para obtenção de imagens moleculares por tomografia por emissão de pósitrons (PET) associada à tomografia computadorizada (PET/CT). O peptídeo P1A3 foi radiomarcado com 64Cu através da complexação com o quelante DOTA, obtendo-se imagens por PET/CT da captação do peptídeo na região do arco aórtico de camundongos knockout para a apolipoproteína E (Apoe-/-) comparados com animais controle sem lesões ateroscleróticas. Antes da obtenção das imagens PET/CT, os peptídeos radiomarcados foram validados através de estudos de estabilidade e biodistribuição, acumulando-se rapidamente nos rins. Também foi sintetizado um nanocluster de ouro, marcado com 64Cu e funcionalizado com P1A3 em sua superfície, observando-se o maior direcionamento dos nanoclusters de ouro ligados ao P1A3 para a região das lesões ateroscleróticas do arco aórtico de camundongos Apoe-/-, comparado ao nanocluster controle. Os peptídeos P1A3 e P2C7 radiomarcados com 68Ga, foram também avaliados por imagens PET/CT em camundongos knockout para o gene do receptor da LDL (LDLr-/-) tratados ou não com dieta hipercolesterolêmica. As imagens PET/CT mostraram que os peptídeos marcados com 68Ga tiveram um aumento de captação na região do arco aórtico de camundongos LDLr-/- hipercolesterolêmicos em relação ao controle. Além disso, P2C7 foi radiomarcado com 99mTc e sua biodistribuição demonstrou uma relação maior de % atividade injetada (AI)/órgão da aorta/coração nos camundongos hipercolesterolêmicos, em concordância com a imagem obtida por SPECT (tomografia computadorizada por emissão de fóton único) que revelou maior captação no arco aórtico

Atherosclerosis is characterized as a chronic immune-inflammatory disease of the large arteries due to the accumulation of lipids in the intima. One of the factors involved in the progression of atherosclerosis is the presence of a subfraction of low-density lipoprotein (LDL) particles with a minimum degree of modification, called electronegative LDL [LDL (-)], which has proinflammatory properties, retention in the intima of the arteries and longer residence time in the blood circulation, generating immune-inflammatory responses. Epitopes of monoclonal antibodies important for the recognition of LDL(-) particles were mapped by phage display, generating mimotope peptides (P1A3 and P2C7) with potential to monitor the progression of atherosclerosis. These peptides are excellent candidates as radiotracers labeled with positron emitters to obtain molecular images by positron emission tomography (PET) associated with computed tomography (PET/CT). The P1A3 peptide was radiolabeled with 64Cu by complexation with the DOTA chelator to obtain PET/CT images of the peptide uptake in the aortic arch of apoliprotein E knockout mice (Apoe-/-) compared to control animals without atherosclerotic lesions. Prior to PET/CT imaging, radiolabeled peptides were validated by stability and biodistribution studies that indicated rapid accumulation in the kidneys. It was also synthesized a gold nanocluster, labeled with 64Cu and functionalized with P1A3 on its surface, observing the greater targeting of gold nanoclusters bound to P1A3 in the region of the atherosclerotic lesions of the aortic arch of Apoe-/- mice, compared to control nanocluster. The P1A3 and P2C7 peptides radiolabeled with 68Ga were also evaluated by PET imaging in LDL receptor gene knockout mice (LDLr-/-) treated or not with a hypercholesterolemic diet. PET/CT images showed that the 68Ga-labeled peptides had increased uptake in aortic arch of LDLr-/- hypercholesterolemic mice in relation to the control. Furthermore, the biodistribution of 99mTc-radiolabeled P2C7 showed a higher %ID (injected dose)/organ ratio of aorta/heart in hypercholesterolemic mice that was in accordance to SPECT (single photon emission computed tomography) imaging showing its higher uptake in the aortic arch

Amiloidosis cardiaca por transtiretina: la gammagrafía mostró el camino / Transthyretin amyloidosis: Scintigraphy showing the way

Fundamento y objetivo: La amiloidosis cardiaca es una enfermedad grave producida por el depósito extracelular a nivel cardiaco de diversas sustancias que se identifican con el análisis de una biopsia endomiocárdica, técnica invasiva, poco accesible y de difícil interpretación. Debido a que las diversas entidades suponen diferente evolución, tratamiento y pronóstico, tiene gran relevancia clínica conocer el subtipo de esta patología. El objetivo es presentar diferentes técnicas diagnósticas no invasivas que nos puedan orientar a sospechar la amiloidosis por transtiretina. Método: Con este caso clínico reflejamos tanto la dificultad para llegar al diagnóstico del subtipo de amiloidosis como la utilidad de las pruebas radiológicas, la gammagrafía y la cardiorresonancia, en el diagnóstico diferencial de amiloidosis cardiaca. Resultados: El intenso depósito cardiaco de forma biventricular en la gammagrafía cardiaca con 99mTc-DPD como el realce tardío biventricular circunferencial en la cardiorresonancia son herramientas muy útiles para orientar hacia el diagnóstico de la amiloidosis por transtiretina.

Background and objetive: Cardiac amyloidosis is a very severe disease caused by extracellular deposition of insoluble fibrils. The gold standard for diagnosing cardiac amyloidosis is an endomyocardial biopsy. This technique is invasive, limited to experienced centers, and thus not widely available. It is required to perform special techniques to precisely determine the amyloid type as the treatment, evolution and prognosis of the disease differs greatly according the type of amyloid present. Method: In this case report we want to present the difficulties for diagnosing the types of amyloid involved in cardiac amyloidosis as well as the usefulness of cardiac MRI for diagnosing cardiac amyloidosis, particularly when performed with the use of the gadolinium as an imaging agent. Results: Biventricular, concentric late gadolinium enhancement on cardiac magnetic resonance and on technetium pyrophosphate scan (99mTc-DPD) showed to be helpful in the diagnosis of senile cardiac amyloidosis transthyrenin variant.

Production, quality control, biodistribution assessment and preliminary dose evaluation of [177Lu]-tetra phenyl porphyrin complex as a possible therapeutic agent / Produção, controle de qualidade, avaliação de biodistribuição e avaliação da dose preliminar de [177Lu] -tetra complexo fenil porfirina como um possível agente terapêutico

Due to interesting therapeutic properties of ¹⁷⁷Lu and tumor avidity of tetraphenyl porphyrins (TPPs), ¹⁷⁷Lu-tetraphenyl porphyrin was developed as a possible therapeutic compound. ¹⁷⁷Lu of 2.6-3 GBq/mg specific activity was obtained by irradiation of natural Lu₂O₃sample with thermal neutron flux of 4 × 10¹³ n.cm^-2.s^-1. Tetraphenyl porphyrin was synthetized and labeled with ¹⁷⁷Lu. Radiochemical purity of the complex was studied using Instant thin layer chromatography (ITLC) method. Stability of the complex was checked in final formulation and human serum for 48 h. The biodistribution of the labeled compound in vital organs of wild-type rats was studied up to 7 d. The absorbed dose of each human organ was calculated by medical internal radiation dose (MIRD) method. A detailed comparative pharmacokinetic study was performed for ¹⁷⁷Lu cation and [¹⁷⁷Lu]-TPP. The complex was prepared with a radiochemical purity: >97±1% and specific activity: 970-1000 MBq/mmol. Biodistribution data and dosimetric results showed that all tissues receive approximately an insignificant absorbed dose due to rapid excretion of the complex through the urinary tract. [¹⁷⁷Lu]-TPP can be an interesting tumor targeting agent due to low liver uptake and very low absorbed dose of approximately 0.036 to the total body of human...

Devido às propriedades interessantes do ¹⁷⁷Lu e da avidez tumoral das tetrafenil porfirinas (TPP), desenvolveu-se a ¹⁷⁷Lu-tetrafenil porfirina como composto terapêutico potencial. ¹⁷⁷Lu de atividade específica de 2,6-3 GBq/mg foi obtido por irradiação de amostra de Lu₂O₃ com fluxo térmico de nêutrons de 4 × 10¹³ n.cm^-2.s^-1. Sintetizou-se a tetrafenil porfirina e marcou-se com ¹⁷⁷Lu. A pureza radioquímica do complexo foi estudada usando método de Cromatografia Instantânea de Camada Delgada ( ITLC). A estabilidade do complexo foi checada na formulação final e no ser humano por 48 h. A biodistribuição do composto marcado em órgãos vitais de ratos do tipo selvagem foi estudada por mais de 7 dias. A dose absorvida para cada órgão humano foi calculada pelo método da Dose Médica de Radiação Interna (MIRD). Estudo farmacocinético comparativo detalhado foi efetuado para o cátion ¹⁷⁷Lu e para o [¹⁷⁷Lu]-TPP. O complexo foi preparado com pureza radioquímica >97±1% e atividade específica de 970-1000 MBq/mmol. Os dados de biodistribuição e os resultados dosimétricos mostraram que todos os tecidos receberam uma dose absorvida aproximadamente insignificante devido à rápida excreção do complexo pelo trato urinário. O [¹⁷⁷Lu]-TPP pode ser um agente interessante de direcionamento do tumor devido à baixa captação pelo fígado e pela dose bem baixa absorvida, de, aproximadamente, 0,036 do corpo humano total...

Radiosinoviortesis con suspensión de fosfato crómico [32p] en pacientes hemofílicos / Synoviorthèse radio-isotopique à phosphate chromique chez les patients atteints d'hémophilie / Use of radiosynoviorthesis with chromic phospate suspensión in hemophilic patients

Introducción: la hemofilia se define como una anomalía congénita, ligada al cromosoma X. Este hecho determina que se manifieste en varones, mientras que las mujeres son solo portadoras de la enfermedad. Objetivo: evaluar la seguridad y efectividad de la radiosinoviortesis con fosfato crómico marcado con [32P] producido por el Centro de Isótopos, en la sinovitis crónica del paciente hemofílico. Métodos: se incluyeron aquellos pacientes que presentaban más de tres hemartrosis en un mes. Previo consentimiento de los pacientes, se les inyectó 1 mCi del isótopo en la articulación afectada. Fue monitoreada la migración del radiofármaco 10 min después del proceder y en los días 1, 7 y 30 posteriores al tratamiento. También se realizaron estudios hematológicos y citogenéticos antes del tratamiento y un año después de este. Se determinó la frecuencia de sangrado, el dolor y el consumo de factor antihemofílico. Fueron tratadas 10 rodillas en 9 pacientes (hemofilia A, 88,9 por ciento y hemofilia B, 11,1 por ciento). La edad media de los enfermos fue de 36,3 años con un rango entre 23-59 años. Resultados: no se observó fuga articular significativa, ni cambios hematológicos. El estudio cromosómico fue normal en los pacientes estudiados. Antes de la radiosinoviortesis con 32P, los pacientes presentaron una tasa de sangrado de 10,3 veces por mes (rango 7-13, SD ± 2,2). La frecuencia de sangrado después de realizado el proceder disminuyó a 0,8 (P< 0,0001) en los 12 meses posteriores a la radiosinoviortesis (rango 0-4, SD ± 1,23). Conclusiones: la radiosinoviortesis con fosfato crómico es un procedimiento seguro y efectivo en la sinovitis crónica del paciente hemofílico(AU)

Introduction: hemophilia is defined as an X chromosome-linked congenital anomaly that mainly occurs in males whereas females just carry the disease. Objective: to evaluate the safety and the effectiveness of radiosynoviorthesis using 32P chromic phosphate manufactured by CENTIS to treat the chronic synovitis in hemophilic patients. Methods: the patients who presented with more than three hemarthoses in a month were included in the study. After the patients' consent, they were injected 1 mCi of the radionuclide in the affected joint. The migration of the radiopharmaceutical was then monitored 10 minutes after the procedure as well as 1, 7 and 30 days following the treatment. Hematological and cytogenetic studies were also performed before and one year after the treatment. The bleeding frequency rate, pain and the consumption of anti-hemophilic factor were determined. Ten knees from 9 patients received this therapy (hemophilia A in 88.9 pecent and hemophilia B in 11.1 percent). The average age of patients was 36.3 years, with a range of 23 to 59 years. Results: there was neither significant joint leakage nor hematological change. The chromosomal study yielded normal values. Before the radiosynoviothesis with 32P, the patients exhibited a bleeding frequency rate of 10.3 times a month (range 7-13, SD ± 2.2), but this rate lowered to 0.8 (P< 0.0001) within the 12 months after the procedure (range 0-4, SD ± 1.23). Conclusions: radiosynoviorthesis with chromic phosphate is a safe effective procedure to treat chronic synovitis in the hemophilic patient(AU)

Introduction: l'hémophilie est définie comme une anomalie congénitale associée au chromosome X. Ce sont donc les hommes qui se rendent malades, tandis que les femmes ne sont que porteuses de la maladie. Objectif: le but de ce travail est d'évaluer la sécurité et l'efficacité de la synoviorthèse radio-isotopique (SRI) à phosphate ( 32P) chromique (produit par le CENTIS, La Havane, Cuba) chez les patients hémophiliques atteints de synovite chronique. Méthodes: les patients ayant plus de trois hémarthroses en un seul mois ont été inclus dans cette étude. Avec le consentement préalable de chaque patient, 1 mCi de cet isotope a été injecté dans l'articulation affectée. On a commencé à surveiller le trajet du radio-isotope 10 min après le procédé, ainsi qu'aux 1e, 7e, et 30e jours. On a également réalisé des tests hématologiques et cytogénétiques avant et après un an de traitement. Les fréquences de l'hémorragie, de la douleur et de l'administration du facteur anti-hémophilique ont été déterminées. Neuf patients (10 genoux) ont été traités (hémophilie A, 88.9 pourcent et hémophilie B, 11.1 pourcent). L'âge moyen des malades a été 36.3 ans avec un rang de 23-59 ans. Résultats: on n'a observé ni fuite articulaire significative ni changements hématologiques; le test chromosomique des patients étudiés a été normal. Avant la SRI à 32P, les patients ont présenté un taux d'hémorragie de 10.3 fois par mois (rang de 7-13, DS ± 2.2). La fréquence de l'hémorragie après le procédé a diminué à 0.8 (P< 0.0001) en 12 mois (rang de 0-4, DS ± 1.23). Conclusions: la SRI à phosphate chromique est une technique sure et effective pour le traitement de la synovite chronique du patient atteint d'hémophilie(AU)

Resultados de SPECT miocárdico y eventos cardiovasculares en dos servicios de Medicina nuclear de Bogotá durante 2011 a 2012 / Myocardial SPECT results and cardiovascular events in two nuclear medicine departments in Bogota from 2011 to 2012

Objective: This study sought to determine the relationship between the results obtained from myocardial SPECT with pharmacologic stress with dipyridamole and the development of major cardiovascular events in the follow-up of patients treated at two nuclear medicine departments in Bogota, Colombia. Materials and methods: 183 patients undergoing myocardial SPECT with pharmacological stress with dipyridamole between November 2011 and April 2012 with a twelve month follow-up, were included. The relationship between the development of major cardiovascular events and the functional or perfusion results of the myocardial SPECT were analyzed. Results: 14 patients from the 154 who completed the follow-up, developed cardiovascular events. Patients with abnormal studies had higher number of events (13 vs 1. p = 0.019) compared to those with normal studies. The results of abnormal perfusion were associated with higher incidence of events (15.19%). Conclusions: A normal myocardial SPECT study is related to reduced incidence of major cardiovascular events in a one year follow-up, even in patients with high-risk clinical characteristics.

Objective: This study sought to determine the relationship between the results obtained from myocardial SPECT with pharmacologic stress with dipyridamole and the development of major cardiovascular events in the follow-up of patients treated at two nuclear medicine departments in Bogota, Colombia. Materials and methods: 183 patients undergoing myocardial SPECT with pharmacological stress with dipyridamole between November 2011 and April 2012 with a twelve month follow-up, were included. The relationship between the development of major cardiovascular events and the functional or perfusion results of the myocardial SPECT were analyzed. Results: 14 patients from the 154 who completed the follow-up, developed cardiovascular events. Patients with abnormal studies had higher number of events (13 vs 1. p = 0.019) compared to those with normal studies. The results of abnormal perfusion were associated with higher incidence of events (15.19%). Conclusions: A normal myocardial SPECT study is related to reduced incidence of major cardiovascular events in a one year follow-up, even in patients with high-risk clinical characteristics.

Radioisótopo e modelagem matemática na avaliação da suplementação de fitase em dietas para suínos em crescimento / Radioisotope and mathematical modeling in the assessment of supplementation of Phytase in diets for growing pigs

O objetivo deste trabalho foi avaliar os efeitos da inclusão de níveis crescentes de enzima fitase em dietas para suínos em fase de crescimento, por meio do uso de modelagem matemática. Foram utilizados dados de 20 leitões mestiços, machos castrados, pesando em média, 26,8kg. Os animais ficaram alojados em gaiolas metabólicas individuais para a coleta de fezes e urina, onde permaneceram por um período de 17 dias. Utilizou-se o delineamento experimental de blocos ao acaso, com cinco tratamentos e quatro repetições. A dieta experimental fornecida aos leitões foi à base de milho e farelo de soja, suplementada com cinco níveis crescentes de enzima fitase (0, 250, 500, 750 e 1000UF/kg), correspondendo a 0; 0,01; 0,02; 0,03 e 0,04%, respectivamente. As variáveis avaliadas foram: ingestão, excreção, fluxo e refluxo do P nos compartimentos (trato digestivo, corrente sanguínea, tecidos moles e ossos). A enzima fitase não interferiu no P consumido (P>0,05 (F10), no P excretado na urina (F02), no fluxo e refluxo do P nos ossos (F32 e F23) e nos tecidos moles (F42 e F24), entretanto observou-se redução no P excretado nas fezes (F01) em 8,92%; 26,76%; 22,53% e 28,64% para os níveis 0, 250, 500, 750 e 1000UF/kg, respectivamente, e efeito linear positivo para o P endógeno (F12). Pode-se utilizar dietas à base de milho e farelo de soja com 50% de P por fosfato bicálcico, adicionando-se 250UF/kg de dieta para suínos em crescimento, o que reduz em 27% as excreções de P nas fezes.

The purpose of this study was to evaluate the effects of including increasing levels of phytase enzyme in pig diets for growing pigs, using the mathematical model. Data from 20 crossbred male piglets, castrated and weighing 26.80 kg on average was used. The animals were housed in individual metabolic cages to collect feces and urine in a 17 day period. A randomized block experimental design containing five treatments and four repetitions was used. The experimental diet provided to piglets contained corn and soybean and was supplemented with five increasing levels of phytase enzyme (0, 250, 500, 750 and 1000 UF/kg), corresponding to 0.00 %, 0.01 %, 0.02 %, 0.03 % and 0.04 % respectively. The variables evaluated were: intake, excretion, output flow of P in the digestive tract, bloodstream, bones and soft tissues. The phytase enzyme did not affect the P intake (P>0.05 (F 10), the P excreted in urine (F02) and the output flow of P in the bones (F32 e F23) and soft tissue (F42 e F24) , however, there was a reduction in P excreted in feces (F01) of 8.92 %, 26.76 %, 22.53 % and 28.64 % to the levels 0, 250, 500, 750 e 1000UF/kg, respectively and showed a positive linear effect (P<0.08) for the endogenous P (F12) . Corn and soybean meal based diets can be used with 50% of P by dicalcium phosphate, adding 250UF/kg diet for growing pigs, and may cause a reduction of 27 % of P excretion in feces.

Biodistribution of meglumine antimoniate in healthy and Leishmania (Leishmania) infantum chagasi-infected BALB/c mice

Pentavalent antimonials such as meglumine antimoniate (MA) are the primary treatments for leishmaniasis, a complex disease caused by protozoan parasites of the genus Leishmania . Despite over 70 years of clinical use, their mechanisms of action, toxicity and pharmacokinetics have not been fully elucidated. Radiotracer studies performed on animals have the potential to play a major role in pharmaceutical development. The aims of this study were to prepare an antimony radiotracer by neutron irradiation of MA and to determine the biodistribution of MA in healthy and Leishmania (Leishmania) infantum chagasi-infected mice. MA (Glucantime(r)) was neutron irradiated inside the IEA-R1 nuclear reactor, producing two radioisotopes, 122Sb and 124Sb, with high radionuclidic purity and good specific activity. This irradiated compound presented anti-leishmanial activity similar to that of non-irradiated MA in both in vitro and in vivo evaluations. In the biodistribution studies, healthy mice showed higher uptake of antimony in the liver than infected mice and elimination occurred primarily through biliary excretion, with a small proportion of the drug excreted by the kidneys. The serum kinetic curve was bi-exponential, with two compartments: the central compartment and another compartment associated with drug excretion. Radiotracers, which can be easily produced by neutron irradiation, were demonstrated to be an interesting tool for answering several questions regarding antimonial pharmacokinetics and chemotherapy.

Control de calidad interno de la determinación de folatos séricos por metodologías inmunométricas / Internal quality control of the determination of serum folate by immunometric methods

Comparar dos tecnologías de determinación de folatos séricos en mujeres en edad fértil, que comparten el mismo principio y evidenciar la mejora tecnológica, así como, la validez de los resultados. Materiales y métodos: Los datos provienen de tres estudios poblacionales y cuatro de comunidades centinela. El tamaño de muestra se calculó usando el procedimiento propuesto por Fleiss (1981) y se aplicó un diseño de muestra multi-etapa y se incorporó en el análisis estadístico un ajuste por efecto de diseño de 1,5. Resultados: Desde la perspectiva del laboratorio se nota una mejora en la ...

Metástases hepáticas de insulinoma 14 anos após a ressecção do turmor primário / Liver metástases 14 years after the insulinoma resection of the primary tumor

A Insulinoma é um tumor que pertence ao grupo de tumores neuroendócrinos do pâncreas. Sua incidência é rara (1-4 casos por milhão de pessoas por ano). A ressecção cirúrgica é o tratamento de escolha para o tumor localizado no pâncreas. Cerca de 90% dos tumores Exibiram um benigno comportamento e menos de 10% dos pacientes podem apresentar doença metastática, principalmente no fígado e nos linfonodos regionais. Na doença metastática, o controle da hipoglicemia, frequentemente grave e persistente, é o principal desafio para o médico da equipe que cuida do paciente. Descrevemos o caso de um paciente de 61 anos, que foi encaminhado à Unidade de Gastroenterologia no HC-UFU (Universidade Federal de Uberlândia), em julho de 2011, para a investigação de tumores no fígado, evidenciado na ultrassonografia abdominal. Também apresentou um histórico de episódios frequentes de diminuição de nível de consciência e comportamento anormal, além de 3 episódios de convulsões nos últimos 10 meses. Como história pessoal, a paciente relatou ter sido submetida a uma ressecção cirúrgica do nódulo no pâncreas em 1997 por episódio de hipoglicemia desde 1995, que se resolveu após a cirurgia. Ela relatou diagnóstico de hipertensão e de diabetes mellitus desde 2003, quando começou a usar anti-hipertensivos e metformina, sendo que o uso desta foi suspenso por 2 anos para a normalização da glicemia. No exame físico, ficou evidenciada apenas uma leve hepatomegalia,sem outras normalidades. Ela também teve glicemia no sangue de 51 mg/dl e diminuição do nível de consciência depois de um curto período de jejum. Foi necessária a aplicação de glicose em bomba de infusão no dia da internação para a enfermaria. Na revisão, verificou-se nos registros médicos da paciente que, em 1997, ela foi submetida à ressecção de um tumor no pâncreas por enucleação de 5 cm (a cabeça do pâncreas), com histopatologia que confirmou o diagnóstico de insulinoma. Para o diagnóstico em laboratório, a paciente foi mantida em jejum, com suspensão de infusão de glicose e, após 9 minutos, verificou-se a redução da consciência; em seguida, foi recolhida uma amostra periférica de insulina no sangue, de glicose, de dosagem de sulfonilureia, proinsulina e C-peptídeo. Os testes mostraram altos níveis de insulina, pró-insulina, além do peptídeo C alto dosagem de sulfonilureias negativa. A proporção de insulina / glicose de 5,95 era baseada em critérios laboratoriais de hiperinsulinismo. A TC de abdômen evidenciou múltiplos nódulos sugestivos de metástase do fígado e pâncreas normal. Em seguida, uma biópsia foi realizada da maior lesão hepática, guiada por ultrassom. O estudo imuno-histoquímico da lesão confirmou um tumor neuroendócrino de origem pancreática, sugestivo bem diferenciado de insulinoma. A lâmina de 1997 também foi revisada com estudo imuno-histoquímica e era consistente com o diagnóstico de lesões do fígado. No fim do estágio da doença, a paciente foi submetida a exame de cintilografia rotulados com 111In-DTPA-octreotid a, que mostrou captação do traçador em zonas múltiplas do fígado, sem evidências de lesões extra-hepáticas. Eles também foram condenados testes de laboratório que excluída a associação com neoplasia endócrina múltipla síndrome tipo 1. Foram prescritos propranolol, verapamil e hidroclorotiazida, numa tentativa de melhorar os níveis de glicemia, além de uma dose de depósito de octreotida (octreotida LAR) com boa resposta clínica, com a possível diminuição gradual em infusão de glicose e suspenso em 25 dias de aplicação da droga. A paciente está recebendo uma dose mensal de octreotida LAR. A paciente permanece em bom estado geral, sem queixas, apesar de envolvimento hepático difuso por lesões. Mantém normais testes laboratoriais (AST, ALT, fosfatase alcalina, Gama GT, bilirrubina e albumina TAP). Mantém os exames ambulatoriais regulares.

Insulinoma is a tumor that belongs to the group of neuroendocrine tumors of the pancreas. Its incidence is rare (1-4 cases per million people per year). Surgical resection is the treatment of choice for localized tumor in the pancreas. About 90% of the tumors exhibited a benign behavior and less than 10% of patients may show metastatic disease (mainly in liver and regional lymph nodes). In metastatic disease, the control of hypoglycemia, often serious and persistent is the key challenge for the medical team that cares of the patient. We describe a case of a patient of 61 years that was referred to the gastroenterology unit on HC-UFU in July 2011 for investigation of liver tumors (evidenced in abdominal ultrasonography)also presenting a history of frequent episodes of decreased level of consciousness and abnormal behavior, in addition to 3 episodes of seizures in the past 10 months. As personal history, the patient reported having undergone a surgical resection of the nodule in the pancreas in 1997 by hypoglycemic episodes since 1995 and which resolved after surgery. He also reported diagnoses of hypertension and diabetes mellitus since 2003, when it began using antihypertensives and metformin, with the use of this suspended for 2 years for normalization of glycemia. On arrival it was evident on physical examination only a mild hepatomegaly without other abnormalities. She also had blood glucose of 51 mg / dl and decreased level of consciousness after short periods of fasting. It required glucose infusion pump on the day of admission to the ward. In reviewing the medical records of the patient, it was found that in 1997 the patient underwent resection of a pancreatic tumor by enucleation (the head of the pancreas) of 5 cm, with histopathology confirmed the diagnosis of Insulinoma. For laboratory diagnosis, the patient was kept fasting, with suspension of glucose infusion and after 9 minutes showed decreased level of consciousness, and then collected in a sample of peripheral blood insulin,glucose; dosage of sulfonylurea; proinsulin and C-peptide The tests showed high levels of insulin, pro-insulin and C peptide Blood glucose was low in value and dosage of sulfonylurea was negative. The ratio insulin / glucose of 5.95 was laboratory criteria of hyperinsulinism. A CT of the abdomen showed multiple nodules suggestive of liver metastasis and normal pancreas. Then a biopsy was performed of the largest lesion liver guided by ultrasound. The immunohistochemical study of the lesion confirmed a neuroendocrine tumor of pancreatic origin suggestive of well-differentiated insulinoma. The blade of 1997 was also reviewed with immunohistochemical study and was consistent with the diagnosis of liver lesions. In order to stage the disease, the patient underwent the examination of scintigraphy labeled with 111In-DTPA-Octreotide, which showed tracer uptake in multiple areas of the liver, without evidence of extrahepatic lesions. They were also ordered laboratory tests that excluded the association with multiple endocrine neoplasia syndrome type 1. We prescribed propranolol, verapamil and hydrochlorothiazide in an attempt to improve blood glucose levels, plus a dose of Octreotide depot (Octreotide LAR) with good clinical response, with the possible gradual decrease in glucose infusion and suspended in 25 ° day application of the drug. The patient is receiving a monthly dose of Octreotide LAR. The patient remains in good condition overall, no complaints, despite diffuse liver involvement by injuries, maintains normal laboratory tests (AST, ALT, alkaline phosphatase, Gamma GT, bilirubin, and albumin TAP). Keeps regular outpatient follow.

Fosfato de cromo (III) marcado con diferentes radionúclidos para uso en radiosinoviortesis / Chromium (III) labelled with several radionuclidesphosphate for use in radiosynoviothersis

Introducción: la radiosinoviortesis se utiliza en el tratamiento de la sinovitis crónica, complicación frecuente en enfermedades sistémicas como artritis reumatoide y hemofilia. En la práctica clínica internacional se emplean diferentes coloides y suspensiones radiactivas, pero su número es reducido y su disponibilidad limitada. Objetivo: obtención y caracterización físico-química de suspensiones de fosfato de cromo (III) marcadas con radionúclidos como potenciales radiofármacos para uso en radiosinoviortesis. Métodos: las suspensiones se obtuvieron por síntesis química, los radionúclidos se añadieron al inicio de la reacción o después de finalizada esta. El tamaño de partículas se estimó mediante microscopia óptica y filtración por membranas. Asimismo se evaluó por espectrofotometría la estabilidad de la suspensión al ser resuspendida en distintos medios. La pureza radioquímica se determinó por cromatografía de papel. Resultados: se obtuvo y caracterizó una suspensión de fosfato de cromo (III). El producto obtenido presentó un tamaño de partículas predominante entre 0,8-5 µm y que al ser suspendidas en solución de gelatina al 2 por ciento en tampón acetato 1 mg/mL no sedimentó en menos de 3 h. Se estableció la tecnología para la obtención de formulaciones de fosfato de cromo (III) marcado con 32P e 90Y y se demostró la factibilidad de marcar la suspensión obtenida con otros radionúclidos trivalentes como 177Lu y 68Ga. Conclusiones: los resultados permiten considerar al fosfato de cromo (III) una suspensión base para la obtención de radiofármacos para uso en radiosinoviortesis en diferentes articulaciones, en función de las características físico-nucleares de los radionúclidos que se empleen

Introduction: radiosynoviorthesis is used in treating chronic synovitis, a frequent complication of some systemic diseases as rheumatoid arthritis and hemophilia. There are different colloids and radioactive suspensions recommended in the international clinical practice, but the number is reduced and the availability limited. Objective: obtaining and physical-chemical characterization of suspensions of chromium phosphate (III) labeled with several radionuclides as potential radiopharmaceuticals for using in radiosynoviorthesis. Methods: the suspensions were obtained by chemical synthesis. Radionuclides were added at the beginning or after concluding the reaction. The particle size was estimated by means of optic microscopy and membrane filtration. Similarly, the stability of suspension when re-suspended in several media was evaluated by spectrophotometry. The radiochemical purity was determined by paper chromatography. Results: a suspension of chromium (III) phosphate was obtained and characterized. It was found that the obtained product had a predominant particle size range of 0,8 to 5 µm and that when suspended in 2 percent gelatin solution in 1mg/ml acetate buffer, it settled in no less than 3 hours. Technologies for the preparation of radiopharmaceuticals of Chromium (III) Phosphate labeled with 32P and 90Y were described. There was demonstrated the feasibility of labeling the obtained suspension with other trivalent radionuclides such as 177Lu and 68Ga. Conclusions: the results allow considering the obtained Chromium (III) Phosphate suspension as a matrix for the preparation of radiopharmaceuticals to be used in radiosinoviorthesis aimed at various joints, depending on the physical and nuclear characteristics of the radionuclides

Fatores de correção volumétrica na medição de atividade de 99mTc e 123I em calibradores de radionuclídeos / Volume corrections factors in the measurement of 99mTc and 123I activities in radionuclide calibrators

OBJETIVO: Determinar os fatores de correção para a variação volumétrica dos radiofármacos contidos em recipientes de diferentes geometrias. Comparar a influência desses fatores na determinação da atividade de 99mTc e 123I utilizando dois tipos de calibradores: um com câmara de ionização e outro com detector Geiger-Müller (G-M). Avaliar o desempenho de calibradores de alguns serviços de medicina nuclear em medição de atividade de 99mTc e 123I. MATERIAIS E MÉTODOS: Foram utilizados oito calibradores, frascos de vidro 10R, seringas de plástico de 3 e 5 mL e soluções de 99mTc e 123I. Os fatores de correção foram determinados a partir das medições práticas da variação da leitura do calibrador com a variação do volume da solução no recipiente. O desempenho foi avaliado em relação ao critério de aceitação de ±10% de exatidão exigida pela norma brasileira. RESULTADOS: A variação da resposta do calibrador com a variação do volume do frasco foi bem maior no calibrador que utiliza G-M. Ela também foi maior para 123I do que para 99mTc. CONCLUSÃO: Os resultados confirmam que a resposta dos calibradores depende do volume contido nos recipientes. Essa dependência é mais crítica para os calibradores equipados com detector G-M e para 123I quando comparado com 99mTc.

OBJECTIVE: To determine correction factors for the variation in volume of radiopharmaceuticals in containers of different geometries, comparing the influence of such factors on the determination of 99mTc and 123I activity with two types of calibrators - one with ionization chamber and another with Geiger-Müller (G-M) detector -; and to evaluate calibrators performance in the measurement of 99mTc and 123I activities. MATERIALS AND METHODS: Eight calibrators, 10R glass vials, 3 and 5 mL plastic syringes and 99mTc and 123I solutions were utilized. The correction factors were determined with basis on practical measurements of the variation in the calibrators' response according to the volume of radionuclide solution in the glass vials. The performance was evaluated according to the acceptance criterion of ±10% accuracy required by the Brazilian standard. RESULTS: The variation of the calibrators' response according to the variation in radionuclide volume was reasonably greater in the calibrator with G-M detector. It was also greater for 123I than for 99mTc. CONCLUSION: The results confirm that the calibrators' response depends on the radionuclide volume contained in the vials. Such dependence is more critical for the calibrators equipped with G-M detector and for 123I as compared with 99mTc.

Polymeric micelles and molecular modeling applied to the development of radiopharmaceuticals

Micelles composed of amphiphilic copolymers linked to a radioactive element are used in nuclear medicine predominantly as a diagnostic application. A relevant advantage of polymeric micelles in aqueous solution is their resulting particle size, which can vary from 10 to 100 nm in diameter. In this review, polymeric micelles labeled with radioisotopes including technetium (99mTc) and indium (111In), and their clinical applications for several diagnostic techniques, such as single photon emission computed tomography (SPECT), gamma-scintigraphy, and nuclear magnetic resonance (NMR), were discussed. Also, micelle use primarily for the diagnosis of lymphatic ducts and sentinel lymph nodes received special attention. Notably, the employment of these diagnostic techniques can be considered a significant tool for functionally exploring body systems as well as investigating molecular pathways involved in the disease process. The use of molecular modeling methodologies and computer-aided drug design strategies can also yield valuable information for the rational design and development of novel radiopharmaceuticals.

Micelas poliméricas compostas de copolímeros ligadas a um elemento radioativo são utilizadas em Medicina Nuclear com aplicação predominantemente diagnóstica. A vantagem relevante da utilização de micelas poliméricas em solução aquosa é o tamanho de suas partículas, as quais podem variar de 10 a 100 nm de diâmetro. Neste trabalho de revisão são apresentadas micelas poliméricas marcadas com radioisotopos, como tecnécio-99m (99mTc) e índio-111 (111In), assim como suas aplicações clínicas em técnicas de diagnóstico como Tomografia por emissão de Fóton Único (Single photon Emission Computed Tomography - SPECT), cintilografia, e Ressonância Magnética Nuclear (RMN). Neste contexto, sua aplicação em diagnóstico de sistema linfático e linfonodo sentinela recebe atenção especial. O emprego de técnicas de diagnóstico pode ser considerado uma ferramenta importante para a exploração de sistemas no organismo humano assim como para a investigação de caminhos moleculares envolvidos nos processos de diversas doenças. O uso de metodologias de modelagem molecular e estratégias de desenvolvimento de fármacos assistidas computacionalmente também pode fornecer informações valiosas para o planejamento e o desenvolvimento racional de novos radiofármacos.

Factor analysis for the adoption of nuclear technology in diagnosis and treatment of chronic diseases / Análise de fatores para adoção da tecnologia nuclear no diagnóstico e tratamento de doenças crônicas

Objective: To identify and evaluate latent variables (variables that are not directly observed) for adopting and using nuclear technologies in diagnosis and treatment of chronic diseases. The measurement and management of these latent factors are important for healthcare due to complexities of the sector. Methods: An exploratory factor analysis study was conducted among 52 physicians practicing in the areas of Cardiology, Neurology and Oncology in the State of Sao Paulo who agreed to participate in the study between 2009 and 2010. Data were collected using an attitude measurement questionnaire, and analyzed according to the principal component method with Varimax rotation. Results: The component matrix after factor rotation showed three elucidative groups arranged according to demand for nuclear technology: clinical factors, structural factors, and technological factors. Clinical factors included questionnaire answers referring to medical history, previous interventions, complexity and chronicity of the disease. Structural factors included patient age, physician's practice area, and payment ability. Technological factors included prospective growth in the use of nuclear technology and availability of services. Conclusions: The clinical factors group dimension identified in the study included patient history, prior interventions, and complexity and chronicity of the disease. This dimension is the main motivator for adopting nuclear technology in diagnosis and treatment of chronic diseases.

Objetivo: Identificar e avaliar as variáveis latentes (que não podem ser observadas diretamente) no processo de adoção e uso de tecnologias nucleares no diagnóstico e tratamento de doenças crônicas. A mensuração e a gestão dos fatores latentes são importantes dentro da área da Saúde devido às complexidades inerentes do setor. Métodos: Foi realizado um estudo do tipo fatorial exploratório com 52 médicos das especialidades de Cardiologia, Neurologia e Oncologia no Estado de São Paulo que participaram do estudo entre 2009 e 2010. Os dados foram coletados por meio de questionário de mensuração de atitudes e analisados pelo método dos componentes principais, com rotacionamento do tipo Varimax. Resultados: A matriz de componentes após a rotação dos fatores apresentou três agrupamentos explicativos ordenados para a demanda de uso das tecnologias nucleares: fatores clínicos, fatores estruturais e fatores tecnológicos. O fator clínico é formado por respostas referentes a histórico clínico, intervenção anterior, complexidade e cronicidade. O fator estrutural é composto por idade do paciente, área de atuação do médico e capacidade de pagamento; o fator tecnológico diz respeito às perspectivas de aumento do uso da tecnologia nuclear - quantidade de serviços. Conclusões: A dimensão de fatores clínicos é composta por histórico clínico, intervenção anterior, complexidade e cronicidade da doença. Essa dimensão é o principal motivador para adoção da tecnologia nuclear no diagnóstico e tratamento das doenças crônicas.