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)

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...

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.

Estudio biocinético y dosimétrico de un kit de producción local de 177Lu-EDTMP para su uso como agente paliativo del dolor / Biokinetic and dosimetric study of 177Lu-EDTMP in the palliative treatment of skeletal metastasis

Los radiofármacos con afinidad por el tejido óseo como el ácido etilen-diamino-tetrametilen-fosfónico (EDTMP) marcado con radioisótopos emisores beta- han demostrado su eficacia en el tratamiento paliativo de las metástasis óseas. Se realizó un estudio biocinético y dosimétrico del 177Lu-EDTMP en ratones NIH. Los resultados obtenidos fueron extrapolados a humanos. Se estimó la dosis absorbida en órganos para dos modelos: un hombre adulto y una mujer adulta. El 177Lu-EDTMP posee una selectiva captación en hueso, una rápida eliminación en sangre e insignificante captación en tejidos no óseos. La dosis en hueso estimada para el hombre se encuentra entre 14,7-15,3 cGy/mCi y entre 19,6-20,4 cGy/mCi para la mujer. La toxicidad en médula ósea representa el factor limitante de este tipo de terapia, y para evitar superar la dosis máxima que ésta puede tolerar (200 cGy), se encontró que la actividad máxima segura de 177Lu-EDTMP que puede ser inyectada al hombre (73,9Kg), corresponde a un valor de 1,01 mCi/kg y a un valor de 1,25 mCi/Kg para la mujer (56,9Kg).

Bone-seeking radiopharmaceuticals like the ethylenediaminetetramethylene phosphonic acid (EDTMP) labeled with beta--emitting radioisotopes have demonstrated their efficacy in the palliative treatment of skeletal metastasis. A biokinetic and dosimetric study of 177Lu-EDTMP in NIH mice was performed. The results obtained were extrapolated to human. We estimate the absorbed doses in organs for two models: an adult male and an adult female. 177Lu-EDTMP has a selective uptake in bone, a rapid elimination from blood and negligible uptake in non-skeletal tissues. The estimated dose in bone is between 14.7-15.3 cGy/mCi for men and between 19.6-20.4 cGy/mCi for women. Bone marrow toxicity represents the limiting factor in this kind of therapy, and to avoid exceed the maximum dose it can tolerate (200 cGy), it was found that the maximum safe activity of 177Lu-EDTMP to be injected to male (73.9 kg), corresponds to a value of 1.01 mCi/kg and a value of 1.25 mCi/kg for female (56.9 kg).

Effectiveness of radiation synovectomy with samarium-153 particulate hydroxyapatite in rheumatoid arthritis patients with knee synovitis: a controlled randomized double-blind trial

OBJECTIVES: The aim of the present study was to investigate the effectiveness of Samarium153-particulate hydroxyapatite radiation synovectomy in rheumatoid arthritis patients with chronic knee synovitis. METHODS: Fifty-eight rheumatoid arthritis patients (60 knees) with chronic knee synovitis participated in a controlled double-blinded trial. Patients were randomized to receive either an intra-articular injection with 40 mg triamcinolone hexacetonide alone (TH group) or 40 mg triamcinolone hexacetonide combined with 15 mCi Samarium153-particulate hydroxyapatite (Sm/TH group). Blinded examination at baseline (T0) and at 1 (T1), 4 (T4), 12 (T12), 32 (T32), and 48 (T48) weeks post-intervention were performed on all patients and included a visual analog scale for joint pain and swelling as well as data on morning stiffness, flexion, extension, knee circumference, Likert scale of improvement, percentage of improvement, SF-36 generic quality of life questionnaire, Stanford Health Assessment Questionnaire (HAQ), Lequesne index, use of non-steroidal anti-inflammatory drugs or oral corticosteroids, events and adverse effects, calls to the physician, and hospital visits. RESULTS: The sample was homogeneous at baseline, and there were no withdrawals. Improvement was observed in both groups in relation to T0, but no statistically significant differences between groups were observed regarding all variables at the time points studied. The Sm/TH group exhibited more adverse effects at T1 (p<0.05), but these were mild and transitory. No severe adverse effects were reported during follow-up. CONCLUSION: Intra-articular injection of Samarium153-particulate hydroxyapatite (15 mCi) with 40 mg of triamcinolone hexacetonide is not superior to triamcinolone hexacetonide alone for the treatment of knee synovitis in patients with rheumatoid arthritis at 1 y of follow-up.

The role of electron-emitting radiopharmaceuticals in the palliative treatment of metastatic bone pain and for radiosynovectomy: applications of conversion electron emitter Tin-117m

A variety of radionuclides continue to be investigated and/or clinically used for different therapeutic applications in nuclear medicine. The choice of a particular radionuclide with regard to appropriate emissions, linear energy transfer (LET), and physical half-life, etc., is dictated to a large extent by the character of the disease (e.g., solid tumor or metastatic disease), and by the carrier to selectively transport the radionuclide to the desired site. An impressive body of information has appeared in the recent literature that addresses many of these considerations. This article summarizes and discusses the role of high-LET electron emitters and their advantage in the treatment of cancer or for other disorders in specific situations. Areas such as bone pain palliation, bone malignancy therapy, and radiation synovectomy are covered in greater detail. Projections are made as to the future directions and progress in these areas. A discussion of the various issues related to the selection criteria that are useful for choosing the appropriate radionuclide for a particular application is included. Use of high-LET electron emitters is discussed in greater detail, with particular emphasis on the use of conversion electron emitter tin-117m for various therapeutic applications.

Uma variedade de radionuclídeos continua a ser investigada e/ou clinicamente utilizada para diferentes aplicações terapêuticas em medicina nuclear. A escolha de um radionuclídeo, considerando-se sua emissão apropriada, transferência linear de energia (LET) e meia-vida física é determinada na maior parte pelo caráter da doença (p.ex., tumor sólido ou doença metastática), e pelo carreador que transporta o radionuclídeo seletivamente para o sítio desejado. Um notável conjunto de informações voltadas para essas considerações tem aparecido na literatura recente. Esse trabalho resume e discute o papel de emissores de elétrons de alta-LET e sua vantagem no tratamento do câncer ou para outras doenças em situações específicas. Abordagens relacionadas com o alívio da dor óssea, a terapia da doença óssea e a sinovectomia por radiação são apresentadas detalhadamente. Projeções para o futuro e os progressos nessas áreas são indicadas. Uma profunda discussão relacionada aos critérios de seleção que são úteis para escolher o radionuclídeo apropriado para que uma aplicação particular seja incluída. O uso de emissores de elétrons de alta-LET é discutido em grande detalhe, com particular ênfase no uso do estanho-117m, um emissor de elétron de conversão, para várias aplicações terapêuticas.

Role of chelates in treatment of cancer.

Chelates are used in cancer as cytotoxic agent, as radioactive agent in imaging studies and in radioimmunotherapy. Various chelates based on ruthenium, copper, zinc organocobalt, gold, platinum, palladium, cobalt, nickel and iron are reported as cytotoxic agent. Monoclonal antibodies labeled with radioactive metals such as yttrium-90, indium-111 and iodine-131 are used in radioimmunotherapy. This review is an attempt to compile the use of chelates as cytotoxic drugs and in radioimmunotherapy.

Effects of Intraluminal Irradiation with Holmium-166 for TIPS Stenosis: Experimental Study in a Swine Model

OBJECTIVE: We wanted to evaluate the effectiveness of intraluminal irradiation with Holmium-166 (166Ho) for reducing the pseudointimal hyperplasia (PIH) in the transjugular intrahepatic portosystemic shunt (TIPS) tract in a swine model. MATERIALS AND METHODS: TIPS was performed in 12 domestic pigs, after the creation of portal hypertension by intraportal injection of a mixture of N-butyl-2-cyanoacrylate (NBCA) and lipiodol. Five pigs first underwent intraluminal irradiation (30 Gy) in the parenchymal tract with using a 166Ho solution-filled balloon catheter, and this was followed by the placement of a nitinol stent in the TIPS tract. For the seven control pigs, the balloon was filled with saline and contrast media mixture. Two weeks later, follow-up portography and histological analysis were performed. RESULTS: TIPS was successfully performed in all twelve pigs with achieving artificially induced portal hypertension. Portography performed two weeks after TIPS showed the patent tracts in the TIPS tracts that were irradiated with 166Ho (5/5, 100%), whereas either completely (5/6, 83.3%) or partially (1/6, 16.7%) occluded TIPS were seen in the seven pigs of the nonirradiated control group, except in one pig that experienced periprocedural death due to bleeding. Histological analysis showed a statistically significant difference for the maximal PIH (irradiated: 32.8%, nonirradiated: 76.0%, p < 0.001) between the two groups. CONCLUSION: Intraluminal irradiation with 30 Gy of 166Ho for TIPS significantly improved the TIPS patency in a swine model of portal hypertension during a 2-week period of follow-up.

Juvenile hyperthyroidism: an experience.

OBJECTIVE: To analyze the clinical profile of juvenile hyperthyroidism at presentation, their treatment outcome; predictors of remission and relapse. METHODS: Retrospective analysis of medical records of 56 patients with juvenile hyperthyroidism seen over a period of 16 years. A cohort of 38 females and 18 males with mean (+/-SD) age of 14.9 +/- 3.4 years (range 3 to 18 years) was analyzed. RESULTS: Majority of patients was in the age group of 12-16 years. Common symptoms observed at presentation were weight loss (82.1%), excessive sweating (78.6%), heat intolerance (76.8%), increased appetite (73.2%) and diarrhea in 48.2%. In addition, accelerated linear growth was observed in 7.1% of patients. Goiter was present in 98.2% of children; 94.5% of which was diffuse and 4.8% was multinodular. The mean ((+/-SD) T3 was 4.8 +/- 3.4 ng/mL (N, 0.6-1.6), T4 was 218 +/- 98 ng/mL (N, 60-155) and TSH was 0.44 +/- 0.36 (N, 0.5-5.5 microIU/mL). TMA positivity seen in 36.9% of patients. All patients were treated with carbimazole; subsequently 4 patients required thyroidectomy and one required radioactive iodine ablation. Mean (+/-SD) duration of follow-up in our patients was 4.9 +/- 3 years, ranging between 1.6 to 16 years and mean (+/-SD) duration of treatment was 34.4 +/- 22.6 months (range 12 to 120 months). Mean (+/-SD) duration to achieve euthyroidism was 5.2 +/- 4.7 months, ranging between 1-33 months. On intention to treat analysis, remission with carbimazole was achieved in 47.6%, remaining patients failed to achieve remission with drug treatment. CONCLUSION: Graves disease is the commonest cause of juvenile hyperthyroidism. Carbimazole is safe, effective, cheap, and easily available form of therapy. It is occasionally associated with serious side effects but requires prolonged follow up.

Tratamiento de lesiones hepáticas tumorales con RENIO188- LIPIODOL. Experiencia en Colombia / Treatment of liver cancer injuries with RENIO188- LIPIODOL. Experience in Colombia

Objetivo: Evaluar pacientes con lesiones tumorales hepáticas, no quirúrgicas, a quienes se les administro Renio 188 -Lipiodol vía transarterial, como alternativa terapéutica.Método: Once pacientes con cáncer de hígado no operable se trataron con dosis entre 170 y 4181 MBq de Renio 188 Lipiodol a través de la arteria hepática. Los pacientes fueron evaluados clínicamente, con test hematológicos, de función hepática y TAC hepático periódicamente.Resultados: El tratamiento con Renio 188 Lipiodol fue bien tolerado . Tres pacientes desarrollaron fiebre leve y un paciente Neumonitis Intersticial que resolvió completamente. En el TAC de control siete pacientes evidenciaron reducción significativa del tamaño de la lesión , 1 sin cambios, 1 progresión y 2 no se han evaluado.Conclusiones: Renio 188 Lipiodol es un tratamiento seguro, la técnica de preparación fácilmente reproducible y se constituye en una alternativa terapéutica para este tipo de pacientes.

Revisión de modalidades no quirúrgicas del tratamiento del carcinoma hepatocelular / Revision of nonsurgical modalities of the treatment of the hepatocellular carcinoma

El carcinoma hepatocelular es una de las neoplasias más comunes en el mundo, con una sobrevida pobre que varía de un rango 2.5 ± 1.9 meses dependiendo del estadio de la enfermedad al momento del diagnostico y del tipo de tratamiento realizado. La resección quirúrgica completa es el único tratamiento que ha demostrado obtener el período mas prolongado de sobrevida a 5 años, desafortunadamente, muchos de los pacientes con hepatocarcinoma no son candidatos a resección quirúrgica por lo que ha surgido gran interés en las nuevas técnicas ablativas no resecantes ya que son mínimamente invasivas y han alterado el abordaje y la forma de tratar a muchos de los pacientes. El objetivo de este artículo fue revisar las nuevas técnicas no quirúrgicas, con énfasis en las Terapias con radionuclidos.

Protocolos de estudio de perfusión miocárdica con radioisotopos en evaluación de cardiopatía coronaria / Studies of myocardial perfusion using radioisotopes in the coronary heart disease

Se revisan los principales protocolos actuales de perfusión miocárdica con técnica isotópica, sus indicaciones, requerimientos y nuevas aplicaciones. Se da especial énfasis a la técnica de SPECT gatillado que agrega parámetros de función a las imágenes tomográficas con mayor valor diagnóstico y pronóstico y también a la introducción de positrones mediante fluordeoxiglucosa en la detección de viabilidad miocárdica.

Angioplastia transluminal coronaria asociada a radiación con 188Re. Primer caso de radiación intracoronaria en Uruguay / Transluminal coronary angioplasty associated with 188Re radiation. First case of intracoronary radiation in Uruguay

La restenosis luego de una angioplastia transluminal coronaria exitosa es uno de los problemas más preocupantes en el área de la cardiología intervencionista. Uno de los métodos que se han desarrollado para la prevención y el tratamiento de esta restenosis es la radiación intracoronaria. Se reporta el primer caso tratado en Uruguay con radiación intracoronaria mediante la aplicación de un balón con 188Re. Entre las ventajas que tendría este método sobre otros de radiación intracoronaria se destacan su bajo costo y la facilidad de su aplicación, sin requerir dispositivos costosos ni infraestructura sofisticada de radioprotección. La experiencia acumulada con esta nueva técnica muestra que es un procedimiento factible y seguro. Debe aguardarse más información acerca de la eficacia del mismo en la evolución alejada.

Nuclear medicine in the treatment of endocrine and neuroendocrine tumors

Radionuclide therapy plays an important role in the treatment of endocrine and neuroendocrine tumors. Therapy with 131I is used in patients with papillary and follicular thyroid carcinoma for ablation of thyroid remnants and for treatment of distant metastases. In neck recurrence, 131I may be used as monotherapy or in combination with surgery. Both radioimmunotherapy and 90Y-DOTATOC are being applied in non-131I-avid thyroid malignancies such as medullary thyroid carcinoma. 131I-MIBG is currently used in various treatment schedules for recurrences and metastases of neuroblastoma, pheochromocytoma, paraganglioma and carcinoid. In neuroblastoma 131I-MIBG can be given upfront to reduce large and bulky tumors for subsequent surgery, chemotherapy and autologus bone marrow infusion. In carcinoid and other neuroendocrine tumors therapy with radiolabelled somatostatin analogues appears to be a promising modality. Radiopharmaceutical quality requirements, patient preparation, radiation protection and hospital isolation facilities are important supportive factors to enable adequate radionuclide therapy

Uso de radioisótopos en metástasis óseas dolorosas: samario 153 EDTMP / Use of radioisotopes in painful bone metastasis: samarium 153 EDTMP

Los pacientes con dolor debido a metástasis óseas deben ser tratados por un equipo multidisciplinario. Los mecanismos de producción del dolor son poco conocidos y su fisiopatología es compleja, su evolución es progresiva y su manejo difícil. Entre las alternativas terapéuticas del dolor está el uso de isótopos radioactivos, que irradian al órgano blanco mediante emisión de partículas beta. Entre estos isótopos se encuentra el Samario153-EDTMP que está diponible en nuestro país y que tiene una bio distribución favorable y características fisioquímicas y de toxicidad aceptables para ser utilizado en metástasis principalmente osteoblásticas con alivio progresivo del dolor desde las primeras 48 horas y con una duración entre 4 a 35 semanas

Tratamiento paliativo del dolor óseo con samario-153-EDTMP en pacientes con cáncer / Palliative treatmen for bone pain with samarium-153-EDTMP in patients with cancer

El dolor óseo es una causa común de consulta médica y de predominio en la práctica oncológica. Los síntomas asociados con metástasis son comunes y contribuyen a una reducción importante en la calidad de vida de la población afectada. Recientemente se cuenta con un recurso terapéutico que consiste en la administración sistemática de radiofármacos que se concentran selectivamente en hueso. En un año atendimos nueve pacientes, ocho con cáncer de próstata y uno con cáncer de mama, con rango de edad de 46 a 80 años que cumplieron con los requisitos para recibir el tratamiento, consistente en la aplicación endovenosa de 0.75 milicuries de samario-153 por kilogramo de peso. A las 24 horas se realizó rastreo óseo para corroborar la concentración del radiofármaco en las lesiones blásticas. También se solicitó registro diario del dolor utilizando una escala de cero a 10, así como biometría hemática completa y determinación de antígeno prostático específico a las seis semanas. Los nueve pacientes tratados presentaron disminución del dolor, la cual se cuantificó en 80 por ciento con una duración media de tres meses y sin terapia con analgésicos. Consideramos que el samario-153 es una excelente alternativa para el tratamiento paliativo del dolor óseo, especialmente en aquellos pacientes en quienes han fallado otros esquemas terapéuticos

Producción de juegos de reactivos fríos para radiofarmacos de tecnecio-99m en Venezuela / Production of the cold kits by radio pharmaceutical with teenecium-99m in Venezuela

El avance de la Medicina Nuclear en los últimos años otorga el lugar preferencial, en esta disiplina médica, a los Radiofármacos para diagnóstico que incorporan Tecnecio 99 metaestable como radionucleido ligado a diferentes moléculas orgánicas, de distribución biológica definida, cuya ubicación en un organo determinado es específica. Los Reactivos Fríos están constituidos por esta sustancia orgánica y otros compuestos, que se preparan generalmente liofilizados, para posteriormente ser reconstituidos con una solución estéril del Tecnecio-99m. En Venezuela se inició el desarrollo de la Radiofarmacia como práctica profesional farmacéutica, con el objeto de producir los Radiofármacos en el país. Se plantea comenzar con los reactivos fríos para radiofármacos de diagnóstico, los cuales deberán cumplir con los siguientes atributos: certificado de calidad, disponibilidad de asesoría, buen servicio de suministro y el menor costo. Con la finalidad de proveer a los Servicios de Medicina Nuclear del país, es necesario establecer contacto con los profesionales de dichos servicios y conocer las necesidades reales de estos productos. En el presente trabajo se muestran los resultados de una primera etapa cumplida para la cual, en primer lugar, se ha realizado una Investigación de Mercados en los Servicios de Medicina Nuclear del área metropolitana de Caracas, tanto públicos como privados, a través de una encuesta realizada a los profesionales Médicos y Técnicos Nucleares, obteniéndose información acerca del tipo y número de estudio para diagnóstico, que se realizan anualmente en dichos servicios. En segundo lugar, una vez conocido cuales son los reactivos fríos de uso más frecuente, se prepararon en pequeña escala lotes piloto de MDP, DTPA, DMSA y Sulfuro Coloidal, mediante transferencia de tecnologías, tanto para produción como para control de calidad físico-químico, obteniéndose resultados satisfactorios en todos los lotes preparados y analizados. Los resultados obtenidos constituyen un soporte para poder llevar a cabo con confianza, en la próxima etapa, la producción de en gran escala de los reactivos fríos ensayados, y además desarrollar la producción de los demás que se requieran en nuestro país

153 SmEDTMP de producción nacional en el tratamiento paliativo del dolor óseo metastásico / 153 SmEDTMP of national production in the palliative treatment of metastasic bone pain

153 SmEDTMP was obtained from enriched 153Sm irradiated at the 5 MW Chilean Research reactor and labelled at a molar ratio of 15:1 pH 7.5. Biodistribution, autoradiography, radiochemical purity tests were done for evaluation. 40 patients were treated with 37-55 MBq/kg weight. Bone scans using 99mTcHMDP were obtained prior and after treatment. Bone marrow depression was observed in 37 percent of them and normal liver function in all of them. In 45 percent the pain dissapear completely, in 22,5 percent significantly decreased and partially in 30 percent. In 17 patients more than one dosis was injected. Our preliminary results indicate that 153 SmEDTMP is a promising radiotherapeutic agent for palliative treatment of metastasic bone cancer pain and encourage its use specially because it can be produced in countries with low economic resources, thus a large number of patients can get the benefits of this new procedure