Research on the formulation and revision of radiological parameters in the "Standards for Drinking Water Quality（GB5749-2022）" in China / 中华预防医学杂志

The radioactive safety of drinking water has attracted increasing public concern. The newly issued Standards for Drinking Water Quality (GB5749-2022) in China has revised the radiological parameters. This article provides an overview of the main sources, levels of radionuclides in drinking water, and summarized the individual doses criterion and adverse health effects associated with exposure of the public to radionuclides from drinking-water. It analyzes and discusses the relevant revision content of radiological parameters, including the guidance values for screening gross α and gross β, subtracting the contribution of potassium-40 from gross β activity when the gross β activity concentration exceeds the screening level, and the basis for establishing the limit values of reference indices uranium and radium-226. Specific implementation and evaluation suggestions are also proposed.

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.

Recent progress of positron radionuclide labeled small molecule inhibitors of prostate specific membrane antigen for PET/CT imaging of prostate cancer / 生物医学工程学杂志

Prostate cancer is the most common tumor of the urinary system, and its mortality rate is second only to lung cancer. With the specific and high expression on the surface of prostate cancer cells, prostate-specific membrane antigen (PSMA) has been an ideal theranostic target of prostate cancer with great clinical significance and research value. Positron emission tomography/computed tomography (PET/CT), a new modality of molecular imaging combining functional metabolic information and anatomical structure, provides high diagnostic performance for cancer detection. This paper mainly reviewed recent progress of PSMA inhibitors labeled by positron-emitting radionuclides for early diagnosis, preoperative staging, response assessment, restaging and metastasis detection of prostate cancer.

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.

Perspectives for Concepts of Individualized Radionuclide Therapy, Molecular Radiotherapy, and Theranostic Approaches / 대한핵의학회잡지

Radionuclide therapy (RNT) stands on the delivery of radiation to tumors or non-tumor target organs using radiopharmaceuticals that are designed to have specific affinity to targets. RNT is recently called molecular radiotherapy (MRT) by some advocators in order to emphasize its characteristics as radiotherapy and the relevance of dosimetry-guided optimization of treatment. Moreover, RNT requires relevant radiation protection standards because it employs unsealed radionuclides and gives therapeutic radiation doses in humans. On the basis of these radiation protection standards, the development and use of radiopharmaceuticals for combined application through diagnostics and therapeutics lead to theranostic approaches that will enhance the efficacy and safety of treatment by implementing dosimetry-based individualization.

Quantitative Imaging of Alpha-Emitting Therapeutic Radiopharmaceuticals / 대한핵의학회잡지

Targeted alpha therapy (TAT) is an active area of drug development as a highly specific and highly potent therapeutic modality that can be applied to many types of late-stage cancers. In order to properly evaluate its safety and efficacy, understanding biokinetics of alpha-emitting radiopharmaceuticals is essential. Quantitative imaging of alpha-emitting radiopharmaceuticals is often possible via imaging of gammas and positrons produced during complex decay chains of these radionuclides. Analysis of the complex decay chains for alpha-emitting radionuclides (Tb-149, At-211, Bi-212 (decayed from Pb-212), Bi-213, Ra-223, Ac- 225, and Th-227) with relevance to imageable signals is attempted in this mini-review article. Gamma camera imaging, single-photon emission computed tomography, positron emission tomography, bremsstrahlung radiation imaging, Cerenkov luminescence imaging, and Compton cameras are briefly discussed as modalities for imaging alpha-emitting radiopharmaceuticals.

Efforts in the Formation and Development of Nuclear Medicine in Vietnam / 대한핵의학회잡지

The foundations of nuclear medicine in Vietnam were established from 1970. Until now, after 48 years of development, in Vietnam, we have some basic equipment including 31 SPECT, 4 SPECT/CT machines, 11 PET/CT scanners, five cyclotrons, and one nuclear reactor.Many nuclearmedicine techniques in diagnosis and treatment have been routinely performed at provincial and central level health facilities such as tumor scintigraphy, thyroid scintigraphy, bone scintigraphy, kidney scintigraphy, cardiac scintigraphy, and radio-isotope therapy with I-131 and P-32. Selective internal radiation therapy with Y-90 microsphere and I-125 radioactive seed implantation has been also successfully applied in some big hospitals. However, there are still many difficulties for Vietnam as the lack of new widely used radioisotopes such as Ga-67, Cu-64, Samarium-153, and Lutetium-177 and the lack of nuclear medicine specialists. In the future, we are putting our efforts on the applications of new isotopes in diagnosis and treatment of cancers (theranostic) like Ga-68-DOTATATE, Lutetium-177-DOTATATE, Ga-68-PSMA, and Lutetium-177-PSMA, equipping modern nuclear medicine diagnostic tools, strengthening the human resources training in nuclear medicine. At the same time, we are trying our best to strengthen the cooperation with international nuclear medicine societies in over the world.

Successful Treatment in a Newborn Infant with Chylous Ascites and Chylous Hydrocele

Chyle only occurs in the peritoneal cavity or around the pericardium through damage to the lymph nodes or improper drainage of the lymph and is characterized by a colostrum-like color and being rich in triglyceride. We encountered a case of a newborn infant with abdominal distention and further diagnosed chylous ascites and hydrocele by inspecting and analyzing the fluid obtained from the abdominal cavity and scrotum. Additionally, a lymphoscintigraphy was performed, which showed a decrease in the uptake of radioactive isotopes in the left iliac nodes and a delayed appearance. Here, we report a case of chyle diagnosed through puncture analysis and its subsequent successful treatment.

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)

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.

Near-Infrared Fluorescence Lymph Node Navigation Using Indocyanine Green for Gastric Cancer Surgery

Near-infrared (NIR) fluorescence imaging is a promising method for image-guided surgery, providing robust functional images with relatively good cost-effectiveness. A cyanine vital dye indocyanine green (ICG) is a safe NIR fluorophore emitting 800~840 nm of light and has been used in numerous surgical procedures. The technique has been applied to lymph node navigation of gastric cancer surgery with an expectation of better visualization of lymphatic structures without any risk of radio-hazard compared with a “dual method” using both vital dyes and radioisotopes. Given the characteristics of ICG, such as fast distribution and quenching effect, diluted concentrations, such as 0.05~0.1 mg/ml, are thought to be optimal for sentinel node navigation. Injection into the subserosal layer is feasible; however, endoscopic submucosal injection has advantages of improved accuracy of the injection site and feasibility of injection one day prior to surgery; these advantages are preferred by some investigators due to a smaller number of sentinel nodes compared with injection in the operation theatre. The technology requires evaluation of the sensitivity and specificity, as well as the non-inferiority, compared with the dual method in a large cohort for justification as a safe node navigation method.

Influence of Ectomycorrhizal Colonization on Cesium Uptake by Pinus densiflora Seedlings

Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.

Peptide Receptor Radionuclide Therapy and the Treatment of Gastroentero-pancreatic Neuroendocrine Tumors: Current Findings and Future Perspectives / 대한핵의학회잡지

PURPOSE AND METHODS: Patients with inoperable andmetastasized neuroendocrine tumors (NETs), particularly those with grades 1 and 2, usually receive treatment with somatostatin analogues (SSAs). Peptide receptor radionuclide therapy (PRRT) has gained momentum over the past two decades in patients who progress on SSAs. 177Lu-DOTATATE is currently the most widely used radiopeptide for PRRT. We reviewed the recent evidence on PRRT and the treatment of gastroentero-pancreatic neuroendocrine tumors (GEP-NETs).RESULTS: ¹⁷⁷Lu-DOTATATE can be used as neoadjuvant treatment in patients with inoperable GEP-NETs, who might be candidate for surgery after treatment and as adjuvant therapy after surgical intervention. Combination treatments of PRRT with chemotherapy or targeted agents as well as combinations of radionuclides in patients with NETs have been explored over the last few years. The majority of patients with NETs experience partial response or have disease stabilization, a small percentage has complete response, while some 30% of patients, however, will have disease progression. The safety and efficacy of retreatment with extra cycles of PRRT as salvage therapy have been evaluated in small retrospective series.CONCLUSION: Overall, there is evidence that disease control and quality of life improve significantly after 117Lu PRRT therapy. Clinical trials on this therapy are scarce, and there is a need for further studies to establish proper management guidelines.

Radioimmunotherapy in Head and Neck Cancer / 대한이비인후과학회지

Radioimmunotherapy (RIT) is a therapy that takes advantage of the “cross-fire” effect of emitted radiation by radionuclides conjugated to tumor-directed monoclonal antibodies (mAb) (including those fragments) or peptides. While RIT has been successfully employed for the treatment of lymphoma, mostly with radiolabeled antibodies against CD20 [⁹⁰yttrium (⁹⁰Y)-ibritumomab tiuxetan; Zevalin® and (131)iodine ((131)I)-tositumomab; Bexxar®], its use in solid tumors is more challenging, so far. Immuno-PET, a tool for tracking and quantification of mAbs with PET in vivo, is an exciting novel option to improve diagnostic imaging and guide mAbbased therapy. RIT in solid tumors including head and neck cancer may be an alternative treatment with advances in various biological, chemical, and treatment procedures, and it may help to reduce unnecessary exposure and enhance the therapeutic efficacy. Also, immuno-PET based on RIT might play an important role in cancer staging, in patients or targets selection of targeted therapeutics and in monitoring the response of targeted therapeutics as precision medicine. In this review, fundamentals of RIT/immune-PET and current knowledge of the preclinical/clinical trials in RIT for solid tumor including head and neck cancer are reviewed.

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

Radionuclide concentrations and excess lifetime cancer risk due to gamma radioactivity in tailing enriched soil around Maiganga coal mine, Northeast Nigeria

Background: Human activities such as mining enhance the radioactivity levels above normal background which can lead to an incremental increase in the radiation risk to the population

Materials and Methods: 20 tailing enriched soil samples collected around Maiganga coal mine, Gombe, Northeast Nigeria were assessed for their[226]Ra,[232]Th and [40]K contents using HPGe gamma-ray detector

Results: The mean activity values of 11.9013.0, 17.72+/-3.6 and 70.44+/-20.4 Bq kg[-1] were obtained for [226]Ra, [232]Th and [40]K respectively. These values were below the world average values documented by UNSCEAR. The ratio of [232]Th:[226]Ra obtained was 1.5, which showed that [232]Th activity was higher than the activity of [226]Ra while [40]K recorded the highest activity concentration in the studied samples. Statistical analysis identified strong positive relationships among all radiological parameters and confirmed that [225]Ra,[232]Th and [40]K were the major contributors to radiation dose. Radium equivalent activity [Ra[eg]], absorbed gamma dose rate [D[r]], annual effective dose [AEDE], activity utilization index [AUI], external and internal hazard indices [H[ex]] and H[in], gamma representative index [l[vr]], annual gonadal dose [AGDE] and excess lifetime cancer risk [ELCR] were calculated to quantify the radiation risk to the public from exposure to[226]Ra, [232]Th and [40]K in the studied samples. The mean values of these hazard parameters were within the acceptable limits provided for human safety and environmental protection

Concfusfon: The use of the raffing enrfcnecf soff sampfes of Maiganga coaf mine for any purpose whatsoever does not therefore pose any immediate radiological risk to the coaf workers or the general pubfic

Radium-223 for the treatment of bone metastasis of prostate cancer / 中华男科学杂志

Over 80% of the patients with prostate cancer (PCa) develop bone metastasis, which seriously affects the patients' quality of life and remains a major cause of morbidity. Radium-223 (Ra-223), a newly approved agent targeting bone metastasis of PCa, can improve the quality of life and prolong the overall survival of the PCa patients with bone metastasis. This article presents an overview of the clinical trials recently published on the management of bone metastasis of PCa with Ra-223.