Brachytherapy in paediatric craniopharyngiomas: a systematic review and meta-analysis of recent literature.

PURPOSES: Brachytherapy has been indicated as an alternative option for treating cystic craniopharyngiomas. Despite the difficulties regarding the complex nuclear infrastructure and consequent small number of brachytherapy studies, recent discoveries relating tumour characteristics to sensitivity to brachytherapy have stimulated this extensive systematic review and meta-analysis of the recent results aiming to summarise its efficacy and complications. METHODS: The systematic review was structured using PRISMA statements. The MEDLINE database was systematically reviewed from March 2010 to February 2021 to identify qualified trials dealing with radioisotope brachytherapy in cystic craniopharyngiomas in the paediatric population, emphasising tumour control rates and complications. RESULTS: A total of 228 individuals were analysed, of which 66 were children. The minimum average follow-up was 5 years. Considering the paediatric trials, partial and complete responses were achieved in 89% of patients with exclusively cystic lesions, compared to 58% in non-exclusively cystic lesions. The former observed progression in 3% of patients, while in the latter, 35% was reported. Visual and endocrine improvement reached 64% and 20%, respectively, in the first group, in contrast to 48% and 7% in the second group, respectively. There were similar results considering the non-exclusive paediatric series, but with less expressive numbers. CONCLUSION: These results reinforce the positive impact of radioisotope brachytherapy in the treatment of predominant monocystic or multicystic craniopharyngiomas, especially in the paediatric population, grounded by impressive tumour control rates, lower morbidities and single application in the majority of the cases. In the future, specific morphological tumour characteristics might be considered for a more assertive patient selection.

Using 14C-glyphosate to investigate the distribution of two formulations in transgenic glyphosate-resistant soybean.

Glyphosate residues in grain can be explained by the concentrations and formulations of glyphosate products. This study aimed to evaluate the residues from glyphosate formulations labeled with 14C-glyphosate applied to leaves of glyphosate-resistant soybean (GRS) in two life cycles by liquid scintillation spectrometry. Different plant tissues were analyzed after the end of the plants' life cycles. The experimental design was four repetitions of three treatments: Roundup® Original, Roundup Ready®, and unformulated glyphosate (control). The application of the dosing solution was 120 µL on the first four trifoliate leaves (10 µL per leaflet) of each plant, deposited manually with a 1-µL dispenser. All treatment solutions were calculated at a 1.2 kg a.e ha-1 of glyphosate. Glyphosate formulations of Roundup® Original and Roundup Ready® increased 14C-glyphosate distribution in GRS compared to the unformulated herbicide, regardless of the experiment (first or second cycle). Overall, the percentages of total radioactivity applied (18.33 kBq) found in grains were less than 5%. Grains, stems, and leaves showed the highest levels of herbicide residues compared to other parts of the plant. Despite the Roundup Ready® formulation having increased residues, the highest value found in grains, 1.95 mg kg-1, was less than 10 mg kg-1, the maximum residue limit (MRL) in Brazil.

BNCT research activities at the Granada group and the project NeMeSis: Neutrons for medicine and sciences, towards an accelerator-based facility for new BNCT therapies, medical isotope production and other scientific neutron applications.

The Granada group in BNCT research is currently performing studies on: nuclear and radiobiological data for BNCT, new boron compounds and a new design for a neutron source for BNCT and other applications, including the production of medical radioisotopes. All these activities are described in this report.

Pharmacokinetics of neutron-irradiated meglumine antimoniate in Leishmania amazonensis-infected BALB/c mice.

BACKGROUND: Cutaneous leishmaniasis (CL) is a parasitic disease caused by the protozoan Leishmania spp. Pentavalent antimonial agents have been used as an effective therapy, despite their side effects and resistant cases. Their pharmacokinetics remain largely unexplored. This study aimed to investigate the pharmacokinetic profile of meglumine antimoniate in a murine model of cutaneous leishmaniasis using a radiotracer approach. METHODS: Meglumine antimoniate was neutron-irradiated inside a nuclear reactor and was administered once intraperitoneally to uninfected and L. amazonensis-infected BALB/c mice. Different organs and tissues were collected and the total antimony was measured. RESULTS: Higher antimony levels were found in infected than uninfected footpad (0.29% IA vs. 0.14% IA, p = 0.0057) and maintained the concentration. The animals accumulated and retained antimony in the liver, which cleared slowly. The kidney and intestinal uptake data support the hypothesis that antimony has two elimination pathways, first through renal excretion, followed by biliary excretion. Both processes demonstrated a biphasic elimination profile classified as fast and slow. In the blood, antimony followed a biexponential open model. Infected mice showed a lower maximum concentration (6.2% IA/mL vs. 11.8% IA/mL, p = 0.0001), a 2.5-fold smaller area under the curve, a 2.7-fold reduction in the mean residence time, and a 2.5-fold higher clearance rate when compared to the uninfected mice. CONCLUSIONS: neutron-irradiated meglumine antimoniate concentrates in infected footpad, while the infection affects antimony pharmacokinetics.

Pre-feasibility Study for Establishing Radioisotope and Radiopharmaceutical Production Facilities in Developing Countries.

BACKGROUND: A significant number of developing countries have no facilities to produce medical radioisotopes and radiopharmaceuticals. OBJECTIVE: In this paper we show that access to life-saving radioisotopes and radiopharmaceuticals and the geographical distribution of corresponding infrastructure is highly unbalanced worldwide. METHODS: We discuss the main issues which need to be addressed in order to establish the production of radioisotopes and radiopharmaceuticals, which are especially important for developing countries as newcomers in the field. The data was gathered from several sources, including databases maintained by the International Atomic Energy Agency (IAEA), World Health Organization (WHO), and other international organizations; personal interactions with representatives in the nuclear medicine field from different regions of the world; and relevant literature. RESULTS: Developing radioisotope and radiopharmaceutical production program and installing corresponding infrastructure requires significant investments, both man-power and financial. Support already exists to help developing countries establish their medical radioisotope production installations from several organizations, such as IAEA. CONCLUSION: This work clearly shows that access to life-saving radioisotopes and the geographical distribution of corresponding infrastructure is highly unbalanced. Technology transfer is important as it not only immediately benefits patients, but also provides employment, economic activity and general prosperity in the region to where the technology transfer is implemented.

Pharmacokinetics of neutron-irradiated meglumine antimoniate in Leishmania amazonensis-infected BALB/c mice

Background:Cutaneous leishmaniasis (CL) is a parasitic disease caused by the protozoan Leishmania spp. Pentavalent antimonial agents have been used as an effective therapy, despite their side effects and resistant cases. Their pharmacokinetics remain largely unexplored. This study aimed to investigate the pharmacokinetic profile of meglumine antimoniate in a murine model of cutaneous leishmaniasis using a radiotracer approach.Methods:Meglumine antimoniate was neutron-irradiated inside a nuclear reactor and was administered once intraperitoneally to uninfected and L. amazonensis-infected BALB/c mice. Different organs and tissues were collected and the total antimony was measured.Results:Higher antimony levels were found in infected than uninfected footpad (0.29% IA vs. 0.14% IA, p = 0.0057) and maintained the concentration. The animals accumulated and retained antimony in the liver, which cleared slowly. The kidney and intestinal uptake data support the hypothesis that antimony has two elimination pathways, first through renal excretion, followed by biliary excretion. Both processes demonstrated a biphasic elimination profile classified as fast and slow. In the blood, antimony followed a biexponential open model. Infected mice showed a lower maximum concentration (6.2% IA/mL vs. 11.8% IA/mL, p = 0.0001), a 2.5-fold smaller area under the curve, a 2.7-fold reduction in the mean residence time, and a 2.5-fold higher clearance rate when compared to the uninfected mice.Conclusions:neutron-irradiated meglumine antimoniate concentrates in infected footpad, while the infection affects antimony pharmacokinetics.(AU)

Pharmacokinetics of neutron-irradiated meglumine antimoniate in Leishmania amazonensis-infected BALB/c mice

Cutaneous leishmaniasis (CL) is a parasitic disease caused by the protozoan Leishmania spp. Pentavalent antimonial agents have been used as an effective therapy, despite their side effects and resistant cases. Their pharmacokinetics remain largely unexplored. This study aimed to investigate the pharmacokinetic profile of meglumine antimoniate in a murine model of cutaneous leishmaniasis using a radiotracer approach. Methods: Meglumine antimoniate was neutron-irradiated inside a nuclear reactor and was administered once intraperitoneally to uninfected and L. amazonensis-infected BALB/c mice. Different organs and tissues were collected and the total antimony was measured. Results: Higher antimony levels were found in infected than uninfected footpad (0.29% IA vs. 0.14% IA, p = 0.0057) and maintained the concentration. The animals accumulated and retained antimony in the liver, which cleared slowly. The kidney and intestinal uptake data support the hypothesis that antimony has two elimination pathways, first through renal excretion, followed by biliary excretion. Both processes demonstrated a biphasic elimination profile classified as fast and slow. In the blood, antimony followed a biexponential open model. Infected mice showed a lower maximum concentration (6.2% IA/mL vs. 11.8% IA/mL, p = 0.0001), a 2.5-fold smaller area under the curve, a 2.7-fold reduction in the mean residence time, and a 2.5-fold higher clearance rate when compared to the uninfected mice. Conclusions: neutron-irradiated meglumine antimoniate concentrates in infected footpad, while the infection affects antimony pharmacokinetics.(AU)

Cyclotron production of 67Cu: A new measurement of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga nuclear cross sections / Producción de 67Cu en ciclotrón: una nueva medición de secciones eficaces nucleares de 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga

Abstract The cross sections of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to alow-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%)was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga.Nuclear cross sections were measured in the energy range 35-70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the nuclear reaction code TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.

Resumen Las secciones eficaces de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga se midieron en la instalación ARRONAX utilizando el ciclotrón 70 MeV, con especial atención a la producción del radionucleidos teranóstico 67Cu. El material enriquecido 68Zn se galvanizó sobre soporte de plata y se expuso a un haz de protones de baja intensidad utilizando un blanco de láminas apiladas. Como los radionucleidos 67Cu y 67Ga tienen periodos de semidesintegración y líneas γ similares (ambos se desintegran a 67Zn), un proceso radioquímico dirigido a la separación Cu / Ga fue obligatorio para evitar interferencias en las mediciones de espectrometría γ. Se desarrolló un procedimiento químico simple con una alta eficiencia de separación (> 99%) durante cada procesamiento de la lámina, gracias a los isótopos trazadores 61Cu y 66Ga. Las secciones eficaces nucleares se midieron en el rango de energía de 35-70 MeV utilizando reacciones de referencia recomendadas por el Organismo Internacional de Energía Atómica (OIEA) para monitorear el flujo del haz. Al comparar con los datos de la literatura, se observó una buena concordancia en general con la tendencia de las reacciones nucleares, particularmente con las últimas mediciones, pero se obtuvieron valores ligeramente inferiores en el caso de 67Cu. Los resultados experimentales de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga también se compararon con los valores teóricos estimados usando el código de reacción nuclear TALYS. El rendimiento de producción del radionucleido teranóstico 67Cu se estimó considerando los resultados obtenidos en este trabajo.

Cyclotron production of 67Cu: A new measurement of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga nuclear cross sections

The cross sections of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to alow-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%)was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga.Nuclear cross sections were measured in the energy range 35-70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the nuclear reaction code TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.

Las secciones eficaces de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga se midieron en la instalación ARRONAX utilizando el ciclotrón 70 MeV, con especial atención a la producción del radionucleidos teranóstico 67Cu. El material enriquecido 68Zn se galvanizó sobre soporte de plata y se expuso a un haz de protones de baja intensidad utilizando un blanco de láminas apiladas. Como los radionucleidos 67Cu y 67Ga tienen periodos de semidesintegración y líneas γ similares (ambos se desintegran a 67Zn), un proceso radioquímico dirigido a la separación Cu / Ga fue obligatorio para evitar interferencias en las mediciones de espectrometría γ. Se desarrolló un procedimiento químico simple con una alta eficiencia de separación (> 99%) durante cada procesamiento de la lámina, gracias a los isótopos trazadores 61Cu y 66Ga. Las secciones eficaces nucleares se midieron en el rango de energía de 35-70 MeV utilizando reacciones de referencia recomendadas por el Organismo Internacional de Energía Atómica (OIEA) para monitorear el flujo del haz. Al comparar con los datos de la literatura, se observó una buena concordancia en general con la tendencia de las reacciones nucleares, particularmente con las últimas mediciones, pero se obtuvieron valores ligeramente inferiores en el caso de 67Cu. Los resultados experimentales de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga también se compararon con los valores teóricos estimados usando el código de reacción nuclear TALYS. El rendimiento de producción del radionucleido teranóstico 67Cu se estimó considerando los resultados obtenidos en este trabajo.

Localización radioguiada de lesiones no palpables y ganglio centinela en estadios iniciales de Cáncer de Mama (snoll). Primera experiencia en el Hospital Italiano de Buenos Aires / Radioguided non-palpable lesion localization and sentinel lymph node mapping (snoll) at early breast carcinoma. First experience at Hospital Italiano de Buenos Aires

Introducción Actualmente, entre un 25 y un 35% de los cánceres de mama se diagnostican como lesiones no palpables. La detección de lesiones cada vez más pequeñas exige el desarrollo de nuevas técnicas prequirúrgicas de marcación y localización. Presentamos la experiencia del Hospital Italiano de Buenos Aires con la técnica de localización radioguiada de lesiones no palpables y ganglio centinela (snoll). Objetivos El objetivo de este trabajo es describir las características clínico-patológicas de las pacientes sometidas a dicha técnica y las ventajas, desventajas, complicaciones y resultados en términos de márgenes libres, tasa de retumorectomías, volumen tumoral resecado y tiempo quirúrgico. Material y método Se trata de un estudio observacional, retrospectivo. Se incluyeron todas las pacientes con carcinomas no palpables en quienes se llevó a cabo la técnica de snoll entre el 1 de agosto de 2016 y el 4 de mayo de 2017. Resultados Se incluyó un total de 25 pacientes, todas con diagnóstico previo de carcinoma de mama invasor a través de una punción histológica. Utilizando la técnica snoll, se logró identificar la lesión de mama en el 96% de las pacientes. En el 100% de las pacientes, los márgenes quirúrgicos estaban libres de lesión, por lo que no se realizaron retumorectomías. Se identificó el 100% de los ganglios centinelas, 76% mediante la técnica snoll y 24% mediante la inyección previa del colorante Azul Patente. Conclusiones La técnica snoll demostró ser una técnica sencilla, que mejora el confort de la paciente y que presenta resultados comparables con las técnicas tradicionales. Si bien se trata de una primera experiencia, son alentadores los resultados en términos de márgenes libres, tiempo quirúrgico y volumen resecados.

Introduction Currently, about 25 to 35% of all breast tumors are diagnosed at a nonpalpable stage. The increasing ability to detect small lesions consequently demands the development of novel technology for preoperative lesion identification and intraoperative localization. In this study, we present our initial experience using Sentinel Node Occult Lesion Localization (snoll) at the Hospital Italiano de Buenos Aires. Objectives The objective of this study is to describe clinical and pathological characteristics of patients who were submitted to snoll technique and the advantages and disadvantages, complications and results in terms of tumor-free margins, subsequent surgery rate, total specimen volume and surgical time. Materials and method This is a retrospective, observational study. We included all patients with non-palpable breast cancer who were submitted to surgery and snoll technique between August 1st, 2016 and March 14th, 2017. Results A total of 25 patients were included in this study. All patients had previous diagnosis of invasive breast cancer by core needle biopsy. The breast lesion was correctly identified in 96% of patients through snoll. Surgical margins were tumor-free in all patients. No patients required subsequent surgery. All sentinel nodes were correctly identified. In 76% of cases, snoll was sufficient and in 24% additional injection of patent blue was required. Conclusions In our experience, snoll has proven to be a simple technique that improves patient comfort and shows comparable results when compared to traditional identification methods. Although these are our initial results, we believe our findings to be promising in terms of adequacy of margins, surgical time and total specimen volume.

USE OF 125IODINE SEEDS (ROLLIS) FOR INTRA-OPERATIVE LOCALIZATION OF NONPALPABLE BREAST LESIONS: ANALYSIS OF THE IMPLANT OF 338 SEEDS IN 284 PATIENTS / Uso de sementes de iodo-125 (ROLLIS) para localização intraoperatória de lesões impalpáveis da mama: análise do implante de 338 sementes em 284 pacientes

Objective: To analyze the feasibility, efficacy and results of the use of 125Iodine seeds for intra-operative localization of nonpalpable breast lesions. Method: Retrospective review of 284 patients, referred by various breast specialist surgeons, with radiologically detected but clinically nonpalpable microcalcifications or nodules, submitted to pre-operatory 125Iodine seed implant, between July 2012 and September 2016. A total of 338 seeds were implanted in ordinary radiologic departments, supported by ultrasonography or mammography exams, chosen according to the morphologic aspect of the lesion. Radioguided surgical procedure took place on the same day or few days after the implant of the seeds, with the help of a radiation detector called Gamaprobe, which directs the surgeons towards the radioactive seeds and to the lesion to be resected. Results: All implants were performed as outpatient procedures, with patients immediately returning to their daily activities. No complications such as pain, bleeding, infeccion and haematoma were recorded. Pathologists had no difficulty in preparing the surgical specimens for histopathologic analysis. Surgical safety margins were considered adequate in all pathologic reports, with no need for re-operations. The healing process was not jeopardized by radiation, and the surgeons were pleased with the improvement on intraoperative lesions localizations and shortening on operatory time. Cosmetic results were well accepted by the patients. Conclusion: The 125Iodine seed implant is an effective alternative method for intraoperative localization of radiologically detectable and clinically nonpalpable breast lesions.

Objetivo: Avaliar a exequibilidade e a eficácia do método de implante de sementes de 125Iodo (ROLLIS) para localização intraoperatória de lesões impalpáveis da mama. Método: Trata-se de um estudo retrospectivo, incluindo 284 pacientes com nódulos ou microcalcificações mamárias, visíveis na mamografia e/ou ultrassonografia, porém, clinicamente impalpáveis, submetidas a implantes de sementes de 125Iodo, de julho de 2012 a setembro de 2016, sendo implantado um total de 338  sementes. As  pacientes foram encaminhadas por diversos mastologistas que executaram cirurgias radioguiadas com auxílio de detector de radiação denominado Gamaprobe, realizadas no mesmo dia do implante ou vários dias após, seguindo a agenda do centro cirúrgico, da equipe médica e a conveniência da paciente. Resultados: Os implantes foram realizados em regime ambulatorial, com imediato retorno das pacientes às atividades cotidianas, não sendo registrada qualquer complicação como dor, hemorragia, infecção ou hematoma. Os patologistas não constataram prejuízo no processamento do espécimen cirúrgico. O processo cicatricial se efetuou normalmente, obtendo-se plena satisfação por parte dos cirurgiões, que referiram maior facilidade na localização intraoperatória das lesões e diminuição no tempo operatório. O resultado cosmético também foi beneficiado, sendo bem aceito pelas pacientes. As margens cirúrgicas foram consideradas adequadas em todos os casos, graças à avaliação feita pelo patologista e às ampliações executadas no momento da cirurgia, dispensando re-excisões. Conclusão: O implante de sementes de 125Iodo (ROLLIS) é uma técnica segura e eficaz para localização intraoperatória de lesões radiologicamente visíveis, porém clinicamente impalpáveis, da mama.

Evaluación de riesgos asociados a la producción de generadores de Molibdeno-99/Tecnecio-99m / Risk analysis applied to the production of generators of Molybdenum-99/Technetium-99m

El Tecnecio-99m es el radionúclido más utilizado en la actualidad en el campo de la medicina nuclear. El Centro Nacional de Seguridad Nuclear (CNSN) como órgano regulador de Cuba requiere la realización de análisis de riesgo a las instalaciones con peligro radiológico potencial asociado y preferentemente, que estos análisis sean realizados mediante el método de matriz de riesgo. Aunque existen varios métodos cualitativos o cuantitativos para realizar estos estudios, la existencia de bases de riesgo de partida y de códigos de análisis, así como la simplicidad de su empleo han privilegiado la matriz de riesgo como método semicuantitativo predominante. El artículo presenta los resultados de la aplicación de este método para la evaluación de los riesgos asociados a la producción de generadores de Molibdeno-99/Tecnecio-99m, que se realiza en el Centro de Isótopos (CENTIS). Empleando el código SECURE-MR Ver. 2.0 se realiza el análisis de riesgo detallado de la práctica. Se identificaron tres secuencias accidentales con nivel de riesgo alto y se determinó la importancia de barreras y reductores relacionados con factores humanos por suficiencia y capacitación de personal. Entre las aplicaciones derivadas del estudio se reportaron capacidades novedosas de análisis, así como posibilidades de monitoreo del riesgo. El modelo de riesgo desarrollado para el proceso de producción de generadores de Molibdeno-99/Tecnecio-99m unido a las capacidades de revisión, análisis y documentación ofrecidas por la herramienta permitieron la obtención de un documento coherente con el modelo, que constituye, además, una base de conocimientos efectiva para la evaluación de la seguridad de la instalación

Technetium-99m is the most commonly used radionuclide in the field of nuclear medicine. The National Center for Nuclear Safety (NCNS), as the regulatory body of Cuba, requires the carrying out of risk analysis for facilities with associated radiological hazard potential and, preferably, that these analyzes be performed using the risk matrix method. Although there are several qualitative or quantitative methods to perform these studies, the existence of basis risk starting and analysis codes and simplicity of use has been privileged the risk matrix as a predominant semi-quantitative method. The paper presents the results of the application of this method for the evaluation of the risks associated with the production of Molybdenum-99/Technetium-99m generators, which is carried out at the Isotope Center (Centis). Using the SECURE - MR Ver. 2.0 code a detailed risk analysis of its practice was carried out. Three accidental sequences of high-level risks were identified and the importance of barriers and reducers related to human factors associated to sufficiency and staff training was determined. Among the derived applications novel analysis capacities as well as risk monitoring possibilities are reported. The risk model developed for the production process of Molybdenum-99/Technetium-99m generators, joined with the ability to review, analyze and all the documentation provided by the tool, allow obtaining a completely and coherent document with the model, which constitutes an effective basis the safety of the facility

Gynecological brachytherapy for postoperative endometrial cancer: dosimetric analysis (Ir-192 vs Co-60).

INTRODUCTION: Endovaginal brachytherapy treatment dosimetry differences were studied using Ir-192 or Co-60 sources for postoperative endometrial cancer. MATERIALS AND METHODS: A prospective descriptive study was conducted. Thirty-six dosimetry plans of different patients were studied (15 by Ir-192 and 21 by Co-60). Variables studied included D2cc Rectum, D2cc Bladder, D2cc Sigmoid, dose percentage at point 0 (applicator surface on the top of the cylinder) and dose percentage at point 1 (5 mm deep on the top of the cylinder). A comparative analysis was performed of the values obtained from each variable between Ir-192 and Co-60 treatments. We compared average of each variables between Iridium and Cobalt by T Student for independent samples (SPSS 22). RESULTS: There were no significant differences on using Ir-192 or Co-60 by variables, except for dose percentage at point 1 in which we detected significant differences (Table 1). Table 1 The results Variables Sources Iridium 192 Cobalt 60 D2cc Rectum (mean dose) [rank] 6.01 Gy [3.99-7.90] 5.28 Gy [3.87-6,34] D2cc Bladder (mean dose) [rank] 5.82 Gy [4.20-8.38] 5.05 Gy [2.23-6.95] D2cc Sigmoid (mean dose) [rank] 4.43 Gy [1.66-6.67] 2.33 Gy [0.60-4.28] Dose percentage at point 0a (mean) [rank] 210.74% [120.90-234.90] 204.75% [177.10-223] Dose percentage at point 1b (mean) [rank] 93.49% [87.30-100.60] 100.11% [96.70-102] aPoint 0: point to the applicator surface bPoint 1: point to 5 mm applicator surface DISCUSSION: Brachytherapy treatment dosimetry plans are similar using Ir-192 or Co-60, except dose percentage at point 1. In the scientific literature, some differences exist and there are some advantages in using cobalt.

Cisternografía radioisotópica con 99Tc-DTPA para confirmación diagnóstica de la hidrocefalia oculta normotensa / 99 Tc-DTPA radionuclide cisternography to confirm the diagnosis of normal pressure hydrocephalus

Se presenta el caso clínico de una paciente que ingresó en el Hospital Clinicoquirúrgico Hermanos Ameijeiras con antecedentes de etilismo crónico y cuadro clínico progresivo de deterioro cognitivo-conductual, trastornos de la marcha y esfinterianos, a quien se le realizó una cisternografía radioisotópica con el objetivo de comprobar su eficacia en el estudio de la dinámica del líquido cefalorraquídeo para diagnosticar la hidrocefalia oculta normotensa. La resonancia magnética de cráneo evolutiva evidenció hidrocefalia y la cisternografía radioisotópica confirmó el diagnóstico de hidrocefalia oculta normotensa. A la paciente se le realizó una derivación ventrículo peritoneal con la que se obtuvo una respuesta clínica evolutiva favorable. Se concluye que la cisternografía radioisotópica continúa siendo una herramienta útil para confirmar este diagnóstico y predecir la respuesta al tratamiento derivativo(AU)

A female patient who was admitted to Hermanos Ameijeiras Clinical and Surgical Hospital is presented here. She had a history of chronic alcohol abuse and progressive clinical deterioration of cognitive behavioral, abnormal gait and sphincter disorders. This patient had a radioisotope cisternography in order to test its effectiveness in the study of the dynamics of cerebrospinal fluid, and to diagnose normotensive hidden hydrocephalus. This MRI revealed hydrocephalus and skull evolutionary radioisotope cisternography confirmed the diagnosis of normal pressure hidden hydrocephalus. This patient received a shunt with a favorable evolutionary clinical response. It is concluded that cisternography radioisotope remains a useful tool to confirm this diagnosis and predict response to derivative treatment(AU)

The study of natural and artificial radionuclides incorporation in teeth and head bones of animals lived nearby Caetité uranium mine, Brazil.

This study aimed at assessing the incorporation of radionuclides in animals in the proximity of the uranium mine in Caetité, Brazil. In 2014, samples of bovine and equine teeth and skull bones were collected and their contents of natural and artificial isotopes were assessed using nuclear spectrometry techniques. Gamma ray emission from 226,228Ra and 40K isotopes was determined using high-purity germanium (HPGe) spectrometry, 90Sr radioactivity was measured with liquid scintillation, and 234,238U, 232,230,228Th, 210Po and 239+240Pu radioactivity was assessed with alpha-spectrometry. Prior to the measurements, sample dissolutions and isotope separations were performed. Our results indicate a high 228Th isotope content in the skull bones and the teeth of animals, up to 179 Bq per kg of ash. The 226Ra and 228Ra concentrations were slightly lower. Activity concentrations of other isotopes were significantly lower or below the detection limit. We could not identify sources of technologically enhanced levels of 228Ra in the area we investigated; therefore we suggest that their origin is natural.

20 años de investigaciones y aplicaciones en Cuba de los radiotrazadores y el perfilaje en la industria y el medioambiente / 20 years of Cuban radiotracer and scanning researches and applications at the industry and the environment

Las tecnologías de radiotrazadores y de escaneo son herramientas bien consolidadas para el estudio, análisis y evaluación de los procesos industriales y medioambientales. En este trabajo se sintetizan los principales resultados alcanzados por el Grupo de Aplicaciones Industriales y Medioambientales de los Radiotrazadores en el Departamento de Radioquímica. La tecnología de radiotrazadores se ha empleado con éxito para la caracterización del mezclado en reactores discontinuos, los estudios sobre el comportamiento del 99mTc en aguas naturales y residuales, la calibración y validación del modelo de calidad de agua del río Almendares, la caracterización de un reactor anaerobio para el tratamiento de los residuales en el CAI “Pablo Noriega”, la verificación y validación del modelo DFC en un cristalizador azucarero, el desarrollo de un generador radisotópico de ? / ?, la modelación de la calidad del agua en el segmento medio del río Luyanó, y para la modelación de la calidad del agua en el río Guaire, Caracas, Venezuela. En los últimos años el grupo ha desarrollado y evaluado a nivel de laboratorio radiotrazadores para fluidos orgánicos, particularmente relacionados con la industria del petróleo y para sólidos, empleando como precursor al ?. Mientras la técnica de escaneo se ha utilizado para el perfilaje gamma en torres de destilación de alcohol de los CAI "Héctor Molina”“Heriberto Duquesne" y "Jesús Rabí".

Mercury methylation in sediments of a Brazilian mangrove under different vegetation covers and salinities.

The presence and formation of methylmercury (MMHg), a highly toxic form of Hg, in mangrove ecosystems is poorly studied. Therefore the aim of this study was to evaluate mercury methylation potentials in sediment, litter and root samples (Avicennia shaueriana and Spartina alterniflora) from different regions of a mangrove ecosystem, as well as the influence of salinity on methylation. Sediment was sampled under different depths and in mangrove regions with different plant covers and salinities. All samples were incubated with (203)Hg and MM(203)Hg was extracted and measured by liquid scintillation. MMHg was formed in all samples and sites tested including plant roots and litter. Higher Hg methylation was found in the superficial fraction of sediments (0.47-7.82%). Infralittoral sandy sediment had low MMHg formation (0.44-1.61%). Sediment under Rhizophora mangle had lower MMHg formation (0.018-2.23%) than under A. shaueriana (0.2-4.63%) and Laguncularia racemosa (0.08-7.82). MMHg formation in sediment tended to increase with salinity but the differences were not significant. Therefore, MMHg formation occurs in different sites of mangrove ecosystems and may be an important threat that requires further study.

Robust biological nitrogen fixation in a model grass-bacterial association.

Nitrogen-fixing rhizobacteria can promote plant growth; however, it is controversial whether biological nitrogen fixation (BNF) from associative interaction contributes to growth promotion. The roots of Setaria viridis, a model C4 grass, were effectively colonized by bacterial inoculants resulting in a significant enhancement of growth. Nitrogen-13 tracer studies provided direct evidence for tracer uptake by the host plant and incorporation into protein. Indeed, plants showed robust growth under nitrogen-limiting conditions when inoculated with an ammonium-excreting strain of Azospirillum brasilense. (11)C-labeling experiments showed that patterns in central carbon metabolism and resource allocation exhibited by nitrogen-starved plants were largely reversed by bacterial inoculation, such that they resembled plants grown under nitrogen-sufficient conditions. Adoption of S. viridis as a model should promote research into the mechanisms of associative nitrogen fixation with the ultimate goal of greater adoption of BNF for sustainable crop production.

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 ...