Comparison of Whole-Body Dosimetry Measurements in 131I Therapy Using Ceiling-Mounted Geiger-Müller Detectors and γ-Camera Scans: An Agreement Analysis.

Background: In 131I therapies internal dosimetry is crucial for determining the mean absorbed dose to organs at risk, particularly the bone marrow, which has a dose constraint of 2 Gy. Traditionally, multicompartmental models have been used for bone marrow dosimetry, necessitating whole-body absorbed-dose assessments. However, noninvasive techniques, such as γ-camera scans or ceiling-mounted Geiger-Müller (GM) counters, can estimate the aforementioned. This study was aimed to evaluate the agreement between whole-body mean absorbed dose using γ-camera scans and ceiling-mounted GM in patients with thyroid carcinoma undergoing 131I therapy. Methods: This study included 31 patients with thyroid cancer who were treated with 131I. The whole-body time-integrated activity (TIA) and mean absorbed dose were estimated using the elimination curves obtained with γ-camera scans and ceiling-mounted GM. In addition, statistical analysis was performed on the data to determine the Coefficient Correlation Coefficient and the Bland-Altman limits of agreement for both parameters, as well as for the elimination curves' effective half-life. Results: The study revealed correlations of 0.562 and 0.586 between whole-body TIA and mean absorbed dose, respectively. The Bland-Altman limits of agreement were found to be below -3.75% and within 12.75% of the bone marrow dose constraint of 2 Gy. The nonparametric evaluation revealed that whole-body TIA and mean absorbed dose medians from GM were lower than those from γ-camera scans (p < 0.001). Effective half-life estimation mean was significantly lower in the GM than in the γ-camera of 13 and 23 h. Conclusions: Although GM calculates the whole-body absorbed dose with margins of error within clinical acceptance, underestimation of the effective half-life makes it an unacceptable substitute method for γ-cameras in clinical practice. Further research should be conducted to evaluate single-point GM measurement substitutions in time-activity curves.

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

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.

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.

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.

Eficacia de lutecio-177 DOTATATE/TOC en pacientes con tumores neuroendocrinos bien diferenciados en estado avanzado. Ensayo clínico fase II / Efficacy of Lutetium-177 DOTATATE/TOC in Advanced Neuroendocrine Tumors

Resumen Introducción: En 2009, el Instituto Nacional de Cancerología (INC) elaboró el 177Lu-DOTATATE/TOC. El propósito del estudio fue demostrar la eficacia de estos radiopéptidos en el tratamiento paliativo de pacientes con tumores neuroendocrinos (TNE) avanzados inoperables (metastásicos o localmente avanzados) y en progresión. Métodos: Ensayo clínico abierto fase II de un solo brazo en 13 pacientes adultos con TNE grado 1 o 2, con expresión de receptores de somatostatina en lesiones blanco demostrada por captación Krenning 3 o 4 en 99mTc-HYNIC TOC. Los pacientes fueron tratados con 177Lu-DOTATATE o 177Lu-DOTATOC (según disponibilidad) a una actividad acumulativa proyectada de 600-800 mCi dividida en 3-4 dosis cada 6-9 semanas comenzando siempre con una actividad fija de 200 mCi y dosimetría con la primera dosis. El desenlace primario fue la respuesta objetiva calculada 6 y 12 meses después de la última dosis del tratamiento. Resultados: Se incluyeron 13 pacientes (7 mujeres) de 63 ± 11,6 años con TNE avanzado inoperable y en progresión. La actividad final administrada fue de 800 mCi, 600 mCi, 400 mCi y 200 mCi en 4, 7, 1 y 1 pacientes, respectivamente. La tasa de control de enfermedad a 6 y 12 meses fue de 69,2% y 45,5%, respectivamente, logrando únicamente enfermedad estable. Fallecieron 7 pacientes, 2 de ellos en los primeros 6 meses. La mediana de supervivencia global a partir de la última dosis del radiopéptido fue de 15,7 meses. Conclusiones: Se corroboró la eficacia y la seguridad del tratamiento con los radiopéptidos en NETs avanzados.

Abstract Objectives: The National Cancer Institute first elaborated 177Lu-DOTATATE/TOC in 2009. The purpose of this study was to prove the efficacy of these radiopeptides in the palliative treatment of patients with progressive advanced inoperable neuroendocrine tumors (NETs). Methods: A single-phase phase II open clinical trial was conducted in 13 adult patients with grade 1 y 2 NETs, with expression of somatostatin receptors in target lesions proven by Krenning Score 3 or 4 uptake in 99mTc-HYNIC TOC. Patients were treated with 177Lu-DOTATATE or 177Lu-DOTATOC (depending upon availability) at a projected acumulative activitiy of 600-800 mCi divided into 3-4 doses every 6-9 weeks always beginning with a fixed activity of 200 mCi and dosimetry during the first dose. The primary outcome was objective response to therapy. Results: 13 patients (7 women) aged 63 ± 11.6 years with inoperable advanced NETs were included. The final therapeutic administered activity was 800 mCi, 600 mCi, 400 mCi and 200 mCi in 4, 7, 1 and 1 patients, respectively. The disease control rate at 6 and 12 months was 69.2% and 45.5%, respectively, only obtaining stable disease. Six patients died, 2 of them in the first 6 months. Median overall survival was 15.7 months from the last treatment dose. Conclusions: The efficacy of the treatment with 177Lu-DOTATATE or 177Lu-DOTATOC radiopeptides elaborated in-house was confirmed, becoming a management alternative for patients with advanced NETs.

Impulse oscillometry reference values and bronchodilator response in three- to five-year old children living at high altitude.

INTRODUCTION: Impulse oscillometry (IOS) is used to measure airway impedance. It is an effective tool for diagnosing and treating respiratory diseases, and it has the advantage that it does not require forced respiratory maneuvers. IOS reference values are required for each population group. OBJECTIVE: This study aimed to determine the IOS reference values and bronchodilator response in healthy preschool children living in Bogotá, Colombia. METHODS: We performed a cross-sectional study in preschool children who had no history of respiratory disease; 96 children fit the parameters for testing to determine normal values according to the American Thoracic Society and European Respiratory Society criteria. RESULTS: Values for respiratory resistance (Rrs) and reactance (Xrs) at 5, 10, and 20 Hz, respiratory impedance (Zrs, and resonance frequency (Fres) were established. Height was the most influential independent variable for IOS values; an increase in height led to a reduction in Rrs5 and Rrs20 and an increase in Xrs5. After the administration of 400 mcg of salbutamol the values for Rrs5(-17.48%), Rrs20(-8.63%), Fres (-10.68%), and area of reactance (-35.44%) were reduced, meanwhile Xrs5 (15.35%) was increased. CONCLUSIONS: Normal IOS values before and after the administration of 400 mcg of salbutamol were determined for a population of children aged 3-5 years at 2,640 m. Reference IOS equations for these children are presented. A relative change of up to -28% and 36% after the use of salbutamol for respiratory resistance and reactance, respectively, should be considered as an upper limit of the normal range, and possible appropriate cut-off values for defining significant response for evaluating therapeutic interventions.

Secondary erythrocytosis due to hypoxemia as prognosis in exacerbated chronic pulmonary diseases / Eritrocitosis secundaria a hipoxemia como pronóstico en neumopatías crónicas exacerbadas

Abstract Introduction: Even though exacerbations are the main cause of emergency consultation in patients suffering from lung diseases, erythrocyte parameters are not assessed in their prognosis. Thus, determining the implications of erythrocyte parameters might contribute to define the usefulness of phlebotomy or red blood cells transfusion in these patients. Objective: To establish a possible relationship between the different hematocrit levels with a 30-day prognosis in patients admitted with exacerbated chronic lung disease and hypoxemia. Materials and methods: A study based on a 30- day follow-up was conducted. Variables were described using an additional categorization by hematocrit levels and an adjustment in a multivariate model through logistic regression. Results: Follow-up was completed for 110 Patients. The frequency of anemia was 7.3% and of erythrocytosis, 14.5%. A significant association to the outcome using Anthonisen score (OR=10.45, 95%CI: 1.11-98.48, p=0.04), hypertension (OR=11.02, 95%CI: 1.32-91.75, p=0.026) and heart failure (OR=0.09, 95%CI: 0.01-0.82, p=0.032) was found. Conclusion: This research could not determine any relationship between erythrocyte parameters and prognosis of patients suffering from pulmonary diseases; nevertheless, extreme values of hematocrits tended to have adverse outcomes.

Resumen Introducción. Aunque las exacerbaciones de las neumopatías crónicas son las principales causas de consulta a urgencias de los pacientes que las padecen, los parámetros eritrocitarios no son evaluados en su pronóstico. Por tanto, determinar las implicaciones de los parámetros eritrocitarios podría ayudar a definir la utilidad de la flebotomía o la transfusión de eritrocitos en estos pacientes. Objetivo. Establecer si hay relación entre los distintos niveles de hematocrito con pronóstico a 30 días en pacientes con neumopatía crónica exacerbada e hipoxemia. Materiales y métodos. Estudio de seguimiento a 30 días. Se realizó la descripción de las variables con una categorización adicional por niveles de hematocrito y un ajuste en un modelo multivariado por regresión logística. Resultados. Se completó el seguimiento en 110 pacientes. La frecuencia de anemia fue de 7.3% y de eritrocitosis de 14.5%. Se encontró asociación significativa al desenlace con la clasificación Anthonisen (OR=10.45, IC95%: 1.11-98.48; p=0.04), hipertensión arterial (OR=11.02, IC95%: 1.32-91.75; p=0.026) y falla cardiaca (OR=0.09, IC95%: 0.01-0.82; p=0.032). Conclusión. Este estudio no pudo determinar relación alguna entre los parámetros eritrocitarios y el pronóstico de pacientes con enfermedades pulmonares crónicas; sin embargo, hubo una tendencia a que los valores extremos del hematocrito presentaran desenlaces adversos.

Eritrocitosis secundaria a hipoxemia en neumopatías crónicas: de la reología a la práctica clínica / Erythrocytosis Secondary to Hypoxemia in Chronic Lung Diseases: From Rheology to Clinical Practice

La eritrocitosis es una condición infrecuente en las enfermedades pulmonares crónicas que cursan con hipoxemia; su adecuada aproximación fisiopatológica y clínica no es bien conocida. Aunque la eritrocitosis es una respuesta compensatoria frente a la hipoxemia, sus efectos en la microcirculación pueden afectar parámetros cardiovasculares con deterioro de la sintomatología de pacientes con esta patología. La corrección por medio de la flebotomía puede ser una medida terapéutica útil, pero no hay claridad sobre su indicación en consideración a la evidencia actualmente disponible; de igual forma, existen preocupaciones sobre los desenlaces adversos que podrían generarse con su uso en la reología y en la ferrocinética. Es también desconocida la pertinencia de la flebotomía ante el aparente pronóstico benigno de quienes presentan eritrocitosis en el contexto de una neumopatía crónica. Con la escasa información actual, se hace necesaria la ampliación de la investigación en los tópicos relacionados con la eritrocitosis debida a hipoxemia.

Erythrocytosis is a rare condition in chronic lung diseases associated to hipoxemia. It's proper clinical and pathophysiological approach is not very well known. Although erythrocytosis is a compensatory response against hypoxemia, its effects on microcirculation may affect cardiovascular parameters with symptomatic disrepair in patients with this disease. Correction of erythrocytosis through phlebotomy may be a useful therapeutic approach, but there is no clearness about its indication considering the current evidence available; likewise, there are concerns about adverse outcomes that could be generated with its use in rheology and ferrokinetics. It is also unknown the relevance of phlebotomy with regard to the apparent benign prognosis of patients presenting with erythrocytosis in chronic lung diseases. With the scarce current information it is necessary to expand the research on issues related to erythrocytosis due hypoxemia.

Caracterización del conocimiento en cuidado paliativo pediátrico y percepción debarreras por parte de los pediatras y residentes de pediatría / Knowledge of pediatric palliative care and perception of barriers by pediatricians and pediatric residents

INTRODUCCIÓN: El incremento de enfermedades crónicas y limitantes para la vida, crea un desafío ético y una invitación a desarrollar un nuevo tipo de atención: la medicina paliativa. OBJETIVO: Documentar la percepción de pediatras y residentes de pediatría acerca de su conocimiento en cuidado paliativo pediátrico, e identificar las principales barreras percibidas por ellos. Materiales y MÉTODOS: Encuesta a pediatras generales, subespecialistas de pediatría y residentes de pediatría de Colombia. Estudio de corte transversal analítico. Nivel de significancia del 5%, y confianza del 95%. RESULTADOS: Participaron 359 pediatras y residentes de pediatría de todo el país. Solo el 13% ha recibido entrenamiento en cuidado paliativo, 57,1% a través de un compañero o autoaprendizaje. Hubo asociación estadísticamente significativa entre entrenamiento en cuidado paliativo y nivel de formación, años de ejercicio profesional y pacientes referidos en el último año. Se evidenció mayor conocimiento y confort en aquellos que han recibido entrenamiento.como principales barreras se encontraron: tiempo limitado para la atención, miedo al enfrentar la muerte del niño y deseo de los familiares de mayor intervención que el equipo médico. CONCLUSIONES: La mayoría de los encuestados no ha recibido entrenamiento en cuidado paliativo a pesar de considerarlo pertinente y percibir que generalmente se encuentran en situaciones poco confortables al respecto

INTRODUCTION: The rise of chronic and life threatening disease creates an ethical challenge and an invitation to develop a new type of care: palliative medicine. OBJECTIVE: The aim was to determine pediatricians and pediatric residents perceptions of their knowledge of pediatric palliative care, and identify the main barriers perceived by them. MATERIALS AND METHODS: General pediatricians, pediatric medical sub-specialists, and pediatric residents in Colombia took part in an analytical cross-sectional study using a questionnaire. Significance test results were reported with 95% confidence intervals. RESULTS: A total of 359 pediatricians and pediatric residents across the country completed the survey. Only 13% had received training in palliative care, with 57.1% through a peer or self-study. There was a significant relationship between palliative care training and level of education, years of practice, and patients referred in the last year. Greater knowledge and comfort in those who have received training was evident. The main barriers identified were: limited time for care, fear facing children's death, and families demanding more intervention by the physicians. CONCLUSIONS: Most respondents had not received training in palliative care, even when they see it as relevant, and were typically uncomfortable when facing situations on this type of care

Reporting of methodologic information on trial registries for quality assessment: a study of trial records retrieved from the WHO search portal.

BACKGROUND: Although randomized clinical trials (RCTs) are considered the gold standard of evidence, their reporting is often suboptimal. Trial registries have the potential to contribute important methodologic information for critical appraisal of study results. METHODS AND FINDINGS: The objective of the study was to evaluate the reporting of key methodologic study characteristics in trial registries. We identified a random sample (n = 265) of actively recruiting RCTs using the World Health Organization International Clinical Trials Registry Platform (ICTRP) search portal in 2008. We assessed the reporting of relevant domains from the Cochrane Collaboration's 'Risk of bias' tool and other key methodological aspects. Our primary outcomes were the proportion of registry records with adequate reporting of random sequence generation, allocation concealment, blinding, and trial outcomes. Two reviewers independently assessed each record. Weighted overall proportions in the ICTRP search portal for adequate reporting of sequence generation, allocation concealment, blinding (including and excluding open label RCT) and primary outcomes were 5.7% (95% CI 3.0-8.4%), 1.4% (0-2.8%), 41% (35-47%), 8.4% (4.1-13%), and 66% (60-72%), respectively. The proportion of adequately reported RCTs was higher for registries that used specific methodological fields for describing methods of randomization and allocation concealment compared to registries that did not. Concerning other key methodological aspects, weighted overall proportions of RCTs with adequately reported items were as follows: eligibility criteria (81%), secondary outcomes (46%), harm (5%) follow-up duration (62%), description of the interventions (53%) and sample size calculation (1%). CONCLUSIONS: Trial registries currently contain limited methodologic information about registered RCTs. In order to permit adequate critical appraisal of trial results reported in journals and registries, trial registries should consider requesting details on key RCT methods to complement journal publications. Full protocols remain the most comprehensive source of methodologic information and should be made publicly available.