Basis for the ICRP’s updated biokinetic model for systemic astatnie

The ICRP recently updated its biokinetic models for workers in a series of reports called the OIR (Occupational Intakes of Radionuclides) series. A new biokinetic model for astatine, the heaviest member of the halogen family, was adopted in OIR Part 5 (ICRP Publication 151, in press). This paper provides an overview of available biokinetic data for astatine; describes the basis for the ICRP’s updated model for astatine; and tabulates dose coefficients for intravenous injection of each of the two longest lived and most important astatine isotopes, 211At and 210At. Astatine-211 (T1/2 = 7.214 h) is a promising radionuclide for use in targeted α-particle therapy due to several favorable properties including its half-life and the absence of progeny that could deliver significant radiation doses outside the region of α-particle therapy. Astatine-210 (T1/2 = 8.1 h) is an impurity generated in the production of 211At in a cyclotron and represents a potential radiation hazard via its long-lived progeny 210Po (T1/2 = 138 d). Tissue dose coefficients for injected 210At and 211At based on the updated model are shown to differ considerably from values based on the ICRP’s previous model for astatine, particularly for the thyroid, stomach wall, salivary glands, lungs, spleen, and kidneys.

Determinación de los niveles de referencia de dosis (DRL) para diagnóstico de baja y media complejidad en Servicios Especiales de Salud Hospital Universitario de Caldas de Colombia (SES-HUC)

Objetivo: Los niveles de referencia de dosis para diagnóstico (dose reference levels - DRL) son una herramienta útil para optimizar la protección radiológica en exposiciones médicas de diagnóstico. Su determinación es un requisito para obtener la licencia de uso de equipos emisores de radiación ionizante en los servicios de imágenes diagnósticas de Colombia. El objetivo de este trabajo fue establecer los valores de DRL institucionales con diversos equipos emisores de radiación ionizante para los procedimientos de diagnósticos más comunes asociados a áreas anatómicas típicas. Metodología: Este estudio fue realizado en dos equipos de radiología convencional, un equipo de mamografía, un equipo de tomografía computada (TC) y un equipo de fluoroscopia tipo arco en C. La muestra estadística se clasificó de acuerdo con los tipos de estudio, las áreas anatómicas de interés, tamaño y rangos de pesos de pacientes. Los tamaños de la muestra variaron según la técnica diagnóstica, siguiendo recomendaciones del documento técnico “Diagnostic reference levels in medical imaging. ICRP Publication 135”. Los datos de la dosis entregada a cada paciente se obtuvieron registrando el valor de dosis estimado por el equipo de adquisición de imagen. El análisis estadístico se hizo por medio de diagramas de cajas y distribuciones de frecuencias, donde el tercer cuartil se definió como el valor de DRL para cada técnica de adquisición de imagen. Resultados: Los valores obtenidos de DRL para radiografía convencional fueron inferiores a 15 dGy.cm2 para pacientes con pesos entre 50-80 kg, e inferiores a 27 dGy.cm2 para pacientes de más de 80 kg. Para mamografía, los valores de DRL a través de la dosis glandular media fueron inferiores a 2,7 mGy para proyecciones oblicuas con espesores entre 45-94 mm. Los índices de dosis en tomografía computarizada en volumen (CTDIvol) y los valores de producto dosis-longitud (DLP) fueron inferiores a 41,4 mGy y 907 mGy.cm respectivamente, obteniendo los mayores valores en cráneo y los menores en abdomen para pacientes entre50 y 80 kg. En procedimientos con arco en C, los valores obtenidos de DRL fueron iguales a 2,69 Gy.cm2 para colangiopancreatografía retrógrada endoscópica (CPRE), 2,88 Gy.cm2 para histerosalpingografía (HSG) y 9,22 Gy.cm2 para colon por enema. Conclusiones: Los niveles de referencia de dosis en procedimientos diagnósticos obtenidos en este estudio para SES-HUC, han arrojado valores comparables a los publicados por otros autores en análisis similares, aplicando métodos de análisis sugeridos por organismos internacionales.

The role of empathy in ethics of radiological protection

Radiological protection is often considered a matter of scientific and technological facts only, not of value judgements. This perception is now gradually changing, especially with ICRP Publication 138, which addressed the ethical foundation of the system of radiological protection. It identified values which have guided the Commission’s recommendations over the decades, but have not always been made explicit. Four core values are discussed (beneficence/non-maleficence, prudence, justice, dignity) as well as three procedural values (accountability, transparency, inclusivity). The latter are considered critical to the practical implementation of the system of radiological protection. Here we are exploring empathy as a procedural values complementing the three identified in ICRP Publication 138. Empathy can be defined as the “capability (or disposition) to immerse oneself in and to reflect upon the experiences, perspectives and contexts of others”. It is often understood as a skill that one either has or has not, but research has shown it can be taught and therefore can be required as an attitude of those working in health care, education, design, and technology. We suggest it is an essential prerequisite to the assessment and management of any radiological situation and the health problems accruing from it. The concerns of people affected, their needs and wishes need to be taken seriously from the very beginning of any decision-making process. Even if they are considered unfounded and exaggerated, the insights they provide will be valuable for the understanding of the overall situation. Without empathy, our practice of beneficence and non-maleficence as well as solidarity would be oddly limited.

Areas of research to support the system of radiological protection

This document presents the ICRP's updated vision on “Areas of Research to Support the System of Radiological Protection”, which have been previously published in 2017. It aims to complement the research priorities promoted by other relevant international organisations, with the specificity of placing them in the perspective of the evolution of the System of Radiological Protection. This document contributes to the process launched by ICRP to review and revise the System of Radiological Protection that will update the 2007 General Recommendations in ICRP Publication 103.

Performance Testing of Eye Lens Dosemeter and Evaluation of Personal Radiological Exposition at Douera Orthopedic Interventional Service

The radiological monitoring of the eye in the workplace depends on the type of dosemeter used and its performance. The dosimetric performances of Nuclear Research Center of Algiers (CRNA) developed eye lens dosemeter (Larabi-Harfouche et al. Characterization and qualification of a CRNA eye dosimeter. Perspect Sci. 12, 100402 (2019)) are investigated in this work in order to assess its ability to measure the operational quantity Hp(3) in photon fields and to check its compliance with the International Commission on Radiological Protection recommendations for professionally exposed people (ICRP. ICRP statement on tissue reactions/early and late effects of radiation in normal tissues and organs – threshold doses for tissue reactions in a radiation protection context. ICRP Publication 118. Ann. ICRP 41(1/2) (2012)). Some key performance indicators including the relative response of the nonlinearity, coefficient of variation, and photon energy and angular dependence are assessed before the use of this dosemeter for eye lens monitoring of orthopedic staff in the operating room at Douera hospital. The monitoring results of this first pilot study are presented and discussed in view of supporting the recommendations of the International Organization for Standardization 15382: 2015 concerning the monitoring of the dose at lens.