Radiaciones ionizantes en trabajadores sanitarios: función tiroidea y niveles de riesgo de exposición laboral / Ionizing radiation in healthcare workers: thyroid function and risk levels of occupational exposure

Introducción: Uno de los sectores donde más se emplean las radiaciones ionizantes es el sanitario. Existen evidencias que sugieren que la exposición a radiaciones ionizantes podría relacionarse con alteraciones en las hormonas tiroideas. Objetivos: Analizar la posible asociación de alteraciones de hormonas tiroideas con la exposición a radiaciones ionizantes en trabajadores sanitarios según la clasificación actual con mayor probabilidad de riesgo (PER A) y menor probabilidad de riesgo (PER B), y la influencia de otros factores asociados, así como, valorar las dosimetrías personales en función de la exposición laboral en distintas zonas de trabajo según el nivel de riesgo. Material y Métodos: Estudio retrospectivo comparativo de valores de TSH, T3 y T4 en trabajadores expuestos (PER A y/o PER B) y un grupo control. Finalmente, se realizó una comparación de valores de dosimetrías personales respecto a zonas de trabajo con distintos niveles de exposición. Resultados: se halla un ligero aumento de los valores de TSH en los trabajadores PER B (2,6 ± 1,4) y PER A (2,7 ± 1,3), frente a no PER (2,4 ± 1,5) sin alcanzar significación estadística. Se ha encontrado diferencia estadísticamente significativa en las dosis quinquenales individuales de los trabajadores en relación a los niveles de exposición laboral con valores de 0,1 ± 0,3 en la zona de exposición baja y de 0,9 ± 1,4 en la zona de exposición media/alta. Conclusiones: Se evidencia la relación entre exposición laboral a radiaciones ionizantes y los valores individuales dosimétricos en trabajadores sanitarios expuestos, por lo que parece conveniente considerar también las zonas de trabajo de cara a las medidas preventivas realizadas en los trabajos con riesgo de exposición a radiaciones ionizantes. (AU)

Introduction: One of the sectors with the highest rates of use of ionizing radiations is the healthcare system. There is some evidence to suggest that exposure to ionizing radiations could be associated with alterations in thyroid hormone levels. Objectives: To analyze a possible association between the levels of thyroid hormones and the occupational exposure to ionizing radiation in healthcare workers according to the current classification of PER A (with more probability of risk of exposure) and PER B (with less probability of risk of exposure), plus the influence of other factors. To analyze the values of personal dosimeters according to the occupational exposure in the different areas of work and level of risk. Material and Methods: Retrospective comparative study of TSH, T3 and T4 in exposed healthcare workers (PER A and PER B) and control group, working from 2014 to 2019. Levels of personal dosimeters were compared in the areas classified according to the level of risk of exposure. Results: No statistically significant relationship was found between the levels of thyroid hormones and the occupational exposure to radiation in PER A, PER B, though higher levels of TSH were found in the exposed groups PER B (2,6 ± 1,4) and PER A (2,7 ± 1,3) compared to TSH levels in the control group (2,4 ± 1,5). There is a statistically significant difference between the individual five-year dose of healthcare workers and the levels of occupational exposure, with values in the areas classified according to the level of exposure with values of 0,1 ± 0,3 in the low exposure area and 0,9 ± 1,4 in the medium/high exposure area. Conclusions: There is a relationship between occupational exposure to ionizing radiations and the individual dosimetric values, thus areas of work should be considered when designing preventive measures in healthcare workers exposed to ionizing radiations. (AU)

Diagnostic value of the stand-alone synthetic image in digital breast tomosynthesis examinations.

OBJECTIVE: To demonstrate the non-inferiority of synthetic image (SI) mammography versus full-field digital mammography (FFDM) in breast tomosynthesis (DBT) examinations. METHODS: An observational, retrospective, single-centre, multireader blinded study was performed, using 2384 images to directly compare SI and FFDM based on Breast Imaging Reporting and Data System (BIRADS) categorisation and visibility of radiological findings. Readers had no access to digital breast tomosynthesis slices. Multiple reader, multiple case (MRMC) receiver operating characteristic (ROC) methodology was used to compare the diagnostic performance of SI and FFDM images. The kappa statistic was used to estimate the inter-reader and intra-reader reliability. RESULTS: The area under the ROC curves (AUC) reveals the non-inferiority of SI versus FFDM based on BIRADS categorisation [difference between AUC (ΔAUC), -0.014] and lesion visibility (ΔAUC, -0.001) but the differences were not statistically significant (p=0.282 for BIRADS; p=0.961 for lesion visibility). On average, 77.4% of malignant lesions were detected with SI versus 76.5% with FFDM. Sensitivity and specificity of SI are superior to FFDM for malignant lesions scored as BIRADS 5 and breasts categorised as BIRADS 1. CONCLUSIONS: SI is not inferior to FFDM when DBT slices are not available during image reading. SI can replace FFDM, reducing the dose by 45%. KEY POINTS: • Stand-alone SI demonstrated performance not inferior for lesion visibility as compared to FFDM. • Stand-alone SI demonstrated performance not inferior for lesion BIRADS categorisation as compared to FFDM. • Synthetic images provide important dose savings in breast tomosynthesis examinations.

Automated Breast Density Computation in Digital Mammography and Digital Breast Tomosynthesis: Influence on Mean Glandular Dose and BIRADS Density Categorization.

RATIONALE AND OBJECTIVES: The study aimed to compare the breast density estimates from two algorithms on full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT) and to analyze the clinical implications. MATERIALS AND METHODS: We selected 561 FFDM and DBT examinations from patients without breast pathologies. Two versions of a commercial software (Quantra 2D and Quantra 3D) calculated the volumetric breast density automatically in FFDM and DBT, respectively. Other parameters such as area breast density and total breast volume were evaluated. We compared the results from both algorithms using the Mann-Whitney U non-parametric test and the Spearman's rank coefficient for data correlation analysis. Mean glandular dose (MGD) was calculated following the methodology proposed by Dance et al. RESULTS: Measurements with both algorithms are well correlated (r ≥ 0.77). However, there are statistically significant differences between the medians (P < 0.05) of most parameters. The volumetric and area breast density median values from FFDM are, respectively, 8% and 77% higher than DBT estimations. Both algorithms classify 35% and 55% of breasts into BIRADS (Breast Imaging-Reporting and Data System) b and c categories, respectively. There are no significant differences between the MGD calculated using the breast density from each algorithm. DBT delivers higher MGD than FFDM, with a lower difference (5%) for breasts in the BIRADS d category. MGD is, on average, 6% higher than values obtained with the breast glandularity proposed by Dance et al. CONCLUSIONS: Breast density measurements from both algorithms lead to equivalent BIRADS classification and MGD values, hence showing no difference in clinical outcomes. The median MGD values of FFDM and DBT examinations are similar for dense breasts (BIRADS d category).

Tomosíntesis de mama: mamografía sintetizada versus mamografía digital. Impacto en la dosis / Breast tomosynthesis: synthesized versus digital mammography. Impact on dose

Objetivo. Comparar la detectabilidad y la visibilidad de las lesiones en la imagen sintetizada y en la mamografía digital. Estimar el ahorro de dosis que supondría utilizar la imagen sintetizada en los exámenes de tomosíntesis. Pacientes y métodos. Siete observadores evaluaron la detectabilidad y la visibilidad de objetos similares a microcalcificaciones sobre las imágenes sintetizadas y mamografías digitales de un maniquí. Cuatro observadores evaluaron retrospectivamente las imágenes de 20 pacientes con lesiones histológicamente corroboradas. Se estimaron retrospectivamente los valores de dosis glandular promedio en una muestra de 50 pacientes. Resultados. La detectabilidad y la visibilidad de las microcalcificaciones sobre el fondo estructural de las imágenes del maniquí fue del 50 y del 100%, respectivamente, superior en la imagen sintetizada. La visibilidad de los hallazgos en las imágenes clínicas fue similar en ambos tipos de imagen, exceptuando las distorsiones, mejor visualizadas en la imagen sintetizada (p = 10−5). Un 16% de hallazgos malignos no se detectaron en las imágenes de mamografía digital y un 7% en las imágenes sintetizadas. La dosis glandular promedio por mama para un examen de 2 proyecciones (mama promedio) fue de 3,2 mGy (mamografía digital), 4,1 mGy (tomosíntesis) y 7,3 mGy (mamografía digital + tomosíntesis). Conclusiones. La detectabilidad y la visibilidad de la imagen sintetizada es equiparable a la mamografía digital. La sustitución de la mamografía digital por la imagen sintetizada supondría un ahorro de dosis del 44% (mama promedio) (AU)

Objective. To compare the detectability and visibility of lesions in synthesized and digital mammography. To estimate the dose saving due to the use of synthesized images in tomosynthesis examinations. Patients and methods. Seven observers scored the detectability and visibility of objects simulating microcalcifications in digital and synthesized images of a phantom. Four observers retrospectively assessed the images from a sample of 20 patients with histologically confirmed lesions. Mean glandular dose values were retrospectively estimated in a sample of 50 patients. Results. The detectability and visibility of microcalcifications in the structural background of phantom images were 50% and 100% higher, respectively, for synthesized images. The visibility of the findings in the clinical images was similar for both types of images, except for distortions, which were better visualized on synthesized images (p = 10−5). Sixteen percent of malignant findings were not detected in digital images and 7% were undetected in synthesized images. The mean glandular dose per breast for a two-view examination (average breast) was 3.2 mGy (digital mammography), 4.1 mGy (tomosynthesis) and 7.3 mGy (digital mammography + tomosynthesis). Conclusions. The detectability and visibility of synthesized images was comparable to that of digital mammography. Replacing digital mammography with synthesized imaging would result in a dose saving of 44% (average breast) (AU)

Impacto del genoma humano en el siglo XXI / Human genome impact in the XXI century

El proyecto de genoma humano ha creado un nuevo campo en la Genética Humana, caracterizado por mejorar los mapas genéticos humanos existentes, por construir mapas físicos de los cromosomas completos y determinar la secuencia completa de subunidades del ADN. Al finalizar este proyecto, le dará a los médicos e investigadores en muchas áreas de la biología, una fuente extraordinaria de información que necesitará un esfuerzo de coordinación en metodología, instrumentación, computación, recolección, análisis, interpretación y manejo de datos. Como resultado de esta expansión y nuevo conocimiento de la genética molecular médica, se iniciará un nuevo enfoque en el diagnóstico, monitoreo, tratamiento y prevención de las enfermedades