Implantación de un protocolo de angio-TC coronaria basado en el índice de masa corporal: reducción de dosis, calidad de imagen y rendimiento diagnóstico / Implementing a coronary CT angiography protocol based on the body mass index: radiation dose reduction, image quality, and diagnostic performance

Objetivos: Valorar la relación entre el score de calcio coronario y la elección posterior del kilovoltaje según el criterio del radiólogo en un protocolo estándar (PE) de angio-TC coronaria (aTCC) para descartar enfermedad coronaria. Cuantificar la reducción de la radiación ionizante después de vincular el kilovoltaje al índice de masa corporal en un protocolo de baja dosis (PBD) con reconstrucción iterativa de modelado. Valorar la calidad de imagen y el rendimiento diagnóstico del PBD. Material y método: Las características antropométricas, el score de calcio, los niveles de kilovoltaje y los valores de dosis estimada específica para el tamaño (SSDE) y del producto dosis-longitud fueron comparados entre un grupo de 50 pacientes con PBD reclutados prospectivamente y una cohorte histórica adquirida con el PE. Estos parámetros, el número de segmentos coronarios no valorables sin y con tolerancia de fase, la atenuación y la relación señal-ruido en la aorta ascendente en el PBD fueron correlacionados con una calidad de imagen de nivel excelente según una escala semicuantitativa. El rendimiento diagnóstico por paciente fue calculado usando la revaloración clínica a los 24 meses como el método diagnóstico de referencia, incluyendo las pruebas derivadas. Resultados: En el PE existía una relación entre la presencia de calcio coronario y la elección de kilovoltajes altos (p=0,02), que desaparecía en el PBD (p=0,47). Los valores de SSDE y de DLP en el PBD fueron significativamente inferiores y presentaron menor dispersión que en el PE (9,22 mGy [RIQ 7,84-12,1 mGy] y 97 mGy*cm [RIQ 78-134 mGy*cm] contra 26,5 mGy [RIQ 21,3-36,3 mGy] y 253 mGy*cm [RIQ 216-404 mGy*cm]; p <0,001 para las comparaciones de las medianas y de las dispersiones entre ambos grupos)...(AU)

Objectives: To evaluate the relation between the coronary calcium score and the posterior choice of kilovoltage according to radiologists’ criteria in a standard coronary CT angiography protocol to rule out coronary disease. To quantify the reduction in ionizing radiation after linking kilovoltage to patients’ body mass index in a low-dose protocol with iterative model reconstruction. To evaluate the image quality and diagnostic performance of the low-dose protocol. Material and methods: We compared anthropometric characteristics, calcium score, kilovoltage levels, size-specific dose estimates (SSDE), and the dose-length product (DLP) between a group of 50 patients who were prospectively recruited to undergo coronary CT angiography with a low-dose protocol and a historical group of 50 patients who underwent coronary CT angiography with the standard protocol. We correlated these parameters, the number of coronary segments that could not be evaluated with and without temporal padding, the attenuation, and the signal-to-noise ratio in the ascending aorta in the low-dose protocol with excellent imaging quality according to a semiquantitative scale. To calculate the diagnostic performance per patient, we used 24-month clinical follow-up including all tests as the gold standard. Results: In the standard protocol, the presence of coronary calcium correlated with the selection of high kilovoltage (P=0.02); this correlation was not found in the low-dose protocol (P=0.47). Median values of SSDE and DLP were significantly (P<0.001) lower and less dispersed in the low-dose protocol [9.22 mGy (IQR 7.84-12.1 mGy) vs. 26.5 mGy (IQR 21.3-36.3 mGy) in the standard protocol] and [97mGy*cm (IQR 78-134mGy*cm) vs. 253mGy*cm (IQR 216-404mGy*cm) in the standard protocol], respectively...(AU)

Implementing a coronary CT angiography protocol based on the body mass index: Radiation dose reduction, image quality, and diagnostic performance.

OBJECTIVES: To evaluate the relation between the coronary calcium score and the posterior choice of kilovoltage according to radiologists' criteria in a standard coronary CT angiography protocol to rule out coronary disease. To quantify the reduction in ionizing radiation after linking kilovoltage to patients' body mass index in a low-dose protocol with iterative model reconstruction. To evaluate the image quality and diagnostic performance of the low-dose protocol. MATERIAL AND METHODS: We compared anthropometric characteristics, calcium score, kilovoltage levels, size-specific dose estimates (SSDE), and the dose-length product (DLP) between a group of 50 patients who were prospectively recruited to undergo coronary CT angiography with a low-dose protocol and a historical group of 50 patients who underwent coronary CT angiography with the standard protocol. We correlated these parameters, the number of coronary segments that could not be evaluated with and without temporal padding, the attenuation, and the signal-to-noise ratio in the ascending aorta in the low-dose protocol with excellent imaging quality according to a semiquantitative scale. To calculate the diagnostic performance per patient, we used 24-month clinical follow-up including all tests as the gold standard. RESULTS: In the standard protocol, the presence of coronary calcium correlated with the selection of high kilovoltage (p = 0.02); this correlation was not found in the low-dose protocol (p = 0.47). Median values of SSDE and DLP were significantly (p < 0.001) lower and less dispersed in the low-dose protocol [9.22 mGy (IQR 7.84-12.1 mGy) vs. 26.5 mGy (IQR 21.3-36.3 mGy) in the standard protocol] and [97 mGy cm (IQR 78-134 mGy cm) vs. 253 mGy cm (IQR 216-404 mGy cm) in the standard protocol], respectively. The overall quality of the images obtained with the low-dose protocol was considered good or excellent in 96% of the studies. The parameters associated with image quality in a multivariable model (C statistic = 0.792) were heart rate (estimated coefficient, -0,12 [95% confidence interval: -0.2, -0.04]; p < 0.01) and the SSDE (estimated coefficient, -0,26 [95% confidence interval: -0.51, -0.01]; p < 0.05). The CAD-RADS modifier for a not fully evaluable or diagnostic study was used on two occasions (4%); the final measures for the diagnosis of coronary disease were sensitivity 100%, specificity 94%, and efficacy 94%. CONCLUSIONS: In the standard protocol, the radiologist selects higher kilovoltage for CT angiography studies for patients whose previous calcium score indicates the presence of coronary calcium. In the low-dose protocol, linking kilovoltage with body mass index enables the dose of radiation to be reduced by 65% while obtaining excellent or good image quality in 96% of studies and excellent diagnostic performance.

Occupational radiation and pregnancy: reality or disinformation? A review of the literature and summary of current clinical guidelines.

Exposure to ionizing radiation is a decisive factor in women's choice of entering the field of interventional radiology. This issue explains the low percentage of women in interventional radiology and the high number of women who take leave from work when they are pregnant even though they have no problems with their pregnancy. The current guidelines and legal framework regarding pregnancy and ionizing radiation from different national institutions are not in line with the scientific evidence. They establish recommendations based on disinformation and a need to protect the fetus that has not been scientifically validated. Lack of knowledge and lack of evidence-based information could contribute to gender-based inequality at work. This article reviews the evidence from the articles and clinical guidelines in PubMed, paying special attention to publications from the last five years (2015-2020). Additionally, it reports the results of an online survey of healthcare professionals exposed to radiation in their work.

Development and Evaluation of a Machine Learning Prediction Model for Small-for-Gestational-Age Births in Women Exposed to Radiation before Pregnancy.

Exposure to radiation has been associated with increased risk of delivering small-for-gestational-age (SGA) newborns. There are no tools to predict SGA newborns in pregnant women exposed to radiation before pregnancy. Here, we aimed to develop an array of machine learning (ML) models to predict SGA newborns in women exposed to radiation before pregnancy. Patients' data was obtained from the National Free Preconception Health Examination Project from 2010 to 2012. The data were randomly divided into a training dataset (n = 364) and a testing dataset (n = 91). Eight various ML models were compared for solving the binary classification of SGA prediction, followed by a post hoc explainability based on the SHAP model to identify and interpret the most important features that contribute to the prediction outcome. A total of 455 newborns were included, with the occurrence of 60 SGA births (13.2%). Overall, the model obtained by extreme gradient boosting (XGBoost) achieved the highest area under the receiver-operating-characteristic curve (AUC) in the testing set (0.844, 95% confidence interval (CI): 0.713-0.974). All models showed satisfied AUCs, except for the logistic regression model (AUC: 0.561, 95% CI: 0.355-0.768). After feature selection by recursive feature elimination (RFE), 15 features were included in the final prediction model using the XGBoost algorithm, with an AUC of 0.821 (95% CI: 0.650-0.993). ML algorithms can generate robust models to predict SGA newborns in pregnant women exposed to radiation before pregnancy, which may thus be used as a prediction tool for SGA newborns in high-risk pregnant women.

Radiación ocupacional y embarazo: realidad o desinformación. Revisión en la literatura y actualización según guías clínicas vigentes / Occupational radiation and pregnancy: reality or disinformation? A review of the literature and summary of current clinical guidelines

La exposición a radiaciones ionizantes es un factor condicionante a la hora de elegir radiología vascular intervencionista, lo que justifica el bajo porcentaje de radiólogas dedicadas a ello y el elevado número de bajas en trabajadoras embarazadas de servicios de radiodiagnóstico sin patología gestacional. Las recomendaciones y actual legislación sobre embarazo y manejo de radiaciones ionizantes de las diferentes instituciones nacionales no se ajustan a evidencias científicas, estableciendo medidas de protección basadas en desinformación y una protección injustificada al feto cuya validez no se ha demostrado científicamente. El desconocimiento y falta de información basada en evidencias podría ser una causa de esta disparidad laboral relacionada con el género de los trabajadores.Se realiza una revisión en la base de datos PubMed de los artículos y guías de práctica clínica más relevantes, con especial atención a los publicados en los últimos 5 años (2015-2020), y se describen los resultados de una encuesta online realizada a trabajadores sanitarios expuestos.(AU)

Exposure to ionizing radiation is a decisive factor in women's choice of entering the field of interventional radiology. This issue explains the low percentage of women in interventional radiology and the high number of women who take leave from work when they are pregnant even though they have no problems with their pregnancy. The current guidelines and legal framework regarding pregnancy and ionizing radiation from different national institutions are not in line with the scientific evidence. They establish recommendations based on disinformation and a need to protect the fetus that has not been scientifically validated. Lack of knowledge and lack of evidence-based information could contribute to gender-based inequality at work.This article reviews the evidence from the articles and clinical guidelines in PubMed, paying special attention to publications from the last five years (2015-2020). Additionally, it reports the results of an online survey of healthcare professionals exposed to radiation in their work.(AU)

Referral to radioisotope examination as a source of additional radiation exposure for staff.

BACKGROUND: Every exposure of human to ionizing radiation increases the likelihood of deterministic sequelae. At the same time, it is associated with the risk of stochastic effects. Consequently, this can lead to cancer, mainly of the hematopoietic system. Organs or tissues show a different affinity for gamma radiation. There are many technical and organizational measures which minimize the impact of this radiation on people and especially on the staff of the nuclear medicine laboratory. MATERIALS AND METHODS: The study was based on 208 referrals to the scintigraphic laboratory, which were executed between 26.09.2018 and 13.11.2018 in the Department of Nuclear Medicine of Military Medical Academy Memorial Teaching Hospital of the Medical University of Lodz - Central Veterans` Hospital. Referrals concerned scintigraphic tests of bones, salivary glands, parathyroid glands, myocardial perfusion, somatostatin receptor analogues, renoscintigraphic and lymphoscintigraphic tests. In case of each referral, radiation power was measured at a distance of approx. 10 cm with the use of a calibrated Geiger-Muller detector. Measurements were performed immediately after the end of the last examination each day. Daily measurement of the background radiation dose was also a standard procedure. For calculations, this value was averaged to 0.18µSv/h. Based on the above measurements, a statistical analysis of all data was performed. Obtained data was also analysed after it was ascribed to the person complexing radiopharmaceuticals on a given day. The annual dose for a radiopharmacist is 0.12 mSv, for a technician 0.35 mSv and for a doctor 0.45 mSv. RESULTS: The average radiation dose received every working day by the staff was 11.49 µSv/h. After considering the average distance from the potential source of exposure (50 cm), this power decreased to 0.46µSv/h. In order to calculate the quarterly and annual radiation dose, it was assumed that the employee worked 250 days a year. CONCLUSIONS: Medical records may pose an additional personnel exposure to ionizing radiation. Physicians are the most vulnerable group of employees. The way of radiopharmacists work contributes to the contamination of medical records.

New models for prediction of micronuclei formation in nuclear medicine department workers.

BACKGROUND: Ionizing radiation causes detrimental health effects such as cancer and genetic damage. The study aim was to determine predictors for micronuclei (MN) occurrence and frequency in peripheral blood lymphocytes of health workers professionally exposed to radiation. METHODS: Health workers, age matched, selected for the study on regular check-ups, were divided according to the radiation exposure. The exposed group involved nuclear medicine department employees (54) and the control group comprised workers from other departments (36). Data about workers characteristics and habits, received annual doses (AD), total years of service (TYS) and exposed years of service (EYS) were taken from each subject. Blood samples were taken and micronuclei (MN) number in peripheral blood lymphocytes was calculated using CBMN assay according to standard protocols. RESULTS: Most workers were female, technicians, with mean age of 45.67 years and EYS about 15 years. Health workers exposed to radiation had significantly more MN than controls (p = 0.001). Female gender, older age, higher received annual doses, longer EYS and TYS increased the MN number. Technicians and laboratory workers have higher risk for MN occurrence. Significant predictors of MN formation according to constructed model were workers age, sex, AD and EYS. One EYS year increases MN frequency 1.017 times, while receiving 0.1 mSy raises MN frequency by 26 %. EYS accurately predicts 86.30 % of MN frequencies and AD 64.60 %. CONCLUSIONS: The model, developed for the first time in this study, showed that received annual doses and duration of exposure to radiation can be used for prediction of MN numbers.

Radiosurgery for cerebral arteriovenous malformation during pregnancy: A case report focusing on fetal exposure to radiation.

INTRODUCTION: We present the case of a pregnant woman who underwent linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) and we discuss the fetal exposure to radiation. CLINICAL PRESENTATION: A 20-year-old woman at 18 weeks of gestation presented with right cerebral hemorrhage and underwent urgent evacuation of the hematoma. She recovered well after surgery, but cerebral angiography after the surgery revealed a small deeply seated arteriovenous malformation (AVM) in the right frontal lobe extending to the right basal ganglia. METHODS AND RESULTS: We examined the diffuse AVM and treated it with LINAC-based SRS at 24 weeks of gestation. Before SRS, the fetus was exposed to a radiation dose of 8.26 mGy, which was estimated by conducting an experiment using an adult RANDO phantom, and a radiophotoluminescent (RPL) glass rod dosimeter (GRD) system. The patient underwent Caesarean delivery at 36 weeks of gestation and gave birth to a healthy baby. CONCLUSION: The exposure of fetus to radiation during SRS was exceedingly low. SRS can be used as an alternative treatment to microsurgery for resolving small deeply seated AVMs even in pregnant patients.