¿Es necesario utilizar protectores de gónadas durante la realización de radiografías de tórax en los lactantes? / Is the use of gonad protection protectors necessary during infants chest radiography?

Introducción y objetivos: Comparar las dosis de radiación en las gónadas con y sin protector gonadal y optimizar el uso de estos protectores al realizar radiografías de tórax a lactantes. Materiales y métodos: Se utilizan 2 maniquíes antropomórficos pediátricos, un sistema de rayos X KXO-50SS/DRX-3724HD, y un sistema de radiografía digital CALNEO Smart C12, con y sin protector de gónadas durante la realización de radiografías de tórax. Se coloca un dosímetro cutáneo en tiempo real en el sistema de rayos X y se inserta un dosímetro cutáneo en tiempo real en la cara anterior de la glándula mamaria, en la cara anterior y posterior de la pelvis verdadera, y en los ovarios y testículos. El sistema de rayos X se irradia 15 veces con maniquíes, con y sin el protector de gónadas. Se comparan los valores de las dosis de entrada del paciente medidos por el dosímetro cutáneo en tiempo real para cada maniquí, con y sin el protector de gónadas. Resultados: Los valores medios de las dosis a la entrada del paciente medidos para la cara anterior a nivel de la pelvis verdadera, con y sin el protector, son 10,00 y 5,00μGy en el recién nacido, y 10,00 y 0,00μGy al año, respectivamente. Los valores medios de las dosis a la entrada del paciente medidos para la cara posterior a nivel de la pelvis verdadera con y sin el protector son de 0,00 y 0,00μGy tanto en el recién nacido como al año, respectivamente. Las dosis a la entrada del paciente medidas no se pueden detectar en los ovarios y los testículos ni con el protector ni sin él. No se observan diferencias significativas en los valores de las dosis a la entrada del paciente medidas en la cara anterior y posterior de la pelvis, los ovarios y los testículos en el recién nacido y al año, con y sin el protector (p>0,05).(AU)

Introduction and objectives: To compare gonad doses with and without a gonad protector and to optimize the use of gonadal protectors in infants thorax radiography. Materials and methods: Two pediatric anthropomorphic phantoms are used: an X-ray system for KXO-50SS/DRX-3724HD, and a digital radiography system for CALNEO Smart C12, with and without a gonad protector during infants thorax radiography. A real time skin dosimeter is placed on the X-ray system, and a real time skin dosimeter is inserted on the front side of the mammary gland, the front and back sides of the true pelvis level, and on the ovaries and testes. The X-ray system is irradiated 15 times using phantoms with and without a gonad protector. The measured entrance patient doses values of for the real time skin dosimeter are compared for each phantom, with and without the gonad protector. Results: The medium of measured entrance patient doses values for front side dose of the true pelvis level with and without the protector are 10.00 and 5.00μGy at newborn, and 10.00 and 0.00μGy at one year, respectively. The medium of measured entrance patient doses values for the back side dose of the true pelvis level with and without the protector are 0.00 and 0.00μGy at both newborn one year, respectively. The measured entrance patient doses cannot be detected in the ovaries and testes with or without the protector. No significant differences are observed in the measured entrance patient doses values for the front and back side doses of the pelvis, ovaries, and testes at newborn and one year, with and without the protector (p>0.05). Conclusions: No significant difference was observed in gonad dose measurements with and without the gonad protector during infants chest radiography. We believe that gonadal protector wearing is not necessary.(AU)

Impact of breath hold on regional nodal irradiation and heart volume in field in left breast cancer adjuvant irradiation

Purpose Compared to the free-breathing technique, adjuvant left breast irradiation after breast-conserving surgery or mastectomy using the breath-hold method significantly reduces the heart mean dose, Left anterior descending artery, and ipsilateral lung doses. Movement with deep inspiration may also reduce heart volume in the field and regional node doses. Materials and methods Pre-radiotherapy planning CT was performed in the free-breathing, and breath-hold techniques using RPM, demographic information, clinicopathological data, heart volume in the field, heart mean dose, LAD mean dose, and regional nodal doses were calculated in both free breathing and DIBH. Fifty patients with left breast cancer receiving left breast adjuvant radiation were enrolled. Results There was no significant difference in axillary LN coverage between the two techniques, except for SCL maximum dose, Axilla I node maximum dose, and Axilla II minimum dose in favor of the breath hold technique. The mean age was 47.54 years, 78% had GII IDC, 66% had positive LVSI results, and 74% of patients had T2. The breath hold strategy resulted in considerably decreased mean heart dose (p = 0.000), LAD dose (p = 0.000), ipsilateral lung mean dose (p = 0.012), and heart volume if the field (p = 0.013). The mean cardiac dosage and the dose of the LAD were significantly correlated (p = 0.000, R = 0.673). Heart volume in the field and heart mean dosage was not significantly correlated (p = 0.285, r = − 0.108). Conclusion When compared to free breathing scans, DIBH procedures result in considerably reduced dosage to the OAR and no appreciable changes in dose exposure to regional lymph node stations in patients with left-sided breast cancer (AU)

Construcción y validación de un fantoma torácico pediátrico asequible para optimizar la dosis / Low-cost chest paediatric phantom for dose optimisation: construction and validation

Introducción y objetivosPara llevar a cabo estudios de optimización de dosis, el fantoma de imagenología debe ser adecuado para evaluar la calidad de la imagen. El coste de los fantomas de gama alta suele ser prohibitivo, por lo que es necesario hallar un método de construcción asequible que emplee sustitutos tisulares que sean razonablemente fáciles de obtener.Materiales y métodosSe realizaron cálculos teóricos de las características radiológicas de cada uno de los pulmones, el hueso cortical y los tejidos blandos con el fin de elegir el sustituto adecuado; para ello, se eligieron el corcho, el cloruro de polivinilo (PVC) y el agua, respectivamente. La validación consistió, en primer lugar, en la medición de las unidades Hounsfield (UH) de tomografía computarizada (TC) de los tejidos de un paciente real y su posterior comparación con las anatomías correspondientes en el fantoma construido. En segundo lugar, se obtuvieron los valores de relación señal/ruido (S/R) y de relación contraste/ruido (C/R) para evaluar la calidad de las imágenes generadas a partir del fantoma construido y comparar sus tendencias con un fantoma válido utilizando diferentes parámetros de exposición (valores pico de kilovoltaje [kVp] y miliamperios por segundo [mAs]).ResultadosPartiendo de los cálculos teóricos, las diferencias porcentuales exhibieron una precisión elevada en los sustitutos tisulares al simular los tejidos de un paciente real; con PVC fue de ≥ 5,78%, con corcho ≥ 4,46% y con agua ≥ 5%. La diferencia porcentual (UH de TC) entre el pulmón y el hueso cortical y sus sustitutos tisulares equivalentes fue de 10,44% y de 0,53 a 3,17%, respectivamente. Se encontraron fuertes correlaciones positivas para la S/R al variar tanto los valores de kVp (0,79) como de mAs (0,65). Por el contrario, se halló que la fuerza de correlación de los valores de la C/R era moderada al cambiar los valores de kVp (0,58) y mAs (0,53).(AU)

Introduction and ObjectivesIn order to perform chest dose optimisation studies, the imaging phantom should be adequate for image quality evaluation. Since high-end phantoms are cost prohibitive, there is a need for a low-cost construction method with fairly available tissue substitutes.Materials and MethodsTheoretical calculations of radiological characteristics were performed for each of lung, cortical bone and soft tissues in order to choose appropriate substitute, then, cork, P.V.C. (Polyvinyl Chloride) and water were chosen, respectively. Validation included, firstly, measuring CT Hounsfield Units (HU) of a real patient's tissues then compared against their corresponding anatomies in the constructed phantom. Secondly, Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values were acquired in this study to evaluate the quality of images generated from the constructed phantom, then, compare their trends with a valid phantom under different exposure parameters (kVp and mAs).ResultsFrom theoretical calculations, the percentage differences showed high accuracy of tissue substitutes when simulating real patient tissues; P.V.C. was ≥ 5.78%, cork was ≥ 4.46% and water ≥ 5%. The percentage difference (CT HU) between lung and cortical bone and their equivalent tissue substitutes were 10.44% and 0.53%-3.17%, respectively. Strong positive correlations were found for SNR when changing both kVp (0.79) and mAs (0.65). While the correlation strength of CNR values were found to be moderate when changing both kVp (0.58) and mAs (0.53).ConclusionsOur low-cost phantom approved through CT HU that their materials replicate the radiological characteristics of real one-year-old child while SNR and SNR correlations confirmed its applicability in imaging and optimisation studies.(AU)

Real Decreto 601/2019 sobre justificación y optimización: aspectos prácticos / Royal Decree 601/2019 on justification and optimization: Practical aspects

El Real Decreto 601/2019 de 18 de octubre es fruto de la transposición parcial al ordenamiento jurídico español de la Directiva EURATOM 59/2013. Este Real Decreto recoge los mandatos de la Directiva relacionados con la necesidad de justificar y optimizar la exposición médica, incluida la de personas asintomáticas, la propuesta de requisitos más estrictos en cuanto a la información que debe proporcionarse al paciente, el registro y la notificación de las dosis de los procedimientos médico-radiológicos, el uso de niveles de referencia para diagnóstico y la disponibilidad de dispositivos indicadores de dosis. El artículo revisa los aspectos más relevantes y novedades relacionadas con los principios de justificación, optimización, control de dosis y las obligaciones derivadas del derecho a la información y el consentimiento. El Real Decreto considera fundamental que exista un alto nivel de competencia, y una nueva enumeración de responsabilidades y funciones de los radiólogos, las cuales se detallan y analizan.(AU)

The Royal Decree 601/2019 of 18th october is the result of the partial transposition into the Spanish legal system of the EURATOM Directive 59/2013. This Royal Decree includes the mandates of the Directive related to the need to justify and optimize medical exposure, including that of asymptomatic people, proposal of stricter requirements regarding the information that must be provided to the patient, registration and notification of the doses of medical-radiological procedures, use of reference levels for diagnosis and the availability of dose-indicating devices. The article reviews the most relevant aspects and novelties related to the principles of justification, optimization, dose control and the obligations derived from the right to information and consent. This Royal Decree considers essential for radiologists to develop a high level of competence and a new list of responsibilities and functions, which are detailed and analysed in this article.(AU)

Machine learning-based automated planning for hippocampal avoidance prophylactic cranial irradiation

Purpose Design and evaluate a knowledge-based model using commercially available artificial intelligence tools for automated treatment planning to efficiently generate clinically acceptable hippocampal avoidance prophylactic cranial irradiation (HA-PCI) plans in patients with small-cell lung cancer. Materials and methods Data from 44 patients with different grades of head flexion (range 45°) were used as the training datasets. A Rapid Plan knowledge-based planning (KB) routine was applied for a prescription of 25 Gy in 10 fractions using two volumetric modulated arc therapy (VMAT) arcs. The 9 plans used to validate the initial model were added to generate a second version of the RP model (Hippo-MARv2). Automated plans (AP) were compared with manual plans (MP) according to the dose-volume objectives of the PREMER trial. Optimization time and model quality were assessed using 10 patients who were not included in the first 44 datasets. Results A 55% reduction in average optimization time was observed for AP compared to MP. (15 vs 33 min; p = 0.001).Statistically significant differences in favor of AP were found for D98% (22.6 vs 20.9 Gy), Homogeneity Index (17.6 vs 23.0) and Hippocampus D mean (11.0 vs 11.7 Gy). The AP met the proposed objectives without significant deviations, while in the case of the MP, significant deviations from the proposed target values were found in 2 cases. Conclusion The KB model allows automated planning for HA-PCI. Automation of radiotherapy planning improves efficiency, safety, and quality and could facilitate access to new techniques (AU)

Tomografía computarizada cerebral solicitada desde Urgencias: la realidad / Brain CT requests from emergency department: reality

Objetivos: Evaluar los motivos más frecuentes por los que se solicitan estudios de imagen craneales desde el Servicio de Urgencias y calcular la prevalencia de la patología aguda urgente en este grupo de población. Material y métodos: Se recogieron las tomografías computarizadas (TC) cerebrales solicitadas por el Servicio de Urgencias en los meses de octubre y noviembre de 2018. Se recogieron los siguientes datos: edad, sexo, motivo de solicitud del estudio, hallazgos encontrados en la prueba de imagen, administración de medios de contraste y motivo, y en caso de que el paciente tuviera estudios de imagen craneales previos, reseñar la existencia de cambios. Se utilizó el programa SPSS para hacer el análisis estadístico. Resultados: Se realizaron 507 TC de cerebro urgentes, 41,4% en hombres y 58,6% en mujeres, con una edad media de 65,4±20 años. El motivo de solicitud más frecuente fue el traumatismo craneal (40,5%), y de ellos únicamente el 15,6% presentó patología intracraneal postraumática aguda. El segundo motivo fue sintomatología neurológica focal (16%), de los cuales el 16% presentó infarto isquémico reciente o hemorragia aguda. En cuanto a los hallazgos, el 43,2% de los estudios fueron informados como normales. El hallazgo más frecuentemente encontrado fue lesiones isquémicas de pequeño vaso, en un 20%. En un 3,9% de todos los pacientes se encontraron lesiones ocupantes de espacio, incluyendo lesiones tanto benignas como malignas. Conclusiones: La mayoría de los estudios cerebrales solicitados desde urgencias no muestran patología que modifique el manejo del paciente. La sobreutilización de la TC cerebral urgente sobrecarga los servicios de radiología y somete a la población a radiación innecesaria.(AU)

Objectives: To evaluate the most common reasons for requesting brain CT studies from the emergency department and to calculate the prevalence of urgent acute pathology on this population group. Material and methods: We reviewed brain CT studies requested from the emergency department during October and November 2018. We recorded the following variables: age, sex, reason for requesting the study, CT findings, use of contrast agents and reasons for using them, and, in patients who had undergone previous head CT studies, whether the findings had changed. SPSS was used for statistical analyses. Results: A total of 507 urgent brain CT studies were done (41.4% in men, 58.6% in women; mean age, 65.4±20 years). The most common reason for requesting the study was head trauma (40.5%); only 15.6% of these studies showed acute posttraumatic intracranial lesions. The second most common reason was focal neurologic symptoms (16%); only 16% of these studies showed recent ischemic infarcts or acute bleeding. No pathological findings were reported in 43.2% of the studies. The most common abnormal finding was small vessel disease (20%). Space-occupying lesions (both benign and malignant) were found in 3.9% of all patients. Conclusions: Most brain CT studies requested from the emergency department showed no findings that would modify the management of the patient. Overuse of urgent brain CT increases the radiology department's workload and exposes patients to radiation unnecessarily.(AU)

Urologic, lymphedema, pelvic pain and gastrointestinal symptoms increase after radiotherapy in patients with primary uterine tumors: a prospective longitudinal Swedish cohort study

Purpose Radiotherapy (RT) causes an inflammatory reaction of the tissue which leads to fibrosis and reduced functioning of the pelvic organs. Few studies have shown significant relationships between side effects and RT in uterine tumors. Here, the urological, lymphedema, pelvic pain and gastrointestinal (GI) symptoms were studied before and after RT in patients with primary uterine tumors using the EORTC QLQ-EN24, specifically designed for uterine cancer patients. Methods This prospective cohort study comprised patients with primary uterine tumors who received pelvic radiotherapy (RT). A total of 43 patients were included from May 2014 to February 2019. Patients completed the questionnaires for global health status and functioning before the start of RT and at 3 and 12 months after RT. Results We found a significant worsening of the urological symptoms 3 months after RT which persisted up to 12 months after RT compared to baseline values prior to start of RT (p = 0.007). An exacerbation of the urinary symptoms was seen in patients with vaginal brachytherapy/boost compared to patients with pelvic RT at 12 months after RT (p = 0.053). The severity of lymphedema symptoms increased from RT start to 12 months after RT (p = 0.019) and the pelvic pain were higher at 3 months after RT compared to before RT (p = 0.004). Also, the level of GI symptoms was significantly higher 12 months after RT compared to the RT start (p < 0.001). Conclusions The urologic, lymphedema, pelvic pain and GI symptoms all increase after RT (AU)

SEOR SBRT-SG survey on SRS/SBRT dose prescription criteria in Spain

Aim Stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) are essential tools in radiation oncology. In Spain, the use of these techniques continues to grow as older linear accelerators (linacs) are replaced with modern equipment. However, little is known about inter-centre variability in prescription and dose heterogeneity limits. Consequently, the SBRT-Spanish Task Group (SBRT-SG) of the Spanish Society of Radiation Oncology (SEOR) has undertaken an initiative to assess prescription and homogeneity in SRS/SBRT treatment. In the present study, we surveyed radiation oncology (RO) departments to obtain a realistic overview of prescription methods used for SBRT and SRS treatment in Spain. Methods A brief survey was developed and sent to 34 RO departments in Spain, mostly those who are members of the SEOR SBRT-SG. The survey contained seven questions about the specific prescription mode, dose distribution heterogeneity limits, prescription strategies according to SRS/SBRT type, and the use of IMRT–VMAT (Intensity Modulated Radiation Therapy–Volumetric Modulated Arc Therapy). Results Responses were received from 29 centres. Most centres (59%) used the prescription criteria D95% ≥ 100%. Accepted dose heterogeneity was wide, ranging from 107 to 200%. Most centres used IMRT–VMAT (93%). Conclusions This survey about SRS/SBRT prescription and dose heterogeneity has evidenced substantial inter-centre variability in prescription criteria, particularly for intended and accepted dose heterogeneity. These differences could potentially influence the mean planning target volume dose and its correlation with treatment outcomes. The findings presented here will be used by the SEOR SBRT-SG to develop recommendations for SRS/SBRT dose prescription and heterogeneity (AU)

Oligo metastatic renal cell carcinoma: stereotactic body radiation therapy, if, when and how?

Background and purpose Renal cell carcinoma (RCC) has traditionally been considered radioresistant with a limited role for conventional fractionation as a local approach. Nevertheless, since the appearance of stereotactic body radiation therapy (SBRT), radiotherapy (RT) has been increasingly employed in the management of metastatic RCC (mRCC). The aim of this study was to evaluate the role of SBRT for synchronous and metachronous oligo metastatic RCC patients in terms of local control, delay of systemic treatment, overall survival and toxicity. Patients and methods A Monocentric single institution retrospective data collection was performed. Inclusion criteria were: (1) oligo-recurrent or oligo-progressive disease (less than 5 metastases) in mRCC patients after radical/partial nephrectomy or during systemic therapy, (2) metastasectomy or other metastasis-directed, rather than SBRT not feasible, (3) any contraindication to receive systemic therapy (such as comorbidities), (4) all the histologies were included, (5) available signed informed consent form for treatment. Tumor response and toxicity were evaluated using the response evaluation criteria in solid tumors and the Common Terminology Criteria for Adverse Events version 4.03, respectively. Progression-free survival in-field and out-field (in-field and out-field PFS) and overall survival (OS) were calculated via the Kaplan–Meier method. The drug treatment-free interval was calculated from the start of SBRT to the beginning of any systemic therapy. Results From 2010 to December 2018, 61 patients with extracranial and intracranial metastatic RCC underwent SBRT on 83 lesions. Intracranial and extracranial lesions were included. Forty-five (74%) patients were treated for a solitary metastatic lesion. Median RT dose was 25 Gy (range 10–52) in 5–10 fractions. With a median follow-up of 2.3 years (range 0–7.15), 1-year in-field PFS was 70%, 2-year in-field PFS was 55% (AU)

Acute and intermediate toxicity of 3-week radiotherapy with simultaneous integrated boost using TomoDirect: prospective series of 287 early breast cancer patients

Aims To report toxicity of a hypofractionated scheme of whole-breast (WB) intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) to the tumor bed (TB) using Tomotherapy® with Direct modality. Methods Patients with early breast cancer, undergoing radiotherapy (RT) in 15 daily fractions to WB (prescription dose 40.05 Gy) and SIB to the TB (48 Gy), between 2013 and 2017, was analyzed. Primary endpoint was acute and intermediate toxicity assessed at the end and within 6 months from RT, according to Radiation Therapy Oncology Group (RTOG) scale. Secondary endpoints included early chronic toxicity at 12-months follow-up, using the Late Effects Normal Tissue Task Subjective, Objective, Management, and Analytic (LENT-SOMA) scale, and cosmesis using Harvard criteria. Results The study population was of 287 patients. Acute and intermediate toxicity was collected among 183 patients with data available at the end of RT and within 6 months, 85 (46%) experienced G2 toxicity and 84 (46%) G1 toxicity, while 14 (8%) did not report toxicity at any time. A significant reduction of any grade toxicity was observed between the two time points, with the majority of patients reporting no clinically relevant toxicity at 6 months. At univariate analysis, age < 40 years, breast volume > 1000 cm3 and Dmax ≤ 115% of prescription dose were predictive factors of clinically relevant acute toxicity (G ≥ 2) at any time. At multivariable analysis, only age and breast volume were confirmed as predictive factors, with Relative Risks (95% Confidence Intervals): 2.02 (1.13–3.63) and 1.84 (1.26–2.67), respectively. At 12-month follow-up, 113 patients had complete information on any toxicity with 53% of toxicity G < 2, while cosmetic evaluation, available for 102 patients, reported a good–excellent result for 86% of patients (AU)

Estudio de la dosis eritematosa mínima en una serie de urticaria solar / Study of Minimal Erythema Dose in a Series of Solar Urticaria

Antecedentes La dosis eritematosa mínima (DEM) reducida es una reacción anormal a la luz según el fototipo de piel y que se determina mediante fototest. La DEM es reducida o anormal en algunas fotodermatosis. Sin embargo, no hemos encontrado información sobre la DEM reducida en pacientes con urticaria solar (US), enfermedad que cursa con urticaria tras la exposición al sol. Objetivo Determinar la DEM en una serie de pacientes con US. Métodos Llevamos a cabo un estudio prospectivo de casos de US diagnosticados en nuestro departamento entre enero de 2007 y diciembre de 2017, a través de anamnesis o por provocación mediante exposición a la luz solar natural o a fuentes de luz artificial. De acuerdo con el protocolo del Grupo Español de Fotobiología, a las 24 horas se llevó a cabo la lectura del fototest en todos los pacientes. Se recopilaron las variables relativas al paciente (edad, sexo, fototipo), enfermedad (tiempo de evolución, espectro de activación) y otras relacionadas con la posible DEM reducida (autoanticuerpos, medicación fototóxica). Resultados Se estudiaron 25 pacientes, de los cuales, seis (24%) presentaron una DEM anormal, el 83% de ellos eran hombres, y el 50% mostraba el espectro de acción en el rango de la radiación UVB. Conclusión Hasta en una cuarta parte de los pacientes con US se puede observar la DEM anormal. Esta circunstancia podría tener implicaciones en la selección de los pacientes y en los protocolos para el tratamiento con fototerapia (AU)

Background Reduced minimal erythema dose (MED) is an abnormal erythematous reaction to light according to the skin phototype, which is determined by phototest. MED is reduced or abnormal in some photodermatoses. However, we have not found information about reduced MED in patients with solar urticarial (SU), a condition which causes hives after sun exposure. Objective To determine MED in a series of patients with SU. Methods We conducted a prospective study of SU cases diagnosed in our department between January 2007 and December 2017, either by anamnesis, provocation with natural sunlight or provocation with artificial light sources. In all patients, a phototest with reading at 24 h was performed according to the protocol of the Spanish Group of Photobiology. Variables related to the patient (age, sex, phototype), disease (time of evolution, action spectrum) and others related to possible reduced MED (autoantibodies, phototoxic medication) were collected. Results Twenty-five patients were studied. Six patients (24%) had abnormal MED. Eighty-three percent of patients with abnormal MED were men, and 50% had action spectrum in UVB. Conclusion Abnormal MED can be seen in up to a fourth of the patients with SU. This could have implications in the selection of patients and protocols for treatment with phototherapy (AU)

Comparison of clinical diagnostic value of spiral CT with different dose in patients with early-stage peripheral lung cancer

Purpose To compare the clinical diagnostic value of spiral CT scan with different dose in patients with early-stage peripheral lung cancer. Methods A total of 163 cases of patients with early-stage peripheral lung cancer who came to People’s Hospital of Rizhao for treatment from June 2014 to January 2017 were retrospectively analyzed. A total of 78 cases of patients who received low-dose CT scanning were the low-dose group, another 84 cases of patients who received routine dose CT scanning were the routine dose group. Multislice helical CT (MSCT) scanning was performed in both groups, with tube voltage of 120 kV. Tube current was 25 m A in the low-dose group and 250 m A in the routine dose group. In addition, a total of 80 patients with lobar pneumonia were added as the control group of diagnostic sensitivity, specificity and accuracy. Pathological diagnosis was taken as the gold standard to compare the diagnostic sensitivity, specificity and accuracy of the two groups. Results The image quality, nodules and signs of the two groups were compared, and the results of radiation dose of the two groups were compared. The diagnostic sensitivity, specificity and accuracy of the low-dose group were 82.05%, 87.50% and 84.81%, respectively. The diagnostic sensitivity, specificity and accuracy of the routine dose group were 85.71%, 86.25% and 85.97%, respectively. The diagnostic value of the two groups was not statistically significant (p > 0.05). However, the radiation dose in the low-dose group was significantly lower than that in the routine group. Conclusion Low-dose MSCT scanning can meet the clinical requirements for imaging diagnosis of peripheral lung cancer, and can reduce the radiation dose of patients (AU)

miR-144-3p increases radiosensibility of gastric cancer cells by targeting inhibition of ZEB1

Purpose This study set out to probe into the effect and mechanism of miR-144-3p on radiosensitivity of gastric cancer (GC) cells. Methods Cancer tissue and paracancerous tissue of GC patients admitted to our hospital were collected, their miR-144-3p expression was tested, GC cells were transfected, and survival and biological behavior of those cells under radiation were detected. Results After detection, miR-144-3p expression was down-regulated in GC tissue, while ZEB1 was up-regulated. There was no remarkable difference in the survival fraction of cells in each group before receiving radiation, but that of tumor cells decreased obviously (p < 0.05) after radiation exposure. Survival fraction of cells overexpressing miR-144-3p or silencing ZEB1 decreased more obviously, while the inhibition of miR-144-3p or overexpressing ZEB1 was weaker. Biological behavior of cells under 6 Gy radiation was detected. It was found that miR-144-3p overexpression or silencing ZEB1 dramatically inhibited the proliferation activity of GC cells under 6 Gy radiation, increased the levels of pro-apoptotic Bax and caspase-3 proteins (p < 0.05) and decreased the anti-apoptotic protein Bcl-2 level (p < 0.05), resulting in an increase in the apoptosis rate of cells. miR-144-3p was confirmed to be ZEB1 targeting site by dual luciferase report. Moreover, rescue experiments prove that it can increase the radiosensitivity of GC cells by regulating ZEB1 expression. Conclusion miR-144-3p expression was down-regulated in GC, and it can increase the radiosensitivity of those cells by inhibiting ZEB1 expression (AU)

Decrease in treatment intensity predicts worse outcome in patients with locally advanced head and neck squamous cell carcinoma undergoing radiochemotherapy

Purpose Radiochemotherapy (RCT) is an effective standard therapy for locally advanced head and neck squamous cell carcinoma (LA-HNSCC). Nonetheless, toxicity is common, with patients often requiring dose modifications. Methods To investigate associations of RCT toxicities according to CTCAE version 5.0 and subsequent therapy modifications with short- and long-term treatment outcomes, we studied all 193 patients with HNSCC who received RCT (70 Gy + platinum agent) at an academic center between 03/2010 and 04/2018. Results During RCT, 77 (41%, 95% CI 34–49) patients developed at least one ≥ grade 3 toxicity, including seven grade 4 and 3 fatal grade 5 toxicities. The most frequent any-grade toxicities were xerostomia (n = 187), stomatitis (n = 181), dermatitis (n = 174), and leucopenia (n = 98). Eleven patients (6%) had their radiotherapy schedule modified (mean radiotherapy dose reduction = 12 Gy), and 120 patients (64%) had chemotherapy modifications (permanent discontinuation: n = 67, pause: n = 34, dose reduction: n = 7, change to other chemotherapy: n = 10). Objective response rates to RCT were 55% and 88% in patients with and without radiotherapy modifications (p = 0.003), and 84% and 88% in patients with and without chemotherapy modifications (p = 0.468), respectively. Five-year progression-free survival estimates were 20% and 50% in patients with and without radiotherapy modifications (p = < 0.001), and 53% and 40% in patients with and without chemotherapy modifications (p = 0.88), respectively. Conclusions Reductions of radiotherapy dose were associated with impaired long-term outcomes, whereas reductions in chemotherapy intensity were not. This suggests that toxicities during RCT should be primarily managed by modifying chemotherapy rather than radiotherapy (AU)

Hypofractionated whole breast irradiation after IORT treatment: evaluation of acute toxicity and cosmesis

Introduction Hypofractionated whole breast irradiation (HWBI) is the current standard of treatment after breast conservative surgery (BCS). Intraoperative radiotherapy (IORT) must be associated to WBI in patients showing high-risk factors of local recurrence in the definitive pathology report. The aim of this trial was to evaluate, for the first time, the acute toxicity and cosmesis of HWBI after photon-IORT. Materials and methods Twenty-six luminal breast cancer patients treated by BCS and IORT(20 Gy) were included between February and December 2019, in this prospective trial, of adjuvant HWBI (40.5 Gy/2.67 Gy/15 fractions). Acute toxicity (CTCAEv5.0) and cosmesis (Harvard scale), were assessed 3 months after treatment. Results All patients completed their treatment without interruptions. All cases were evaluable 3 months after treatment showing no toxicity ≥ G3 and excellent/good cosmesis assessment in 88% of the patients. Conclusion HWBI seems to have similar acute toxicity and cosmesis results than conventionally fractionated WBI in combination to photon-IORT after BCS (AU)

El uso de rayos X en odontología y la importancia de la justificación de exámenes radiográficos / Use of X rays in dentistry and the importance of justification of radiographic examinations

INTRODUCCIÓN: Los exámenes radiográficos odontológicos usan radiaciones ionizantes, las que pueden producir efectos adversos en la salud de pacientes y trabajadores ocupacionalmente expuestos a radiaciones. La protección radiológica busca que la justificación de la exposición a radiación ionizante sea adecuada, y produzca al paciente mayor beneficio que riesgo. El objetivo del presente artículo es revisar los efectos adversos de las radiaciones ionizantes en el ser humano, analizar el principio de justificación y entregar recomendaciones para su aplicación en la práctica diaria odontológica, presentando guías clínicas actuales. REVISIÓN: Para cumplir con el principio de justificación, la elección de cada examen radiográfico debe realizarse responsablemente, basándose en las necesidades individuales de cada paciente. Este proceso debe realizarse conjuntamente entre clínico y radiólogo maxilofacial. A pesar de que existen numerosas guías para distintas especialidades odontológicas, desarrolladas por instituciones de diversas partes del mundo, son pocas las guías basadas en evidencia. Las guías aportan recomendaciones, con distintos niveles de evidencia, para el uso de exámenes radiográficos, permitiendo al clínico seleccionar el examen adecuado para cada paciente, contribuyendo a la disminución de exposiciones innecesarias. CONCLUSIONES: La comunicación entre clínico y radiólogo maxilofacial es fundamental para lograr el proceso de justificación, y por lo tanto, una reducción en las dosis de radiación a los pacientes. Además, es necesario el uso de guías clínicas para correcta selección del examen radiográfico. Se requiere más investigación que justifique el uso de nuevas tecnologías imagenológicas en indicaciones específicas y permitan elaborar guías clínicas basadas en evidencia

INTRODUCTION: Dental radiographic examinations use ionizing radiation, which can have adverse health effects in patients and workers occupationally exposed to radiation. Radiological protection seeks to ensure that justification for exposure to ionizing radiation is adequate, so that the patient has a greater benefit than risk. The aim of this article is to review the adverse effects of radiation on humans, to analyze the principle of justification and to provide recommendations for its application in daily dental practice, presenting current clinical guidelines. REVIEW: In order to comply with the principle of justification, the choice of each radiographic examination must be made in a responsible manner, based on the individual needs of each patient. This process should be performed jointly between the clinician and the maxillofacial radiologist. Although there are numerous guidelines for different dental specialties, developed by institutions from different parts of the world, few of them are evidence-based guidelines. Guidelines provide recommendations, with different levels of evidence, for the use of radiographic examination, allowing the clinician to select the appropriate exam for each patient, contributing to the reduction of unnecessary exposures. CONCLUSIONS: Communication between clinician and maxillofacial radiologist is essential to achieve the justification process, and therefore a reduction in radiation doses to patients. In addition, the use of clinical guidelines is necessary for a correct choice of the radiographic examination. More research is needed to justify the use of new imaging technologies in specific indications, to develop clinical evidence-based guidelines

Cosméticos radioactivos. La belleza «radiante» / Radioactive Cosmetics and Radiant Beauty

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Leukocyte- and platelet-rich fibrin does not provide any additional benefit for tooth extraction in head and neck cancer patients post-radiotherapy: a randomized clinical trial

BACKGROUND: One of the most important complications of radiotherapy (RT) for head and neck cancer (HNC) is osteoradionecrosis (ORN) of the jaws, arising mainly from tooth extractions. Thus, the present study aimed to evaluate the efficacy of leukocyte- and platelet-rich fibrin (L-PRF) in preventing ORN following tooth extraction in post-irradiated HNC patients, as well as other postoperative complications. MATERIAL AND METHODS: 23 patients previously submitted to conventionally fractionated 3D-conformational RT for HNC underwent atraumatic tooth extractions with perioperative antibiotic therapy. Besides, they were randomly as-signed to receive L-PRF clots to fill and cover the extraction sockets (n = 11, Test Group) or not (n = 12, Control Group). A visual analog scale was used to quantify postoperative pain on the 3rd and 7th days. For ORN diagnosis, patients were clinically assessed for up to 180 days. Other postoperative complications (edema, alveolitis, suture dehiscence, continuous bleeding, and oroantral communication) were also evaluated within this period. RESULTS: No case of ORN or another surgical complication was observed and there were no differences in the postoperative pain scores between the groups on the 3rd and 7th days. CONCLUSIONS: L-PRF did not seem to provide any additional benefits than those achieved by the combination of the surgical and drug protocols used for tooth extractions in the post-irradiated HNC patients

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Estudio prospectivo comparativo de dos métodos de cálculo individual de la actividad de 131I en el tratamiento del hipertiroidismo / A prospective comparative study of two methods of individual calculation of 131I activity in the treatment of hyperthyroidism

OBJETIVO: El radioyodo (131I) constituye una modalidad establecida de tratamiento definitivo del hipertiroidismo. A pesar de la vasta experiencia existente, persisten varios aspectos por clarificar, como qué tipo de dosis emplear, ¿fijas o calculadas? El objetivo del estudio fue determinar si se podría mejorar la eficacia de este tratamiento implementando un método simple de cálculo dosimétrico que incluyera la estimación ecográfica del volumen tiroideo y una medida única de captación de 131I (24h). MÉTODOS: Diseñamos un estudio prospectivo de no inferioridad comparando entre dos modalidades de cálculo de la actividad de radioyodo: el método de dosis «semifijas» (A) y el de dosis «calculadas» (B). El primero consistió en escaladas de actividad (peldaños de 185MBq) teniendo en cuenta: etiología del hipertiroidismo, captación de 131I y objetivo terapéutico. El segundo se basó en el concepto de «compromiso dosimétrico», considerando como únicos factores la captación y el volumen tiroideos, empleando una vida media estándar de 5,5días. La dosis absorbida diana fue 150Gy, aunque tras un análisis preliminar (100 primeros casos) se aumentó a 200Gy en los bocios difusos tóxicos (BDT). RESULTADOS: Se incluyeron 212 pacientes. El métodoB resultó al menos igual de eficaz en cuanto al resultado final y funcional, con tendencia a más éxitos y menos hipotiroidismo. Además, las actividades administradas fueron significativamente menores. CONCLUSIÓN: En la terapia con radioyodo del hipertiroidismo se pudo implementar un método dosimétrico sencillo que proporcionó resultados al menos iguales a los de un método basado en dosis fijas, con actividades administradas inferiores

OBJECTIVE: Radioiodine (131I) is an established modality of definitive treatment of hyperthyroidism. In spite of the vast experience available, there are still several aspects to be clarified, such as whether fixed or calculated doses should be used. The aim of this study was to assess whether efficacy of this treatment could be improved by implementing a simple dosimetric calculation method including ultrasonographic estimation of thyroid volume and a single measurement of 24-hour 131I thyroid uptake. METHODS: A prospective non-inferiority study was designed to compare two procedures to calculate radioiodine activity: the «semi-fixed» dose method (A), and the «calculated» dose method (B). The first consisted of activity escalation (185MBq steps) based on etiology of hyperthyroidism, 131I uptake, and treatment objective. The second method was based on the «dosimetric compromise» concept, considering 24-hour uptake and thyroid volume as the only factors and using a standard half-life of 5.5 days. The target absorbed dose was 150Gy, but after a preliminary analysis (first 100 cases) it was increased to 200Gy in diffuse toxic goiters (DTGs). RESULTS: A total of 212 patients were included. MethodB was at least as effective in terms of final and functional outcome, with a trend to more success and less hypothyroidism. In addition, activities administered were significantly lower. CONCLUSION: In radioiodine therapy of hyperthyroidism, a simple dosimetric method that provided results at least equal to those of a fixed dose-based method, with lower administered activities, could be implemented

El ocaso del modelo lineal sin umbral / The downfall of the linear non-threshold model

El modelo lineal sin umbral (MLSU) es una función dosis-respuesta teórica obtenida de extrapolar los efectos tardíos debidos a la exposición a altas dosis de radiación ionizante al rango de las bajas dosis, pero existen grandes incertidumbres respecto a su validez. La aceptación del MLSU como modelo probabilístico preponderante ha sobrevivido hasta nuestros días y constituye la piedra angular que sostiene las políticas actuales de protección radiológica. En las últimas décadas, los avances en biología molecular y evolutiva, en la inmunología del cáncer, así como los resultados obtenidos de los estudios epidemiológicos y en modelos animales, han puesto en entredicho la fiabilidad del MLSU en favor de otras alternativas, como la teoría hormética. A la vista de las evidencias, se hace necesario un debate entre las sociedades científicas implicadas y los organismos reguladores que aborde una redefinición de las bases de la protección radiológica, cuya importancia sería capital en el ámbito médico

The linear non-threshold model (LNTM) is a theoretical dose-response function as a result of extrapolating the late effects of high-dose exposure to ionizing radiation to the low-dose range, but there is great uncertainty about its validity. The acceptance of LNTM as the dominant probabilistic model have survived to the present day and it is actually the cornerstone of current radiation protection policies. In the last decades, advances in molecular and evolutive biology, cancer immunology, and many epidemiological and animal studies have cast serious doubts about the reliability of the NLTM, as well as suggesting alternative models, like the hormetic theory. Considering the given evidences, a discussion between the involved scientific societies and the regulatory commissions is promtly required in order to to reach a redefiniton of theradiation protection basis, as it would be specially crucial in the medical field