Estrés académico y problemas de salud mental en estudiantes de enfermería durante la pandemia de COVID-19

Introducción: La pandemia por COVID-19 ha generado un impacto importante en la formación de profesionales de enfermería, afectando la salud mental en estudiantes debido a las experiencias enfrentadas. Objetivo: Evaluar el nivel de estrés académico en estudiantes de enfermería y su relación con la ansiedad, depresión, insomnio, estrés postraumático y experiencias durante la pandemia de COVID-19. Metodología: Estudio correlacional con 1009 estudiantes matriculados de licenciatura en enfermería que aceptaron participar. Se aplicó encuesta virtual, recolectando datos sociodemográficos y de experiencias durante la pandemia de COVID-19, además de los cuestionarios sobre ansiedad, depresión, insomnio, estrés postraumático y académico, con previa autorización del comité de investigación y ética. El análisis se realizó con Ji cuadrada, Rho de Spearman, y el modelo de regresión logística. Resultados: El 68.1 % presentaron ansiedad, el 64.3 % depresión, el 56.3 % insomnio y el 85.7 % estrés académico. El estrés académico mostró asociación estadística con sexo, periodo académico, diagnóstico en familiar y contacto con persona sospechosa/confirmada de COVID-19. Presentar estrés académico es 3.9 veces mayor con ansiedad moderada, 10.6 veces mayor con depresión moderada, 12.7 veces mayor con insomnio clínico moderado, 1.8 veces mayor con familiar diagnosticado con la enfermedad y 2.6 veces mayor con contacto de casos sospechosos/confirmados de COVID-19. Conclusión: Problemas de salud mental mostraron relación estadística con estrés académico en estudiantes de enfermería durante la pandemia por COVID-19. El profesional de enfermería debe diseñar estrategias educativas y de capacitación para disminuir los niveles de estos problemas, aplicables desde la formación hasta lo laboral

Dosimetric characterization of a microDiamond detector in clinical scanned carbon ion beams

Purpose: To investigate for the first time the dosimetric properties of a new commercial synthetic diamond detector (PTW microDiamond) in high-energy scanned clinical carbon ion beams generated by a synchrotron at the CNAO facility. Methods: The detector response was evaluated in a water phantom with actively scanned carbon ion beams ranging from 115 to 380 MeV/u (30-250 mm Bragg peak depth in water). Homogeneous square fields of 3×3 and 6×6 cm2 were used. Short- and medium-term (2 months) detector response stability, dependence on beam energy as well as ion type (carbon ions and protons), linearity with dose, and directional and dose-rate dependence were investigated. The depth dose curve of a 280 MeV/u carbon ion beam, scanned over a 3×3 cm² area, was measured with the microDiamond detector and compared to that measured using a PTW Advanced Markus ionization chamber, and also simulated using FLUKA Monte Carlo code. The detector response in two spread-out-Bragg-peaks (SOBPs), respectively, centered at 9 and 21 cm depths in water and calculated using the treatment planning system (TPS) used at CNAO, was measured. Results: A negligible drift of detector sensitivity within the experimental session was seen, indicating that no detector preirradiation was needed. Short-term response reproducibility around 1% (1 standard deviation) was found. Only 2% maximum variation of microDiamond sensitivity was observed among all the evaluated proton and carbon ion beam energies. The detector response showed a good linear behavior. Detector sensitivity was found to be dose-rate independent, with a variation below 1.3% in the evaluated dose-rate range. A very good agreement between measured and simulated Bragg curves with both microDiamond and Advanced Markus chamber was found, showing a negligible LET dependence of the tested detector. A depth dose curve was also measured by positioning the microDiamond with its main axis oriented orthogonally to the beam direction. A strong distortion in Bragg peak measurement was observed, confirming manufacturer recommendation on avoiding such configuration. Very good results were obtained for SOBP measurements, with a difference below 1% between measured and TPS-calculated doses. The stability of detector sensitivity in the observation period was within the experimental uncertainty. Conclusions: Dosimetric characterization of a PTW microDiamond detector in high-energy scanned carbon ion beams was performed. The results of the present study showed that this detector is suitable for dosimetry of clinical carbon ion beams, with a negligible LET and dose-rate dependence

Impacto de la radiación de fuga a través del sistema de colimación multihojas en tratamientos de radioterapia de intensidad modulada

Para impartir la dosis de prescripción en tratamientos de radioterapia de intesidad modulada (IMRT), en general, se requerirá un mayor número de unidades monitor (UM) en comparación con impartir la misma dosis en un campo no modulado. Como consecuencia de esto, la dosis recibida por el paciente debido a la radiación de fuga (F) a través del colimador multiho-jas (MLC) incrementará. El objetivo de este trabajo es evaluar el impacto dosimétrico que pequeñas diferen-cias en la radiación de fuga podrían tener en trata-mientos de IMRT

Determination of the Absorbed Dose in Water for Small Photon Beams Using Micro-TLDs of LiF:Mg,Ti (Pilot Audit Proposal)

Background: Small-field dosimetry remains an open challenge globally. Thus, it is crucial to consider adequate reference codes of practice for the performance of dosimetry. Furthermore, as part of good clinical practice, the implementation of new codes of practice implies the development of a dosimetry audit program. In this work, a pilot dosimetric audit protocol is established for measuring the absolute dose in water for small fields using micro-TLDs LiF:Mg,Ti dosimeters. Methods: The dosimeters were irradiated with a 6 MV X-ray beam in a linear accelerator. The TLDs were calibrated between 0.5 and 3 Gy for different field sizes. For audit, the TLDs were irradiated at 2 Gy for different circular field sizes. The proposed protocol consists of five TLD dosimeters forming a cross with a marked radiochromic film to identify the position of the central dosimeter during irradiation. Only the dosimeter measurement in the center of the field is used. Results: It was found that the percentage difference between the measured dose and the prescribed dose (2 Gy) for irradiation in circular fields is less than 3%. Conclusions: A pilot dosimetric audit was carried out using the proposed protocol over a linear accelerator using small circular collimator photon beams

Detector-specific correction factors in radiosurgery beams and their impact on dose distribution calculations

<div><p>Silicon-diode-based detectors are commonly used for the dosimetry of small radiotherapy beams due to their relatively small volumes and high sensitivity to ionizing radiation. Nevertheless, silicon-diode-based detectors tend to over-respond in small fields because of their high density relative to water. For that reason, detector-specific beam correction factors () have been recommended not only to correct the total scatter factors but also to correct the tissue maximum and off-axis ratios. However, the application of to in-depth and off-axis locations has not been studied. The goal of this work is to address the impact of the correction factors on the calculated dose distribution in static non-conventional photon beams (specifically, in stereotactic radiosurgery with circular collimators). To achieve this goal, the total scatter factors, tissue maximum, and off-axis ratios were measured with a stereotactic field diode for 4.0-, 10.0-, and 20.0-mm circular collimators. The irradiation was performed with a Novalis® linear accelerator using a 6-MV photon beam. The detector-specific correction factors were calculated and applied to the experimental dosimetry data for in-depth and off-axis locations. The corrected and uncorrected dosimetry data were used to commission a treatment planning system for radiosurgery planning. Various plans were calculated with simulated lesions using the uncorrected and corrected dosimetry. The resulting dose calculations were compared using the gamma index test with several criteria. The results of this work presented important conclusions for the use of detector-specific beam correction factors ( in a treatment planning system. The use of for total scatter factors has an important impact on monitor unit calculation. On the contrary, the use of for tissue-maximum and off-axis ratios has not an important impact on the dose distribution calculation by the treatment planning system. This conclusion is only valid for the combination of treatment planning system, detector, and correction factors used in this work; however, this technique can be applied to other treatment planning systems, detectors, and correction factors.</p></div

TSF measurements with SFD and calculated with Monte Carlo simulation.

<p>TSF measurements with SFD and calculated with Monte Carlo simulation.</p

Comparison of TMR and OAR between Monte Carlo (MC) simulation of SFD and experimental measurements.

<p>Comparison of TMR and OAR between Monte Carlo (MC) simulation of SFD and experimental measurements.</p

Uncertainty in calculated dose for uncorrected and corrected data sets.

<p>Uncertainty in calculated dose for uncorrected and corrected data sets.</p

Gamma index results for the criteria of 1%/1mm, 1%/3mm, 1%/5mm, 2%/2mm, 2%/3mm, and 3%/3 mm comparing dose distributions between corrected and uncorrected SFD measurements.

<p>Gamma index results for the criteria of 1%/1mm, 1%/3mm, 1%/5mm, 2%/2mm, 2%/3mm, and 3%/3 mm comparing dose distributions between corrected and uncorrected SFD measurements.</p

Comparison dose distributions between corrected and uncorrected dosimetry data sets.

<p>Solid lines are the dose distributions obtained with uncorrected data. Dashed contour lines are dose distributions obtained with data corrected with detector-specific beam correction factors.</p