Results of 2023 survey on the use of synthetic computed tomography for magnetic resonance Imaging-only radiotherapy: Current status and future steps.

Background and purpose: The emergence of synthetic CT (sCT) in MR-guided radiotherapy (MRgRT) represents a significant advancement, supporting MR-only workflows and online treatment adaptation. However, the lack of consensus guidelines has led to varied practices. This study reports results from a 2023 ESTRO survey aimed at defining current practices in sCT development and use. Materials and methods: An survey was distributed to ESTRO members, including 98 questions across four sections on sCT algorithm generation and usage. By June 2023, 100 centers participated. The survey revealed diverse clinical experiences and roles, with primary sCT use in the pelvis (60%), brain (15%), abdomen (11%), thorax (8%), and head-and-neck (6%). sCT was mostly used for conventional fractionation treatments (68%), photon SBRT (40%), and palliative cases (28%), with limited use in proton therapy (4%). Results: Conditional GANs and GANs were the most used neural network architectures, operating mainly on 1.5 T and 3 T MRI images. Less than half used paired images for training, and only 20% performed image selection. Key MR image quality parameters included magnetic field homogeneity and spatial integrity. Half of the respondents lacked a dedicated sCT-QA program, and many did not apply sanitychecks before calculation. Selection strategies included age, weight, and metal artifacts. A strong consensus (95%) emerged for vendor neutral guidelines. Conclusion: The survey highlights the need for expert-based, vendor-neutral guidelines to standardize sCT tools, metrics, and clinical protocols, ensuring effective sCT use in MR-guided radiotherapy.

Descripción anatómica de los segmentos óseos que componen el cráneo de la especie Pudu puda / Anatomical description of the bone segments that make up the skull of the Pudu puda species

RESUMEN: El Pudú (Pudu puda), uno de los ciervos más pequeños del mundo y autóctono de Chile, es considerado como vulnerable (VU) en todo el territorio nacional, hay escasa información específica de los sistemas orgánicos que lo componen y cada vez es más común encontrarlos en zonas urbanas. Estas problemáticas hacen despertar la necesidad de fortalecer la investigación y el estudio de esta especie. En consecuencia, en el presente estudio se realizó una descripción anatómica del esqueleto craneal de dos ejemplares de Pudu puda, donde se destacaron sus principales características óseas comparándolas con especies domesticas ya estudiadas (ovino y caprino). Así se logró determinar diferencias entre las especies estudiadas y la necesidad de profundizar el análisis a través de mediciones de las piezas óseas.

SUMMARY: The Pudú (Pudu puda), one of the smallest deer in the world and indigenous to Chile, is considered vulnerable (VU) throughout the national territory, there is little specific information on the organic systems that compose it, and it is becoming more common find them in urban areas. These problems awaken the need to strengthen research and study of this species. Consequently, in the present study an anatomical description of the cranial skeleton of two specimens of Pudú puda was made, where their main bony characteristics were highlighted by comparing them with domestic species already studied (sheep and goats). Thus, it was possible to determine differences between the species studied and the need to deepen the analysis through measurements of the bone pieces.

Erupción exantemática en paciente con mononucleosis infecciosa inducida por aminopenicilina / Aminopenicillin-induced exanthematous eruption in a patient with infectious mononucleosis

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Reply to the comment on 'Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy 125I and 192Ir sources and 60Co cell irradiation'.

A discrepancy between the Monte Carlo derived relative standard deviation [Formula: see text] (microdosimetric spread) and experimental data was reported by Villegas et al (2013 Phys. Med. Biol. 58 6149-62) suggesting wall effects as a plausible explanation. The comment by Lindborg et al (2015 Phys. Med. Biol. 60 8621-4) concludes that this is not a likely explanation. A thorough investigation of the Monte Carlo (MC) transport code used for track simulation revealed a critical bug. The corrected MC version yielded [Formula: see text] values that are now within experimental uncertainty. Other microdosimetric findings are hereby communicated.

Microdosimetric spread for cell-sized targets exposed to 6°Co, ¹9²Ir and ¹²5I sources.

The magnitude of the spread in specific energy deposition per cell may be a confounding factor in dose-response analysis motivating derivation of explicit data for the most common brachytherapy isotopes (125)I and (192)Ir, and for (60)Co radiation frequently used as reference in RBE studies. The aim of this study is to analyse the microdosimetric spread as given by the frequency distribution of specific energy for a range of doses imparted by (125)I, (192)Ir and (60)Co sources. An upgraded version of the Monte Carlo code PENELOPE was used for scoring energy deposition distributions in liquid water for each of the radiation qualities. Frequency distributions of specific energy were calculated according to the formalism of Kellerer and Chmelevsky. Results indicate that the magnitude of the microdosimetric spread increases with decreasing target size and decreasing energy of the radiation quality. Within the clinical relevant dose range (1 to 100 Gy), the spread does not exceed 4 % for (60)Co, 5 % for (192)Ir and 6 % for (125)I. The frequency distributions can be accurately approximated with symmetrical normal distributions at doses down to 0.2 Gy for (60)Co, 0.1 Gy for (192)Ir and 0.08 Gy for (125)I.

Análisis de la insuficiencia de órganos y mortalidad en la sepsis por peritonitis secundaria / Analysis of organ failure and mortality in sepsis due to secondary peritonitis

Objetivos Identificar los órganos más propensos a desarrollar el síndrome de insuficiencia multiorgánica (MODS) en pacientes con sepsis por peritonitis secundaria. Determinar el valor evolutivo y predictivo de mortalidad del sistema Sequential Organ Failure Assessment (SOFA).Diseño Estudio de cohorte observacional prospectivo. Ámbito La unidad de reanimación (UR) de nuestro centro, un hospital universitario de tercer nivel. Pacientes Estudio prospectivo y observacional sobre 102 pacientes con sepsis de origen abdominal e insuficiencia de al menos un órgano relacionado con la infección. Se registraron las características demográficas, el origen abdominal de la sepsis, la mortalidad a los 28 días y la puntuación SOFA diaria. Resultados La mortalidad a los 28 días fue del 55%. El 53% de los pacientes presentaron fracaso de 2 o más órganos en el primer día de estancia. La puntuación SOFA media diaria fue significativamente mayor en los pacientes fallecidos a partir del cuarto día de estancia. Las variables que se asociaron a una mayor mortalidad de manera estadísticamente significativa fueron: MODS (p=0,000), fallo sistema nervioso central (p=0,000) y puntuación SOFA al cuarto día de estancia (p=0,012). El área bajo la curva ROC expresó una capacidad predictiva de mortalidad el SOFA cuarto día de estancia del 0,703 (IC 95%, 0,538-0,853 y p=0,026. El mejor poder discriminativo se observó para el MODS con área bajo la curva ROC del 0,776 (IC 95%, 0,678-0,874 y p=0,000).Conclusiones La evolución en la insuficiencia de órganos determinada por medio de SOFA mostró una alta precisión siendo un buen predictor de mortalidad la puntuación SOFA media cuarto día de estancia. El MODS fue la principal causa de muerte y el fracaso del sistema nervioso central, función renal y sistema respiratorio los factores de riesgo de muerte (AU)

Objectives To identify the organs most susceptible to develop multiorgan dysfunction syndrome (MODS) in patients with sepsis due to secondary peritonitis, and to determine the outcome and mortality predicting utility of the SOFA (Sequential Organ Failure Assessment) system. Design A prospective, observational cohort study was made. Setting The resuscitation unit of a third-level university hospital. Patients A prospective, observational cohort study was made of 102 patients with sepsis of abdominal origin and failure of at least one organ related to the infection. The demographic characteristics were documented, along with the abdominal origin of sepsis, mortality after 28 days, and the daily SOFA score. Results The mortality rate after 28 days was 55%. A total of 53% of the patients presented failure of two or more organs on the first day of admission. The mean daily SOFA score was significantly higher among the patients that died after day 4 of admission. The variables showing a statistically significant correlation to increased mortality were: MODS (P=.000), central nervous system failure (P=.000) and SOFA score on day 4 of admission (P=.012). The area under the ROC curve showed the mortality predicting capacity of the SOFA score on day 4 of admission to be 0.703 (95%CI 0.538-0.853; P=.026). The maximum discriminating capacity was recorded for MODS, with an area under the ROC curve of 0.776 (95%CI 0.678-0.874; P=.000).Conclusions Organ failure outcome as predicted by the SOFA score showed high precision - the mean SOFA score on day 4 of admission being a good mortality predictor. MODS was the main cause of death, while central nervous system, renal and respiratory failure were identified as the mortality risk factors (AU)

[Analysis of organ failure and mortality in sepsis due to secondary peritonitis]. / Análisis de la insuficiencia de órganos y mortalidad en la sepsis por peritonitis secundaria.

OBJECTIVES: To identify the organs most susceptible to develop multiorgan dysfunction syndrome (MODS) in patients with sepsis due to secondary peritonitis, and to determine the outcome and mortality predicting utility of the SOFA (Sequential Organ Failure Assessment) system. DESIGN: A prospective, observational cohort study was made. SETTING: The resuscitation unit of a third-level university hospital. PATIENTS: A prospective, observational cohort study was made of 102 patients with sepsis of abdominal origin and failure of at least one organ related to the infection. The demographic characteristics were documented, along with the abdominal origin of sepsis, mortality after 28 days, and the daily SOFA score. RESULTS: The mortality rate after 28 days was 55%. A total of 53% of the patients presented failure of two or more organs on the first day of admission. The mean daily SOFA score was significantly higher among the patients that died after day 4 of admission. The variables showing a statistically significant correlation to increased mortality were: MODS (P=.000), central nervous system failure (P=.000) and SOFA score on day 4 of admission (P=.012). The area under the ROC curve showed the mortality predicting capacity of the SOFA score on day 4 of admission to be 0.703 (95%CI 0.538-0.853; P=.026). The maximum discriminating capacity was recorded for MODS, with an area under the ROC curve of 0.776 (95%CI 0.678-0.874; P=.000). CONCLUSIONS: Organ failure outcome as predicted by the SOFA score showed high precision - the mean SOFA score on day 4 of admission being a good mortality predictor. MODS was the main cause of death, while central nervous system, renal and respiratory failure were identified as the mortality risk factors.

Anestesia general combinada con analgesia epidural para ureteroneocistostomía en un paciente con síndrome de Cornelia de Lange / General anaesthesia combined with epidural analgesia for ureteroneocystostomy in a patient with Cornelia de Lange syndrome

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Anestesia en el paciente con alteración de la función hepática / Anesthesia in the patient with impaired liver function

Se ha analizado la información relevante relacionada con la alteración de la función hepática y el acto anestésico y la reanimación postoperatoria. Se ha analizado de manera sistemática la afectación hepática por sistemas y las complicaciones del paciente cirrótico según el tipo de cirugía. La corrección de la coagulopatía en el paciente cirrótico es especialmente controvertida, ya que la expansión de volumen puede ser un factor de sangrado al incrementar la presión portal y producir un desequilibrio entre los factores pro y anticoagulantes. La morbilidad y mortalidad perioperatorias se correlacionan bien con la clasificación de Child-Pugh y el MELD, de forma que los pacientes con Child A tienen un riesgo moderado y por ello no se contraindica la cirugía. Por el contrario, los pacientes en la clase C o con un valor de MELD superior a 20, no deben ser intervenidos de forma electiva por el elevado riesgo que tienen. En general se considera que la cirugía abdominal es de alto riesgo, ya que altera el flujo sanguíneo hepático y facilita la hemorragia quirúrgica debida a la hipertensión portal(AU)

We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures(AU)

[Anesthesia in the patient with impaired liver function]. / Anestesia en el paciente con alteración de la función hepática.

We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures.