Objective To construct and validate of a nomogram predictive model for high-volume lymph node metastasis(HVM)in multifocal papillary thyroid carcinoma(MPTC).Methods Between January 2010 to January 2024,a total of 1146 and 234 patients with multifocal papillary thyroid carcinoma(MPTC)were diagnosed at Hangzhou First People's Hospital(Center A)and Hangzhou Cancer Hospital(Center B),respectively.Patients from Center A were randomly allocated to training set(n=803)and testing set(n=343)in a 7:3 ratio,while those from Center B(n=234)comprised an external validation set.Independent risk factors for HVM in MPTC patients were identified through univariate and multivariate Logistic regression analysis in training set,leading to the development of a nomogram predictive model.The generalizability of this model was subsequently assessed using both testing set and external validation set.The area under the curve(AUC)of receiver operating characteristic curve,sensitivity,and specificity evaluate the discriminative ability of the model.Results The incidence of HVM was 13.3％at center A and 12.8％at center B.Logistic regression identified male gender(OR=2.91,95％CI:1.835-4.599),maximum lesion diameter(OR=1.05,95％CI:1.021-1.070),and age(OR=0.95,95％CI:0.936-0.972)as independent risk factors for HVM.Anomogram based on these factors showed an AUC of 0.767 with 72.6％sensitivity and 70.2％specificity in training set,and 0.838 with 94.9％sensitivity and 68.4％specificity in testing set,and 0.769 with 63.3％sensitivity and 84.3％specificity in external validation set.The calibration curve demonstrated good agreement with the ideal curve.Conclusion The prediction model constructed based on clinical risk factors can effectively predict the probability of HVM in MPTC patients.

Objective:To analyze the clinical characteristics, diagnosis and treatment of 3 children with severe COVID-19 encephalopathy, targeted to improve the clinicians′ understanding of the disease.Methods:The clinical features, laboratory examinations, imaging data and diagnosis and treatment process of 3 cases of severe COVID-19 encephalopathy admitted to the Pediatric Intensive Care Unit of Shengjing Hospital of China Medical University from December 1, 2022 to December 31, 2022 were retrospectively analyzed.Results:Among the 3 patients, 2 were female, age was 2-11 years old, all of them had 2-3 days of medical history, all of them had clinical manifestations of high fever(≥40 ℃), convulsions and consciousness disorders, nucleic acid and antigen tests of SARS-CoV-2 were positive, and mycoplasma pneumonia IgM antibody was positive in 1 case.Within 24 hours after admission, the levels of white blood cells were basically normal, neutrophil fraction was dominant, and procalcitonin was significantly increased.Total T cells and NK cells in the blood of the three patients were significantly decreased, and the levels of blood ammonia, blood glucose and bilirubin were basically normal.In the early stage of the disease, the cell counts of the cerebrospinal fluid was normal in all the three patients, the protein level was significantly increased, there were new symmetrical lesions on head magnetic resonance imaging in 3 patients.After symptomatic treatment and immunotherapy including early use of hormone, human gamma globulin and plasma exchange, all the patients were survived, but had different degrees of new dysfunction of the nervous system.Conclusion:Severe COVID-19 encephalopathy can occur in the acute phase of SARS-CoV-2 infection, mostly manifested as high fever, convulsions and severe disturbance of consciousness, combined with multiple organ dysfunction and irreversible nervous system damage.Early supportive treatment, brain protective treatment and immunotherapy are helpful to improve the prognosis of patients.

Objective:To analyze the clinical characteristics, diagnosis and treatment of 3 children with severe COVID-19 encephalopathy, aiming to improve the clinicians′ understanding of the disease.Methods:The clinical features, laboratory examinations, imaging data and diagnosis as well as treatment process of 3 cases of severe COVID-19 encephalopathy admitted to the Pediatric Intensive Care Unit of Shengjing Hospital of China Medical University from December 1, 2022 to December 31, 2022 were retrospectively analyzed.Results:Among the 3 patients, 2 were female, age was 2-11 years old, all of them had 2-3 days of medical history.All of them had clinical manifestations of high fever(≥40 ℃), convulsions and consciousness disorders, nucleic acid and antigen tests of SARS-CoV-2 were positive, and mycoplasma pneumonia IgM antibody was positive in 1 case.Within 24 hours after admission, the levels of white blood cells were basically normal, neutrophil fraction was dominant, and procalcitonin was significantly increased.Total T cells and NK cells in the blood of the three patients were significantly decreased, and the levels of blood ammonia, blood glucose and bilirubin were basically normal.During the early stage of the disease, the cell counts of the cerebrospinal fluid was normal in all three patients, the protein level was significantly increased, and there were new symmetrical lesions on head magnetic resonance imaging in 3 patients.After symptomatic treatment and immunotherapy including early use of hormone, human gamma globulin and plasma exchange, all patients were survived, but had different degrees of new dysfunction of the nervous system.Conclusion:Severe COVID-19 encephalopathy can occur in the acute phase of SARS-CoV-2 infection, mostly manifested as high fever, convulsions and severe disturbance of consciousness, combining with multiple organ dysfunction and irreversible nervous system damage.Early supportive treatment, brain protective treatment and immunotherapy are helpful to improve the prognosis of the patients.

Background Subways are typical congregate settings and may facilitate aerosol transmission of viruses. However, quantified transmission probability estimates are lacking. Purpose To model spread and diffusion of respiratory aerosols in subways by simulation and calculation of infection probabilities. Methods The internal environment of carriages of Shanghai Metro Line 10 was used to establish a study scene. The movement of tiny particles was simulated using the turbulent model. Trend analysis of infection probabilities and viral quantum doses was conducted in a closed subway carriage scene by a quantum emission-infection probability model. Results Under a typical twelve-vent air conditioning configuration, respiratory droplet aerosols within a subway carriage dispersed rapidly throughout various regions due to airflow, with limited short-term diffusion to other carriages. Concurrently, owing to the uncertainty of airflow patterns, the airflow might circulate and converge within carriages, causing delayed outward dispersion or hindered dispersion of droplet aerosols upon entry into these zones. Passengers boarding the carriage could exacerbate the formation of these zones. When the air conditioning system functioned adequately (air exchange rate=23.21 h⁻¹), the probability of a virus carrier transmitting the virus to other passengers within the same carriage via aerosol transmission was approximately 3.8%. However, in the event of air conditioning system failure (air exchange rate=0.5 h⁻¹), this probability escalated dramatically to 30%. Furthermore, a super-spreader (with virus spreading exceeding 90% of the average) elevated the infection probability to 14.9%. Additionally, due to the complexity of turbulence within the carriage, if local diffusion occurred in 1/2 zones of a carriage, the anticipated infection probability would increase to 8.9%, or during the morning or evening rush hours leading to elevated aerosol concentrations, the infection probability would rise to 4.7%. The subway transmission probability for common coronaviruses diminished to as low as 0.9%. Conclusion Combined computational fluid dynamics and infection probability analysis reveals that in the prevalent twelve-vent air conditioning configurations, despite being a major transportation hub with substantial spatial-temporal overlap, the internal space of subway carriages exhibits a certain level of resistance to virus aerosol transmission owing to built-in ventilation capabilities. However, turbulence and passenger positioning may lead to localized hovering of droplet aerosols, thereby increase the risk of virus transmission. Furthermore, super-spreaders, poor operational status of built-in air conditioning system, and high passenger volume at morning or evening peak hours exert profound effects on virus transmission and infection probability.

Objective:To analyze and summarize the clinical characteristics, diagnosis and treatment, head imaging changes and prognosis of acute necrotizing encephalopathy of childhood (ANEC), aiming to improve the understanding of this disease.Methods:Clinical data of 13 ANEC patients (there were 7 males and 6 females, the median age was 30 months) admitted to the Pediatric Intensive Care Unit (PICU) of Shengjing Hospital, China Medical University from January 2014 to December 2020 were retrospectively analyzed, including clinical manifestations, laboratory examinations, diagnosis and treatment procedures, and head imaging data.Survivors were followed up through telephone.Results:All patients had fever and convulsions before admission, and the median time between fever and consciousness disturbance was 48 hours.The magnetic resonance imaging scans showed symmetrical multifocal brain damages.All 13 patients used glucocorticoid treatment, 10 cases used human immunoglobulin treatment, 8 cases used plasma exchange treatment.A total of 7/13 patients died.Five children were regularly followed up, who presented normal height and weight development and normal immunity.One child had normal motor intelligence with the acceptable Pediatric Overall Performance Category Score, and the remaining 4 children had certain sequelae, mainly manifesting as slow speech speed and limited movement.Conclusions:ANEC mainly occurs in winter and young children with a high mortality.It progresses rapidly, and consciousness disturbance appears soon after fever and convulsion.Survivors usually have sequelae, mostly manifesting as slow speech speed and limited movement, which can be significantly improved after systematic rehabilitation treatment.

Objective:To explore the feasibility of the clinical implementation of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans with 6MV photon on two Elekta Linacs (Versa HD and Synergy) after beam matching.Methods:The images of 12 patients with nasopharyngeal carcinoma, central lung cancer and prostate cancer were randomly selected, and the IMRT and VMAT plans were designed. Two different dose tools of ionization chamber and three-dimensional detector ArcCheck were used to verify the individualized radiation treatment of 6MV photon beams on two Linacs and compare the differences.Results:The deviations between the doses of two Linacs (Versa HD and Synergy) measured by the ion chamber and treatment planning system were (0.32±1.32)% and (0.54±1.29)%. The differences of all plans were within the range of ±3%, and the deviations of the point dose between two Linacs were within the range of ±2% with no statistical significance (both P>0.05). The γ analysis of verification using ArcCheck showed that the passing rates of all plans under the 2mm/3% and 3mm/3% with 10% threshold conditions were over 95%, respectively. The average differences between two Linacs were 0.19%(2mm/3%) and 0.09%(3mm/3%). Conclusions:The results of performing IMRT/VMAT plans on two Linacs meet the clinical requirements and the differences between two Linacs are small. Hence, the same plans can be implemented interchangeably on different Linacs.

Objective:To investigate the risk factors for death in children with acute necrotizing encephalopathy (ANE) in pediatric intensive care unit (PICU).Methods:This was a multicenter retrospective study. Thirty-nine children with ANE were from PICUs in 4 centers from December 1, 2014 to December 1, 2020. The 4 participating centers were Beijing Children′s Hospital, Shengjing Hospital of China Medical University, Hebei Children′s Hospital, and Bao′an Maternity & Child Health Hospital. Patients were divided into survival and non-survival groups by the outcome at discharge, and the differences in clinical data between the two groups were compared. Risk factors for death in children with ANE and the odds ratios ( OR) were analyzed by univariable Logistic regression. Results:Thirty-nine children with ANE were included. There were 18 males and 21 females. The median onset age was 30 months. The mortality at discharge was 41% (16/39). The onset age of most patients (74%, 29/39) was younger than 4 years old. Influenza virus was the most common precursor infection (80%, 20/25). Patients with shock at PICU admission were more common in the non-survival group (12/16 vs. 17% (4/23), P=0.001). Glasgow coma score (GCS) at PICU admission was significantly lower in the non-survival group than survival group (3 (3, 6) vs. 6 (5, 7), Z=-2.598, P=0.009). The optimal cut-off value was 4. The proportion of patients with GCS ≤ 4 at PICU admission was higher in the non-survival group (10/16 vs. 22% (5/23), P=0.018). ANE severity score (ANE-SS) at PICU admission was significantly higher in the non-survival group (5 (2, 6) vs. 2 (1, 4), Z=-2.436, P=0.015). The proportion of patients with high risk ANE-SS was higher in non-survival group than the survival group (9/16 vs. 22% (5/23), P=0.043). The proportion of application of high-dose methylprednisolone (20 mg/(kg·d)) was significantly higher in survival group than non-survival group (43% (10/23) vs. 1/13, P=0.031). Univariable Logistic regression indicated that risk factors for death in children with ANE were shock ( OR=14.250, 95% CI 2.985-68.018, P=0.001), GCS≤4 ( OR=6.000, 95% CI 1.456-24.733, P=0.013) and high risk ANE-SS ( OR=4.629, 95% CI 1.142-18.752, P=0.032) at PICU admission. Conclusions:ANE usually occurs in children under 4 years old after influenza infection. Shock, GCS≤4 and high risk ANE-SS at PICU admission were risk factors for death in children with ANE. High-dose methylprednisolone may improve the prognosis of children with ANE.

Objective: To study the dosimetric characteristics and plan quality of PTV-based intensity modulated proton radiotherapy (IMPT) and volumetric-modulated arc therapy (VMAT) plans for prostate cancer, so as to provide a reference for clinical application. Methods: A total of 10 prostate cancer cases were included in this retrospective study. IMPT and RapidArc plans were designed by RayStation and Eclipse TPS based on PTV, respectively. For each case, IMPT plans were generated using multiple field optimization (MFO) technique with two parallel-opposed lateral fields, whereas RapidArc plans were generated using double-arc technique (two full arcs). Final dose calculation of IMPT was conducted by pencil beam(PB) and Monte Carlo (MC) algorithm, respectively, with adopted data model from the pencil beam scanning (PBS) proton therapy system of IBA Protues Plus(IBA Group, Belgium); The data model originated from the linear accelerator of Varian Clinac iX (Varian Medical Systems, America) was used for RapidArc plans. Dosimetric parameters of DVH and dose distribution were used to compare the dose differences in targets and organs at risk (OARs) between these two treatment techniques. Results: For targets, HIs of PB-IMPT and MC-IMPT were slightly better than that of RapidArc , but CI of IMPT was slightly lower than that of RapidArc; D_1% of PB-IMPT was significantly better than those of MC-IMPT and RapidArc (Z=-2.805, -2.803, P<0.05). PB-IMPT and MC-IMPT achieved better protection than RapidArc on rectum V₃₀(Z=-2.191, -1.988, P<0.05)and D_mean(Z=-2.599, -2.497, P<0.05), bladder V₃₀(Z=-2.701, -2.701, P<0.05), V₄₀(Z=-2.395, -2.395, P<0.05)and D_mean(Z=-2.701, -2.701, P<0.05). There was no significant difference between PB-IMPT and MC-IMPT plans for prostate cancer, except for the D_1% [(73.86±67.34) Gy vs.(75.45±2.01) Gy] (RBE) and HI [(0.040±0.010) vs. (0.058±0.020)] of the target. Conclusions Both techniques can meet the clinical requirements, but IMPT showed significant dosimetric advantages compared with RapidArch by reducing the dose to OARs and improving the plan quality.

Flash radiotherapy is a kind of radiotherapy method using ultra-high dose rate radiation. Compared with the traditional dose rate radiotherapy, it has unique radiobiological advantages. In this paper, the principle of flash radiotherapy, the process and results of biological experiments are summarized. At the same time, the advantages and challenges of flash radiotherapy are analyzed, and the future clinical application is prospected.
Radiotherapy/methods* ; Radiotherapy Dosage ; Technology

Septic cardiomyopathy is a common complication in severe sepsis and septic shock,mito‐chondrial function injury is one of the main aspects of its pathogenesis. The heart is a continuous power or‐gan,needs a lot of ATP to maintain normal systolic and diastolic function. Mitochondrial as the main ATP producing organelles,accounts for about one third of the myocardial volume,which being damaged will be harmful to the myocardial energy supply and cardiac function. This paper introduced the latest research pro‐gress of mitochondrial damage in septic cardiomyopathy,including mitochondrial NO production increase and oxidative stress,Ca2+ overload and mitochondrial membrane permeability increase,mitochondrial uncoupling and mitochondrial homeostasis,also discussed the potential treatments.