Objective:To calculate the single-event dose-averaged specific energy of particles delivered in spherical domains based on the track structure model and using triple integration, and to investigate the influence of the domain shape on the key model parameters of microdosimetric kinetic model (MKM) and its corresponding physical significance.Methods:The domains are assumed to be cylinders and spheres, respectively. With α 0, domain radius, rd, and nucleus radius, Rn, as undetermined coefficients, the nuclear charge numbers, kinetic energies and their corresponding LETs of three kinds of charged particles ( 3He, 12C, 20Ne) as independent variables, D10 as dependent variable, the mean value of squared residuals, J2, between the D10 calculated values and D10 experimental values as the optimization objective, the final fitting values of the above undetermined coefficients of human salivary gland (HSG) cells and Chinese hamster lung (V79) cells obtained after iteration by the robust least square method are the optimal model parameter values of MKM. Results:For HSG cells, cylindrical domain: α 0=0.073/Gy, rd=0.29 μm, Rn=4.1 μm, J2=0.039 7 Gy 2; spherical domain: α 0=0.023/Gy, rd=0.29 μm, Rn=4.4 μm, J2=0.039 3 Gy 2; For V79 cells, cylindrical domain: α 0=0.114/Gy, rd=0.25 μm, Rn=3.8 μm, J2=0.097 4 Gy 2; spherical domain: α 0=0.095/Gy, rd=0.26 μm, Rn=4.1 μm, J2=0.096 9 Gy 2. Conclusions:For the same type of cells, cylindrical and spherical domains were selected respectively, and there are significant differences in MKM parameters obtained by fitting. The fitting values of the domain radius, rd of the two shapes of domains show no significant difference, while the fitting values of α0 of spherical domains are smaller than those of cylindrical domains, the fitting values of nucleus radius, Rn, of spherical domain are larger than those of cylindrical domains, closer to the nucleus radius observed by fluorescence microscopy. In the low LET (<20 keV/μm) region, D10 calculated according to the parameters of the two different shapes of domains are different, so the selection of the domain shape will cause differences in the relative biological effectiveness(RBE) calculation of proton in the region near Bragg peak.

OBJECTIVE: To investigate the feasibility of MRI three-dimensional (3D) reconstruction model in quantifying glenoid bone defect by comparing with CT 3D reconstruction model measurement. METHODS: Forty patients with shoulder anterior dislocation who met the selection criteria between December 2021 and December 2022 were admitted as study participants. There were 34 males and 6 females with an average age of 24.8 years (range, 19-32 years). The injury caused by sports injury in 29 cases and collision injury in 6 cases, and 5 cases had no obvious inducement. The time from injury to admission ranged from 4 to 72 months (mean, 28.5 months). CT and MRI were performed on the patients' shoulder joints, and a semi-automatic segmentation of the images was done with 3D slicer software to construct a glenoid model. The length of the glenoid bone defect was measured on the models by 2 physicians. The intra-group correlation coefficient ( ICC) was used to evaluate the consistency between the 2 physicians, and Bland-Altman plots were constructed to evaluate the consistency between the 2 methods. RESULTS: The length of the glenoid bone defects measured on MRI 3D reconstruction model was (3.83±1.36) mm/4.00 (0.58, 6.13) mm for physician 1 and (3.91±1.20) mm/3.86 (1.39, 5.96) mm for physician 2. The length of the glenoid bone defects measured on CT 3D reconstruction model was (3.81±1.38) mm/3.80 (0.60, 6.02) mm for physician 1 and (3.99±1.19) mm/4.00 (1.68, 6.38) mm for physician 2. ICC and Bland-Altman plot analysis showed good consistency. The ICC between the 2 physicians based on MRI and CT 3D reconstruction model measurements were 0.73 [95% CI (0.54, 0.85)] and 0.80 [95% CI (0.65, 0.89)], respectively. The 95% CI of the difference between the two measurements of physicians 1 and 2 were (-0.46, 0.49) and (-0.68, 0.53), respectively. CONCLUSION The measurement of glenoid bone defect based on MRI 3D reconstruction model is consistent with that based on CT 3D reconstruction model. MRI can be used instead of CT to measure glenoid bone defects in clinic, and the soft tissue of shoulder joint can be observed comprehensively while reducing radiation.
Male ; Female ; Humans ; Young Adult ; Adult ; Imaging, Three-Dimensional/methods* ; Tomography, X-Ray Computed/methods* ; Joint Instability ; Shoulder Joint/diagnostic imaging* ; Shoulder Dislocation ; Magnetic Resonance Imaging/methods*

Brain arteriovenous malformation (bAVM) is a common cerebrovascular disease in clinical practice. Compared with adults, children with bAVM are more prone to rupture and bleeding, and have a higher mortality and disability. Therefore, it is very important to accurately evaluate the bleeding risk of children with bAVM and reasonably select intervention measures to improve the prognosis. The treatment methods of children with bAVM mainly include conservative treatment, microsurgical treatment, endovascular embolization, stereotactic radiosurgery, and multimodal combined treatment. At present, the treatment indications and specific treatment options for children with bAVM are controversial.

Objective:In Shanghai Advanced Proton Therapy Facility (SAPT) of Ruijin Hospital Proton Therapy Center, the calculation accuracy of the commercial proton treatment planning system RayStation (V10), especially the accuracy of the proton range calculation, was measured and verified, aiming to provide reference for the clinical application of the treatment planning system.Methods:A head phantom was used to verify the calculation accuracy of RayStation. The phantom CT was imported into treatment planning system (TPS). The phantom was followed closely by a water tank with a one-liter cubic target. A single field verification plan with the prescribed dose of 200 cGy (relative biological effectiveness) was designed and implemented. Then, the measured distribution results were compared with the calculation results.Results:When the verification plan of the phantom was designed with the default settings of RayStation, the measured longitudinal dose distribution was approximately 4 mm deeper than that of TPS, indicating that RayStation overestimated the water equivalent thickness (WET) of the tissue substitute materials in the phantom. To study the range error, the actual beam was used to measure the WET of the soft tissue substitute material. The default setting of RayStation was fine-tuned according to the measured results. It was found that the error between the measured SOBP and TPS calculations was reduced to only 2 mm.Conclusions:Using the default setting of RayStation to calculate the stopping power of the phantom may cause a large range error. A method that combines tissue segmentation with the measured WET of the tissue substitute material is proposed to improve the range calculation accuracy of the TPS. The results show that the proposed method can improve the dose and range accuracy of the commercial TPS including RayStation for tissue substitute materials.

BACKGROUND: Perioperative treatment has become an increasingly important aspect of the management of patients with non-small cell lung cancer (NSCLC). Small-scale clinical studies performed in recent years have shown improvements in the major pathological remission rate after neoadjuvant therapy, suggesting that it will soon become an important part of NSCLC treatment. Nevertheless, neoadjuvant immunotherapy may be accompanied by serious adverse reactions that lead to delay or cancelation of surgery, additional illness, and even death, and have therefore attracted much attention. The purpose of the clinical recommendations is to form a diagnosis and treatment plan suitable for the current domestic medical situation for the immune-related adverse event (irAE). METHODS: This recommendation is composed of experts in thoracic surgery, oncologists, thoracic medicine and irAE related departments (gastroenterology, respirology, cardiology, infectious medicine, hematology, endocrinology, rheumatology, neurology, dermatology, emergency section) to jointly complete the formulation. Experts make full reference to the irAE guidelines, large-scale clinical research data published by thoracic surgery, and the clinical experience of domestic doctors and publicly published cases, and repeated discussions in multiple disciplines to form this recommendation for perioperative irAE. RESULTS: This clinical recommendation covers the whole process of prevention, evaluation, examination, treatment and monitoring related to irAE, so as to guide the clinical work comprehensively and effectively. CONCLUSIONS Perioperative irAE management is an important part of immune perioperative treatment of lung cancer. With the continuous development of immune perioperative treatment, more research is needed in the future to optimize the diagnosis and treatment of perioperative irAE.

The World Health Organization (WHO) released the WHO 2020 guidelines on physical activity and sedentary behaviour in November 2020. Compared with the 2010 WHO guidelines, this guideline has incorporated more extensive medical evidence and made targeted recommendations for special populations. The main content includes physical activity and sedentary behaviour advice for children and adolescents, adults, older adults, pregnant and postpartum women, people with chronic conditions, and disability. This review will interpret the 2020 WHO guidelines in detail.

Objective:To investigate whether the combination of the advantages of deep learining in image processing and radiotherapy will make the radiotherapy process more intelligent.Methods:The generative adversarial network (GAN) is a generation model using neural network. High-quality dose distribution images can be generated by inputting relevant features. Firstly, random unconditional GAN was utilized to verify the ideal data, then conditional GAN (cGAN) was employed to train DICOMRT data of tumor patients, and the target contour information was used to directly generate dose distribution images.Results:For the verification of ideal data, the generation of ideal distribution yielded good effect. By extracting target contour and real dose slice data and using cGAN training, the dose distribution maps of planning target volume (PTV) and organs at risk (OAR) of tumor patients could be obtained. The absolute error evaluation of the maximum and average values between the predicted value and the real dose was shown as[3.57%, 3.37%](PTV), [2.63%, 2.87%](brain), [1.50%, 2.70%](CTV), [3.87%, 1.79%](GTV), [3.60%, 3.23%](OAR1) and[4.40%, 3.13%](OAR2), respectively.Conclusions:GAN model can be used to generate ideal dose distribution data, and cGAN model with prior knowledge can be employed to establish the relationship between target information and dose distribution. Directly generating the corresponding dose distribution image by inputting the target contour information is an effective attempt for dose prediction.

Osteonecrosis is the most common disorder in femoral head and scaphoid. However, avascular necrosis (AVN) in metacarpal head is a rare disease. In the present study, a 14-year-old male patient complained of right-hand pain with a limited range of motion for one month. Physical examination showed that the active flexion was 70° and the extension was limited to 30° of the metacarpophalangeal (MCP) joints. The grip strength decreased to 60% of the contralateral hand. X-rays demonstrated flattening and sclerotic changes in the long finger and ring finger of metacarpal head. CT scanning indicated cystic, osteochondral defects and sclerotic changes in metacarpal head. Imaging examination further confirmed the diagnosis of AVN in the long metacarpal finger and ring finger. After conservative treatments including splint immobilization, non-steroidal anti-inflammatory drugs (NSAIDs) and physiotherapy, the local pain symptoms of the MCP joint gradually disappeared. The range of motion of MCP joint returned to normal with the grip strength score as 105% of the contralateral hand. MRI confirmed excellent remodeling and regeneration in the metacarpal head at two years later. The clinical characteristics, diagnosis and treatments of AVN of metacarpal head were reviewed. Although radiograph examination is commonly used, early-stage osteonecrosis of the metacarpal head should be confirmed by MRI. Given the rarity of this disorder, there is no consensus on the treatments. Metacarpal necrosis is the more common disorder in adolescent patients with a history of trauma. Considering the potential of bone remodeling, juveniles with metacarpal head necrosis could recover by conservative treatments.

Since December 2019, a novel coronavirus (2019-nCoV, SARS-CoV-2) pneumonia (COVID-19) outbreak has occurred in Wuhan, Hubei Province, and the epidemic situation has continued to spread. Such cases have also been found in other parts of the country. The spread of the novel coronavirus pneumonia epidemic has brought great challenges to the clinical practice of thoracic surgery. Outpatient clinics need to strengthen the differential diagnosis of ground glass opacity and pulmonary plaque shadows. During the epidemic, surgical indications are strictly controlled, and selective surgery is postponed. Patients planning to undergo a limited period of surgery should be quarantined for 2 weeks and have a nucleic acid test when necessary before surgery. For patients who are planning to undergo emergency surgery, nucleic acid testing should be carried out before surgery, and three-level protection should be performed during surgery. Patients who are planning to undergo emergency surgery in the epidemic area should be confirmed with or without novel coronavirus pneumonia before operation, and perform nucleic acid test if necessary. Surgical disinfection and isolation measures should be strictly carried out. Among postoperative patients, cases with new coronavirus infection were actively investigated. For the rescue of patients with novel coronavirus infection, attention needs to be paid to prevention and treatment and related complications, including mechanical ventilation-related pneumothorax or mediastinal emphysema, and injury after tracheal intubation.

OBJECTIVE: To investigate the effects of blocking the activation of ERK pathway on the expression of matrix metalloproteinase-9 (MMP-9) and the formation of cerebral edema in SD rats after brain injury. METHODS: Ninety SD rats were randomly divided into 3 equal groups, including a sham-operated group, modified Feeney's traumatic brain injury model group, and ERK inhibition group where the ERK inhibitor SCH772984 (500 μg/kg) was injected via the femoral vein 15 min before brain trauma. At 2 h and 2 days after brain trauma, the permeability of blood-brain barrier was assessed by Evans blue method, the water content of the brain tissue was determined, and the phosphorylation level of ERK and the expression level of MMP-9 mRNA and protein were measured by RT-PCR and Western blotting. RESULTS: Compared with the sham-operated group, the rats with brain trauma exhibited significantly increased level of ERK phosphorylation at 2 h and significantly increased expression of MMP-9 mRNA and protein 2 days after the injury ( < 0.01). Treatment with the ERK inhibitor significantly decreased the phosphorylation level of ERK after the injury ( < 0.01), suppressed over-expression of MMP-9 mRNA and protein 2 days after the injury ( < 0.01). The permeability of blood-brain barrier increased significantly 2 h after brain trauma ( < 0.05) and increased further at 2 days ( < 0.01); the water content of the brain did not change significantly at 2 h ( > 0.05) but increased significantly 2 d after the injury ( < 0.01). Treatment with the ERK inhibitor significantly lowered the permeability of blood-brain barrier and brain water content after brain trauma ( < 0.01). CONCLUSIONS Blocking the activation of ERK pathway significantly reduced the over-expression of MMP-9 and alleviates the damage of blood-brain barrier and traumatic brain edema, suggesting that ERK signaling pathway plays an important role in traumatic brain edema by regulating the expression of MMP-9.
Animals ; Brain Edema ; drug therapy ; etiology ; Brain Injuries, Traumatic ; complications ; drug therapy ; Gene Expression Regulation, Enzymologic ; drug effects ; Indazoles ; pharmacology ; therapeutic use ; MAP Kinase Signaling System ; drug effects ; Matrix Metalloproteinase 9 ; genetics ; Piperazines ; pharmacology ; therapeutic use ; Protein Kinase Inhibitors ; pharmacology ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley