Objective To present and discuss beam characteristics of the first Mevion S250i gantry-mounted accelerator pencil beam scanning proton therapy system in China.Methods The output dose was measured using a parallel-plate ionization chamber.The integrated depth dose was measured with a large-radius Bragg peak ionization chamber,covering 19 energy levels ranging from 227 MeV to 28 MeV,to analyze the proton beam characteristics.The spots in the air were measured with Phoenix flat panel detector on the beam central axis,and the precision of the delivery position was verified by measuring the multi-spot beam map.The interleaf leakage and penumbra reduction of adaptive aperture were measured to characterize its performance.Results The proton system was calibrated for a maximum energy of 227 MeV,with a(10×10)cm2uniform field delivering 1 Gy dose at a depth of 5 cm underwater.The system effectively modulated the proton beam range to the patient's surface,maintaining a constant 80%-80%Bragg peak width of 8.6 mm at all energy levels.The spot size of the highest energy beam at the isocenter was about 4 mm in the air,and the spot delivery position error was less than 1 mm.The interleaf leakage rate of the adaptive aperture for the highest energy beam was below 1.5%,and the penumbra was significantly reduced.Conclusion Mevion S250i proton therapy system demonstrates unique design and beam characteristics,which is reflected in the Bragg peak shape,spot size variation with energy,and penumbra sharpening of adaptive aperture;and these differences should be considered in treatment planning system modeling and planning for precision treatment.

Objective:To evaluate the clinical application value of the adaptive aperture by comparing intensity-modulated proton radiotherapy(IMPT) plans using and not using the aperture for brain tumors.Methods:A total of twenty patients treated with postoperative radiotherapy for brain tumors were enrolled in this study. IMPT plans were developed for each patient using and not using the adaptive aperture under the same optimization conditions. The target conformal index (CI) value, target homogeneity index (HI) value, and the dose to normal tissues of the two sets of plans were compared.Results:The IMPT plans designed using the adaptive aperture significantly increased the mean CI value from 0.58 to 0.66, while decreasing the mean 50% prescription dose volume from 797.70 cm 3 to 638.15 cm 3. These plans also reduced the irradiation doses to the cochlea, brainstem, optic chiasm, optic nerve, and lens ( t = 2.06, 3.02, 2.11, 2.58, 2.67, P < 0.05). Additionally, there was no significant difference in the HI value of the target volumes and the machine jumps (MU) between the two sets of plans ( P > 0.05). Conclusions:The adaptive aperture can significantly reduce the irradiation dose to normal tissues outside the target volumes, positively impacting the protection of organs at risk (OARs) around the target values. This demonstrates its great potential for clinical application.

Objective:To learn about the awareness of brucellosis prevention and control knowledge among people in key areas of Ningxia Hui Autonomous Region (Ningxia), and analyze influencing factors.Methods:From February to March 2023, a multi-stage stratified sampling method was adopted to select residents (aged ≥12 years and resident for ≥6 months) from Yanchi County, Litong District, Pingluo County and Yuanzhou District of Ningxia as the survey subjects. Demographic information such as gender, age, education level, marital status, occupation, region, urban-rural status, as well as knowledge of brucellosis prevention and control were obtained through face-to-face questionnaire surveys. The awareness rate of brucellosis prevention and control knowledge among various populations was calculated and the influencing factors were analyzed by binary logistic regression.Results:A total of 1 592 questionnaires were distributed, of which 1 581 were valid, with an effective rate of 99.31%. There were 704 males, accounting for 44.53% (704/1 581); and 877 females, accounting for 55.47% (877/1 581). The age was (54.09 ± 14.81) years old, ranging from 14 to 88 years old. The education level was mainly primary school or below, accounting for 48.07% (760/1 581). The marital status was mainly married or cohabitating, accounting for 91.84% (1 452/1 581). The occupation was mainly farmers and herdsmen, accounting for 61.92% (979/1 581). In Pingluo County, Litong District, Yuanzhou District and Yanchi County, 392, 403, 396 and 390 people were investigated, respectively. In urban and rural areas, 797 and 784 people were investigated, respectively. The overall awareness rate of brucellosis prevention and control knowledge among the population was 47.82% (756/1 581). Univariate analysis showed that there were statistically significant differences in the awareness rates of brucellosis prevention and control knowledge among different age groups, education levels, marital status, occupation, regions and urban and rural populations ( P < 0.05). Binary logistic regression analysis showed that age, education level, marital status, occupation, urban-rural status were the factors influencing the awareness rate of brucellosis prevention and control knowledge among the population ( P < 0.05). Conclusion:The awareness rate of brucellosis prevention and control knowledge in key areas of Ningxia is relatively low, and age, education level, marital status, occupation, and urban-rural status are the main influencing factors.

Objective:To systematically integrate qualitative research on the psychological experience of non-suicidal self-injury (NSSI) in adolescents.Methods:A comprehensive literature search was conducted in databases including China National Knowledge Infrastructure, WanFang data, VIP, China Biology Medicine disc, PubMed, Web of Science, Embase, and Cochrane Library for qualitative studies on the psychological experience of NSSI in adolescents and the search period covered the inception of the databases until June 27, 2023. The methodological quality of the included studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Qualitative Research (2016 edition). The results were integrated using the Meta-synthesis method.Results:A total of 15 studies were included, comprising ten phenomenological studies, one descriptive qualitative study, one mixed-method study, one narrative study, one exploratory study, and one grounded theory study. Thirty-one findings were extracted and synthesized into ten categories, resulting in three main themes: triggers of adolescent NSSI, NSSI as a coping strategy, and the internal conflict and struggle of adolescents engaging in NSSI.Conclusions:Adolescents engaging in NSSI experience complex psychological and sensory responses. Healthcare professionals should closely monitor adolescents' emotional changes, enhance psychological assessments, and guide them in coping with negative emotions effectively to improve their physical and mental health.

Objective To analyze the daily quality assurance(QA)measurement results of IBA Sphinx Compact device on the Mevion compact pencil beam scanning proton therapy system for evaluating its clinical application value in proton therapy.Methods The daily QA measurement of Mevion S250i proton therapy system was carried out with Sphinx Compact device for 30 consecutive days,and the measurement results were analyzed.Results The average deviation between the positioning laser and the image center was(0.42±0.27)mm in 30 days.All of the proximal and distal depth errors of the high-and low-energy pencil beams were within 0.50 mm.The position deviation of all the spots measured did not exceed 1.00 mm,and the size deviation was less than 7.5%.The deviation between the image center and the beam center was not more than 0.75 mm.The relative deviation of the flatness of the rectangular field was about 0.5%.The deviation of the output dose of the square field was within 1.0%.Conclusion The proton system daily QA measurement items recommended by AAPM TG-224 report can be accurately and rapidly measured with Sphinx Compact device.The device is a practical and efficient daily QA tool with high practical value in clinic.

Objective:To discuss the acceptance test of beam performance and mechanical precision of the first Mevion type S250i proton therapy system in China,and verify the stability and reliability of that in clinical treatment.Methods:According to the requirements of acceptance report of manufacturer,the output and range of machine unit(MU),the accuracy and stability of size and position of beam spot,the penumbra and position accuracy of adaptive aperture(AA)of Mevion type S250i proton therapy system,as well as the tests of mechanical properties and functions of the requirement of clinical use,were checked and tested for acceptance.Results:The maximum deviation of MU output was 1.3%,and the maximum deviation of the range was 0.037 g/cm2,and the maximum distal fall-off was 0.465 cm,and the minimum range of energy modulation was 0.21 g/cm2.The maximum deviations of the size of beam spot and the maximum deviation of the position were respectively 0.07 cm and 0.05 cm.The maximum AA penumbra was 0.007 cm,and the AA position accuracy was less than 0.1 cm.Conclusion:The acceptance test of the Mevion type S250i proton therapy system indicates that the parameters of the beam performance and mechanical precision can meet the requirements of the acceptance contract and AAPM-TG224 report of manufacturer,which has verified the machine has better favorable stability and reliability.

Objective:To measure and assess relevant radiation doses at the radiotherapy site of the first domestic single-vault proton therapy system.Methods:The radiation levels of the therapy system during and after beam irradiation were measured, and annual effective doses were assessed for personnel at the site.Results:During beam irradiation, the highest radiation dose was detected at the shielded door of the equipment floor, with a gamma radiation level of 2.140 μSv/h and a neutron radiation level of 0.850 μSv/h. Neutron radiation disappeared immediately once the beams stopped. In contrast, the radiation activated originated mostly from gamma rays. A longer time after beams stopped was associated with lower induced radiation intensity at the same location. Furthermore, a farther distance from the irradiated object corresponded to lower induced radiation intensity at the same time. The assessment result reveal that the annual effective doses to the personnel were at the safe level, with physicists exposed to the highest dose of 2.138 mSv.Conclusions:The radiation level at the studied proton therapy site meets the safety requirement, and the treatment can be performed safely at this site.

Objective:To verify and calibrate the CT modeling curves of three CT devices in RayStation proton treatment planning system (TPS).Methods:CT-mass density (CT-MD) curves were established by CT Hounsfield units of different tissue substitute materials obtained by scanning the model with CT equipment. CT-stopping power (CT-SP) curves were established by calculation based on the chemical composition of various human tissues. The equivalent water thickness of tissue substitute modules was calculated with different CT modeling curves in TPS. The actual equivalent water thickness of various modules was measured by a Bragg peak detector, and compared with the calculated values of TPS to verify the accuracy of different CT models.Results:The differences of CT modeling curves were significantly different under different tube voltage scanning protocols. Compared with CT-MD curves, CT-SP curves based on the stoichiometric calibration were more suitable for proton dose calculation. However, the values of stopping power corresponding to high CT values still needed to be optimized, and the calculation error after calibration was less than 3%.Conclusion:The method of verifying and calibrating CT unit curves of proton TPS is described, proving that the CT-SP curves after stoichiometric calculation are more suitable for proton dose calculation.

Background Plateau environment may pose a serious impact on the physiological and psychological stress of people stationed on a plateau, especially for those engaged in military training and occupational activities. There is an urgent need to find drugs to prevent and treat injuries caused by high-altitude environment. Objective To analyze the current status, hotspots, and future trends of domestic and international research in the field of prevention and treatment of high-altitude disease (HAD) by traditional Chinese medicine (TCM), and provide references for scientific research. Methods Web of Science Core Collection (WOSCC) and China National Knowledge Infrastructure (CNKI) were searched for literature on TCM and HAD published from inception to 2022. Excel, CiteSpace, VOSviewer, and RStudio softwares were used to conduct visual analysis on the number of publications, types of publications, journals, authors, research institutions, and keywords. Results A total of 501 publications were evaluated in the present study, including 443 Chinese publications and 58 English publications. The annual number of publications showed a rising trend. MA Huiping was the leading author in number of publications in Chinese (37 publications), and ZHANG Yi and MENG Xianli were the leading authors in the number of publications in English (both 8 publications), respectively. The institutions with the most publications in Chinese were The 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army and Lanzhou General Hospital of Lanzhou Military Region (both 32 publications), and the institution with the most publications in English was Chengdu University of Traditional Chinese Medicine (8 publications), respectively. The Chinese and English journals with the largest number of publications were the Journal of High Altitude Medicine (39 publications) and the Journal of Ethnopharmacology (10 publications), respectively. The most highly cited Chinese and English literature included Effects of rhodiola on the free radical metabolism and serum creatine kinase after exercise at plateau (61 citations) and Anti-hypoxic activity at simulated high altitude was isolated in petroleum ether extract of Saussurea involucrate (68 citations) , respectively. The most frequent keywords in the Chinese and English literature were high altitude polycythemia and oxidative stress, respectively. The keyword time zone and emergence maps showed that the research hotspots in this field shifted from prevention and treatment of HAD to animal experiments, and then to mechanisms of action, in which oxidative stress, hypoxic injury, inflammation, and apoptosis were the main focuses. Conclusion The research of TCM against HAD is identified from early clinical observation to associations between clinical outcome variation and pharmacological mechanisms, and further to applying multi-omics techniques to explore the physical basis of TCM efficacy and mechanisms of action with focuses like TCM formula and single herb active ingredients, so as to elaborate potential scientific connotation of TCM against HAD.

Objective     To explore the timing and safety of limited-period lung cancer surgery in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods     Clinical data of of patients infected with COVID-19 undergoing lung cancer surgery (an observation group) in the Department of Thoracic Surgery of Guangdong Provincial People's Hospital, the Department of Thoracic Surgery of General Hospital of Southern Theater Command of PLA, and the Department of Cardiothoracic Surgery of the First Affiliated Hospital of Guangdong Pharmaceutical University from December 2022 to January 2023 were retrospectively analyzed and compared with patients who underwent surgery during the same period but were not infected with COVID-19 (a control group), to explore the impact of COVID-19 infection on lung cancer surgery. Results     We finally included 110 patients with 73 patients in the observation group (28 males and 45 females at age of 52.62±12.80 years) and 37 patients in the control group (22 males and 15 females at age of 56.84±11.14 years). The average operation time of the observation group was longer than that of the control group, and the incidence of anhelation was higher than that of the control group (P<0.05). There were no statistcal differences in blood loss, length of hospital stay, moderate or above fever rate, degree of cough and chest pain, or blood routine between the two groups. Conclusion    It is safe and feasible to perform lung cancer surgery early after recovery for COVID-19 patients with lung cancer.