Persistent left superior vena cava is a rare venous variant that is often combined with cardiovascular malformations. In thoracic surgery, especially mediastinal tumor resection, neglect of this variant may make the surgery difficult and risky, and careful preoperative imaging interpretation and adequate preoperative evaluation play an important role in the perioperative safety of the patient. In this paper, we reported a case of a 17-year-old female patient with a persistent left superior vena cava combined with mediastinal tumors. She was successfully discharged 5 days after thoracoscopic surgery, and after 3 years of postoperative follow-up, no tumor recurrence was observed.

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 analyze the molecular characteristics of antibiotic resistance in Helicobacter pylori(HP)and provide a molecular bio-logical basis for clinical eradication of HP by means of rational antibiotic use.Methods:From February 2019 to November 2023,1,144 pa-tients at the Gansu Wuwei Cancer Hospital who tested positive for HP using the 14C-urea breath test were enrolled in the study.Antibiotic resistance and related molecular characteristics of HP,and CYP2C19 polymorphisms in the patients were detected by diffusion drug suscept-ibility testing,drug resistance gene testing,and next-generation sequencing,respectively.Results:Among the six antibiotics assessed,the resistance rate and the prevalence of resistance genes(rdxA)were highest for metronidazole(92.00%and 86.12%,respectively),and lowest for amoxicillin(Pbp1)(11.78%and 37.11%,respectively).The prevalence of CYP2C19 alleles showed that 46.77%,44.58%,and 8.65%of par-ticipants were fast,medium,and slow metabolizers,respectively.Of the participants,148(18.55%)had immunohistochemical sphericity.The eradication rate of HP lower using conventional treatment regimens than that using personalized treatment regimens(χ2=8.627,P=0.003).The HP eradication rate was higher among patients with a first diagnosis of drug resistancebased on molecular testing,than that in patients undergoing retreatment(χ2=6.242,P=0.012).Conclusions:The prevalence of amoxicillin-resistant HP is low in Wuwei City,which has a high incidence of gastric cancer.Molecular diagnosis of antimicrobial resistance could improve the HP eradication rate and provide a refer-ence for rational use of antibiotics in clinical practice.

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 investigate the incidence of venous thromboembolism (VTE) in patients with esophageal cancer (EC).Methods:The retrospective cohort study was conducted. The clinicopathological data of 8 458 EC patients who were admitted to Sichuan Cancer Hospital from January 2017 to December 2021 were collected. There were 6 923 males and 1 535 females, aged (64±9)years. There were 3 187 patients undergoing surgical treatment, and 5 271 cases undergoing non-surgical treatment. Observation indicators: (1) incidence of VTE in EC patients; (2) treatment and outcomes of patients with VTE. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Measurement data with skewed distribution were represented as M(range), and comparison between groups was analyzed using the nonparameter rank sum test. Count data were expressed as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Comparison of ordinal data was analyzed using the nonparameter rank sum test. Results:(1) Incidence of VTE in EC patients. Of 8 458 EC patients, 175 cases developed VTE, with an incidence rate of 2.069%(175/8 458). Among 175 VTE patients, there were 164 cases of deep venous thrombosis (DVT), 4 cases of pulmonary embolism (PE), 7 cases of DVT and PE. There were 59 surgical patients and 116 non-surgical patients. There was no significant difference in thrombus type between surgical and non-surgical EC patients with VTE ( χ2=1.95, P>0.05). Of 3 187 surgical patients, the incidence of VTE was 1.851%(59/3 187), including an incidence of 0.157%(5/3 187) of PE. PE accounted for 8.475%(5/59) of surgical patients with VTE. Of 5 271 non-surgical patients, the incidence of VTE was 2.201%(116/5 271), including an incidence of 0.114%(6/5 271) of PE. PE accounted for 5.172%(6/116) of non-surgical patients with VTE. There was no significant difference in the incidence of VTE or PE between surgical patients and non-surgical patients ( χ2=1.20, 0.05, P>0.05). (2) Treatment and outcomes of patients with VTE. Among 175 EC patients with VTE, 163 cases underwent drug treatment, and 12 cases did not receive treatment. Among 163 cases with drug therapy, 158 cases underwent anticoagulant therapy, 5 cases were treated with thrombolysis. All the 163 patients were improved and discharged from hospital. Conclusions:The incidence of VTE in patients with EC is relatively low, as 2.069%. There is no significant difference in the incidence of VTE or thrombus type between surgical EC patients and non-surgical EC patients.

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 investigate the clinicopathological characteristics of early gastric cancer with mixed histological staging, and to analyze the prognostic effect of endoscopic submucosal dissection (ESD) for early gastric cancer.Methods:Clinical data of early gastric cancer patients treated with ESD in Gansu Wuwei Cancer Hospital from January 2011 to March 2020 were collected, and clinicopathological characteristics of patients with mixed-type early gastric cancer were analyzed by descriptive statistical methods. The clinical effects and influencing factors of ESD on early gastric cancer were analyzed by logistic regression. Kaplan-Meier was used to estimate the survival rate, and log-rank test was used to compare the survival rate.Results:A total of 269 patients (280 lesions) were included in this study, including 216 males (80.30%) and 53 females (19.70%), with age of 60.43±8.01 years. There were 25 lesions (8.93%) of mixed early gastric cancer, 248 lesions (88.57%) of differentiated early gastric cancer, and 7 lesions (2.50%) of undifferentiated early gastric cancer. Compared with differentiated and undifferentiated early gastric cancer, the lesion site of mixed early gastric cancer was mainly located in the upper 1/3 of the stomach [64.00% (16/25), 40.73% (101/248) VS 0.00% (0/7), χ2=10.211, P=0.006], the proportion of the lesion size ≤2 cm was relatively small [52.00% (13/25), 80.65% (200/248) VS 85.71% (6/7), χ2=11.173, P=0.004], and the proportion of infiltration depth in the mucosa was lower [52.00% (13/25), 85.48% (212/248) VS 57.14% (4/7), χ2=20.019, P<0.001], the proportion of positive vertical resection margin was relatively high [20.00% (5/25), 2.82% (7/248) VS 0.00% (0/7), χ2=16.657, P<0.001], the proportion of vascular invasion was higher than that of differentiated carcinoma but lower than that of undifferentiated carcinoma [36.00% (9/25), 2.42% (6/248) VS 42.86% (3/7), χ2=58.413, P<0.001], the complete resection rate was lower [76.00% (19/25), 93.15% (231/248) VS 100.00% (7/7), χ2=9.497, P=0.009], the curative resection rate was lower than that of differentiated early gastric cancer, but higher than that of undifferentiated early gastric cancer [48.00% (12/25), 89.52% (222/248) VS 42.86% (3/7), χ2=39.757, P<0.001], and the proportion of eCura grade C2 was higher than that of differentiated cancer, but lower than that of undifferentiated cancer [48.00% (12/25), 5.65% (14/248) VS 57.14% (4/7), χ2=58.766, P<0.001]. The results of multivariate analysis showed that the larger lesions ( P=0.004, OR=0.539, 95% CI: 0.354-0.822) was the risk factor for curative resection. In terms of infiltration depth, mucosal ( P=0.001, OR=51.799, 95% CI: 5.535-84.768) and submucosal 1 ( P<0.001, OR=29.301, 95% CI: 24.694-73.972) were protective factors for curative resection compared with submucosal 2. In terms of differentiation degree, compared with mixed type, differentiated type ( P=0.024, OR=3.947, 95% CI: 1.195-13.032) was the protective factor for curative resection, while undifferentiated type ( P=0.443, OR=0.424, 95% CI: 0.048-3.788) showed no difference between curative resection and mixed type. During the follow-up, 7 patients died. The overall survival time was 114.42±0.97 months, and the 5-year survival rate was 97.10%. There was no significant difference in the survival rate of early gastric cancer patients with different degrees of differentiation ( χ2=0.434, P=0.805). The survival rate of early gastric cancer patients with or without curative resection was significantly different ( χ2=4.081, P=0.043). Conclusion:Mixed early gastric cancer patients show high margin positive rate, vascular infiltration, and less curative resection than differentiated early gastric cancer. Therefore, the process of treating mixed early gastric cancer should be more rigorous. The long-term survival prognosis of early gastric cancer after ESD treatment is promising.

The extensive research and application of human gene editing technology have raised many ethical issues,sparking heated debates among scholars.These debates mainly manifest in three aspects,including the limitation of human autonomy in the future,the ambiguity of self-identity,and the intensification of life hierarchy.The root causes of these debates mainly lie in the complexity of the subject's ethical sense of responsibility in the subjective aspect,the negative effects of technology in the objective aspect,and the insufficient external regulations in the social aspect.These issues require the following measures to be taken to resolve,such as enhancing the sense of ethical responsibility of subject,strengthening the internal ethical supervision of human gene editing technology,and establishing an ethical supervision committee and a unified ethical governance framework.