Transmission X-ray tubes are relatively new devices characterized by portability,suitability for miniaturization,and low requirements for shielding,making them ideal radiation sources for kilovoltage X-ray therapy.However,their application in radiotherapy remains underexplored.An electron target model of a transmission X-ray tube is developed using the Monte Carlo toolkit TOPAS 3.8.1.The study investigates the effect of tungsten target thickness on X-ray output efficiency,finding that a tube voltage of 50 kV and a tungsten thickness of 1.4 μm yields the highest emission efficiency.Based on the energy spectrum at this optimal efficiency,polynomial fitting approach is applied to determine the corresponding aluminum filter thickness for mean energies ranging from 20 keV to 35 keV,achieving a mean fitting error of 0.91%.Next,the study simulates dose deposition in a water phantom for spectra with different mean energies and various source-to-surface distances,and plots percent-depth-dose curves,relative normalized dose-depth curves,and relative normalized dose histograms under each treatment condition.Finally,the simulated results are compared with experimental data from the intraoperative radiotherapy system Intrabeam and the superficial X-ray therapy unit SRT-100,obtaining average relative errors of 3.71%and 4.38%,respectively.These findings provide a theoretical foundation for further optimization of transmission X-ray tubes in kilovoltage radiotherapy.

Objective:To explore the dosimetry optimization strategy based on filter thickness and shape selection for the bulb superficial X-ray radiotherapy unit.Methods:Monte Carlo code TOPAS was used to model tubular equipment, and the dose distribution from six X-ray energies (50-150 kV) and five conventional aluminum filters (0.5-3.0 mm) with different thickness were simulated in the water model. The percentage depth dose (PDD) curve along the central axis, the center-axis profile dose at different depths, and the lateral dose distribution were analyzed. The dose distribution of three different designs of aluminum filters (conventional cylindrical, conical and oblique cylindrical filters) was compared to evaluate the effect of dosimetric optimization of different filter shapes.Results:Under the same energy, increasing the thickness of the filter can optimize the superficial skin dose, and the optimization effect of depth dose uniformity can be increased by 26% at a depth of 5.5 mm at 70 kV energy. The raised, flat and inclined dose distribution modes can be achieved by using conventional cylindrical, conical and inclined aluminum filters.Conclusions:By selecting the appropriate X-ray energy and filter thickness, an ideal dose distribution matching the tumor depth can be achieved. The application of personalized filters is also of great significance for diverse target areas.

Transmission X-ray tubes are relatively new devices characterized by portability,suitability for miniaturization,and low requirements for shielding,making them ideal radiation sources for kilovoltage X-ray therapy.However,their application in radiotherapy remains underexplored.An electron target model of a transmission X-ray tube is developed using the Monte Carlo toolkit TOPAS 3.8.1.The study investigates the effect of tungsten target thickness on X-ray output efficiency,finding that a tube voltage of 50 kV and a tungsten thickness of 1.4 μm yields the highest emission efficiency.Based on the energy spectrum at this optimal efficiency,polynomial fitting approach is applied to determine the corresponding aluminum filter thickness for mean energies ranging from 20 keV to 35 keV,achieving a mean fitting error of 0.91%.Next,the study simulates dose deposition in a water phantom for spectra with different mean energies and various source-to-surface distances,and plots percent-depth-dose curves,relative normalized dose-depth curves,and relative normalized dose histograms under each treatment condition.Finally,the simulated results are compared with experimental data from the intraoperative radiotherapy system Intrabeam and the superficial X-ray therapy unit SRT-100,obtaining average relative errors of 3.71%and 4.38%,respectively.These findings provide a theoretical foundation for further optimization of transmission X-ray tubes in kilovoltage radiotherapy.

Objective:To explore the dosimetry optimization strategy based on filter thickness and shape selection for the bulb superficial X-ray radiotherapy unit.Methods:Monte Carlo code TOPAS was used to model tubular equipment, and the dose distribution from six X-ray energies (50-150 kV) and five conventional aluminum filters (0.5-3.0 mm) with different thickness were simulated in the water model. The percentage depth dose (PDD) curve along the central axis, the center-axis profile dose at different depths, and the lateral dose distribution were analyzed. The dose distribution of three different designs of aluminum filters (conventional cylindrical, conical and oblique cylindrical filters) was compared to evaluate the effect of dosimetric optimization of different filter shapes.Results:Under the same energy, increasing the thickness of the filter can optimize the superficial skin dose, and the optimization effect of depth dose uniformity can be increased by 26% at a depth of 5.5 mm at 70 kV energy. The raised, flat and inclined dose distribution modes can be achieved by using conventional cylindrical, conical and inclined aluminum filters.Conclusions:By selecting the appropriate X-ray energy and filter thickness, an ideal dose distribution matching the tumor depth can be achieved. The application of personalized filters is also of great significance for diverse target areas.

Objective:To investigate and compare the clinical outcomes of the arterial pre-occlusion technique(APOT) and the traditional technique in the surgery of locally advanced pancreatic cancer with arterial involvement after conversion therapy.Methods:This is a retrospective cohort study. The clinical data of 145 patients with locally advanced pancreatic cancer with arterial involvement admitted to the Department of Hepato-Biliary-Pancreatic Surgery of the First Hospital Affiliated to Naval Medical University,from January 2020 to December 2022 were retrospectively analyzed. All patients completed neoadjuvant therapy for tumors, and the feasibility of radical surgical treatment was determined by a multidisciplinary collaborative team evaluation before surgery. According to whether the intraoperative artery was pre-occluded, 145 patients were divided into two groups, including 28 cases in the APOT group(16 males, 12 females, aged (59.0±9.4) years), and 117 cases in the routine surgery group(76 males, 41 females, aged (55.1±8.2) years). To ensure comparability of baseline data between the APOT group and the routine surgery group, a 1∶2 match was performed using the propensity score matching method, and the caliper value was 0.006 45. The t-test,the Mann-Whitney U test, χ2 test or Fisher′s exact test were used to compare the data between the two groups,respectively. Results:After matching the propensity score,there were 28 cases in the APOT group and 56 cases in the routine surgery group. There were no significant differences in gender,age,preoperative comorbidities,preoperative body mass index,surgical approaches,chemotherapy regimen,stereotactic body radiation therapy ratio,tumor markers,and type of invaded artery between the two groups (all P>0.05).The arterial occlusion time M(IQR) in the APOT group was 7.0(3.8)minutes(range:3 to 15 minutes),and no ischemic manifestations were observed in the distal target organs that blocked blood vessels after surgery. The operation time was (170.3±57.7)minutes in the APOT group and (235.0±80.2)minutes in the routine surgery group,and the difference was statistically significant ( t=-3.800, P<0.01). The APOT group also experienced less intraoperative blood loss(650(588)ml vs. 800(600)ml; U=1 026.500, P=0.021). No significant differences were found between the groups in combined vein resection and reconstruction,celiac trunk resection,early postoperative complications, readmission rates at 30 days,and postoperative length of stay(all P>0.05). Extra-arterial dissection was performed in all patients,with arterial resection and reconstruction in 3 cases: 2 cases in the APOT group(1 case involving the superior mesenteric artery and 1 case involving the common hepatic artery) and 1 case in the routine group(involving the common hepatic artery). Postoperative abdominal bleeding occurred in 4 cases,with 3 cases in the routine group,1 case in the routine group. The R0 resection rate was 85.7%(24/28) in the APOT group and 80.4%(45/56) in the routine group,without significant differences between the groups( P=0.763). The median overall survival time was 27.6 months for the APOT group and 22.5 months for the routine group,while the median disease-free survival was 11.7 months and 16.8 months,respectively,with no significant differences between the two groups( P=0.532, P=0.927). Conclusion:The arterial pre-occlusion technique can be used for extra-arterial dissection in patients with locally advanced pancreatic cancer involving the arteries,reducing surgery time and intraoperative blood loss.

Objective:To investigate and compare the clinical outcomes of the arterial pre-occlusion technique(APOT) and the traditional technique in the surgery of locally advanced pancreatic cancer with arterial involvement after conversion therapy.Methods:This is a retrospective cohort study. The clinical data of 145 patients with locally advanced pancreatic cancer with arterial involvement admitted to the Department of Hepato-Biliary-Pancreatic Surgery of the First Hospital Affiliated to Naval Medical University,from January 2020 to December 2022 were retrospectively analyzed. All patients completed neoadjuvant therapy for tumors, and the feasibility of radical surgical treatment was determined by a multidisciplinary collaborative team evaluation before surgery. According to whether the intraoperative artery was pre-occluded, 145 patients were divided into two groups, including 28 cases in the APOT group(16 males, 12 females, aged (59.0±9.4) years), and 117 cases in the routine surgery group(76 males, 41 females, aged (55.1±8.2) years). To ensure comparability of baseline data between the APOT group and the routine surgery group, a 1∶2 match was performed using the propensity score matching method, and the caliper value was 0.006 45. The t-test,the Mann-Whitney U test, χ2 test or Fisher′s exact test were used to compare the data between the two groups,respectively. Results:After matching the propensity score,there were 28 cases in the APOT group and 56 cases in the routine surgery group. There were no significant differences in gender,age,preoperative comorbidities,preoperative body mass index,surgical approaches,chemotherapy regimen,stereotactic body radiation therapy ratio,tumor markers,and type of invaded artery between the two groups (all P>0.05).The arterial occlusion time M(IQR) in the APOT group was 7.0(3.8)minutes(range:3 to 15 minutes),and no ischemic manifestations were observed in the distal target organs that blocked blood vessels after surgery. The operation time was (170.3±57.7)minutes in the APOT group and (235.0±80.2)minutes in the routine surgery group,and the difference was statistically significant ( t=-3.800, P<0.01). The APOT group also experienced less intraoperative blood loss(650(588)ml vs. 800(600)ml; U=1 026.500, P=0.021). No significant differences were found between the groups in combined vein resection and reconstruction,celiac trunk resection,early postoperative complications, readmission rates at 30 days,and postoperative length of stay(all P>0.05). Extra-arterial dissection was performed in all patients,with arterial resection and reconstruction in 3 cases: 2 cases in the APOT group(1 case involving the superior mesenteric artery and 1 case involving the common hepatic artery) and 1 case in the routine group(involving the common hepatic artery). Postoperative abdominal bleeding occurred in 4 cases,with 3 cases in the routine group,1 case in the routine group. The R0 resection rate was 85.7%(24/28) in the APOT group and 80.4%(45/56) in the routine group,without significant differences between the groups( P=0.763). The median overall survival time was 27.6 months for the APOT group and 22.5 months for the routine group,while the median disease-free survival was 11.7 months and 16.8 months,respectively,with no significant differences between the two groups( P=0.532, P=0.927). Conclusion:The arterial pre-occlusion technique can be used for extra-arterial dissection in patients with locally advanced pancreatic cancer involving the arteries,reducing surgery time and intraoperative blood loss.

Objective To evaluate the performance of magnetic resonance imaging(MRI)multi-sequence feature imputation and fusion mutual model based on sequence deletion in differentiating high-grade glioma(HGG)from low-grade glioma(LGG).Methods We retrospectively collected multi-sequence MR images from 305 glioma patients,including 189 HGG patients and 116 LGG patients.The region of interest(ROI)of T1-weighted images(T1WI),T2-weighted images(T2WI),T2 fluid attenuated inversion recovery(T2_FLAIR)and post-contrast enhancement T1WI(CE_T1WI)were delineated to extract the radiomics features.A mutual-aid model of MRI multi-sequence feature imputation and fusion based on sequence deletion was used for imputation and fusion of the feature matrix with missing data.The discriminative ability of the model was evaluated using 5-fold cross-validation method and by assessing the accuracy,balanced accuracy,area under the ROC curve(AUC),specificity,and sensitivity.The proposed model was quantitatively compared with other non-holonomic multimodal classification models for discriminating HGG and LGG.Class separability experiments were performed on the latent features learned by the proposed feature imputation and fusion methods to observe the classification effect of the samples in two-dimensional plane.Convergence experiments were used to verify the feasibility of the model.Results For differentiation of HGG from LGG with a missing rate of 10%,the proposed model achieved accuracy,balanced accuracy,AUC,specificity,and sensitivity of 0.777,0.768,0.826,0.754 and 0.780,respectively.The fused latent features showed excellent performance in the class separability experiment,and the algorithm could be iterated to convergence with superior classification performance over other methods at the missing rates of 30%and 50%.Conclusion The proposed model has excellent performance in classification task of HGG and LGG and outperforms other non-holonomic multimodal classification models,demonstrating its potential for efficient processing of non-holonomic multimodal data.

ObjectiveTo investigate the change and potential role of Mindin protein in the treatment of chronic hepatitis B （CHB） with PEG-IFNα-2b. MethodsA total of 29 CHB patients who received the treatment with PEG-IFNα-2b in The Second Affiliated Hospital of Xi’an Jiaotong University from January 2018 to December 2019 were enrolled， and according to their clinical outcome， they were divided into cured group with 17 patients and uncured group with 12 patients. Peripheral blood samples were collected from both groups at baseline， 12 weeks， and 24 weeks to measure blood routine indices， liver function parameters， hepatitis B markers， and Mindin protein. HBsAg， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， and Mindin protein at different time points were compared between the two groups. The independent-samples t test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； a Spearman correlation analysis was used to investigate correlation； a multiple linear regression analysis was used to investigate the influence of HBsAg and ALT on the content of Mindin protein. ResultsThe analysis of baseline data showed that there were significant differences in the levels of HBsAg， HBeAb， albumin， and albumin/globulin ratio between the cured group and the uncured group （all P<0.05）. The cured group tended to have a gradual increase in the level of Mindin， and the level of Mindin at 24 weeks was significantly higher than that at baseline （P<0.05）. The cured group had a significantly higher level of Mindin protein than the uncured group at 24 weeks （P=0.019）. The cured group had a significantly lower level of HBsAg than the uncured group （P<0.05）， with a significant change from baseline to each time point within the cured group （P<0.05）. In addition， the levels of ALT and AST in the cured group tended to first increase and then decrease， and the expression levels at 12 weeks were significantly higher than those at baseline （P<0.05）. At 12 weeks， there was a strong linear correlation between Mindin protein levels and ALT in the untreated group （r=0.760 8， P<0.05）， and further multiple linear regression analysis also demonstrated a linear relationship between the two （b=1.571， P=0.019）. ConclusionThere is a significant difference in the level of Mindin protein between the cured group and the non-cured group after 24 weeks of PEG-IFNα-2b antiviral treatment， and therefore， detecting the dynamic changes of Mindin protein can better predict the treatment outcome of CHB， which provides a reference for clinical practice.

Objective To evaluate the performance of magnetic resonance imaging(MRI)multi-sequence feature imputation and fusion mutual model based on sequence deletion in differentiating high-grade glioma(HGG)from low-grade glioma(LGG).Methods We retrospectively collected multi-sequence MR images from 305 glioma patients,including 189 HGG patients and 116 LGG patients.The region of interest(ROI)of T1-weighted images(T1WI),T2-weighted images(T2WI),T2 fluid attenuated inversion recovery(T2_FLAIR)and post-contrast enhancement T1WI(CE_T1WI)were delineated to extract the radiomics features.A mutual-aid model of MRI multi-sequence feature imputation and fusion based on sequence deletion was used for imputation and fusion of the feature matrix with missing data.The discriminative ability of the model was evaluated using 5-fold cross-validation method and by assessing the accuracy,balanced accuracy,area under the ROC curve(AUC),specificity,and sensitivity.The proposed model was quantitatively compared with other non-holonomic multimodal classification models for discriminating HGG and LGG.Class separability experiments were performed on the latent features learned by the proposed feature imputation and fusion methods to observe the classification effect of the samples in two-dimensional plane.Convergence experiments were used to verify the feasibility of the model.Results For differentiation of HGG from LGG with a missing rate of 10%,the proposed model achieved accuracy,balanced accuracy,AUC,specificity,and sensitivity of 0.777,0.768,0.826,0.754 and 0.780,respectively.The fused latent features showed excellent performance in the class separability experiment,and the algorithm could be iterated to convergence with superior classification performance over other methods at the missing rates of 30%and 50%.Conclusion The proposed model has excellent performance in classification task of HGG and LGG and outperforms other non-holonomic multimodal classification models,demonstrating its potential for efficient processing of non-holonomic multimodal data.

Objective In order to explore the influence and effect of case teaching method based on real patients in oto-rhinolaryngology on clinical practice ability of general practice.Methods 96 trainees of general practice in otolaryngology de-partment from January 2018 to January 2021 were randomly divided into two groups:a CBL group and a control group.In the CBL group,CBL teaching method was adopted based on real patients in Otorhinolaryngology.Conventional teaching method was used in the control group.Results The theoretical scores of written test and the examination of clinical skill operation scores of the CBL group and the control group were analyzed.There was significant difference between the two groups(P＜0.05).The students in CBL group were more satisfied with clinical thinking ability,analysis and problem solving ability,active learning abil-ity,learning efficiency,teacher-student interaction,doctor-patient communication ability and consultation skills than the control group.There was significant difference between the two groups(P＜0.05).Conclusion The CBL teaching method can obvi-ously improve the learning enthusiasm and clinical practice ability of general resident training doctors.The teaching quality has been significantly improved.It is of great value to cultivate excellent general practitioners.