A dose reconstruction algorithm for electrionic portal imaging device(EPID)based on calibration and calculation is developed.The raw data of EPID in continuous acquisition mode are corrected for dark field and gain,and the gray level features of bright field are used to determine the field boundary.Subsequently,MU calibration,off-axis calibration and field size calibration are performed on the EPID data,and dose reconstruction is carried out based on the calibrated superimposed flux and the Monte Carlo model of the linac head.Nine cases of IMRT plans are selected for verification and measurement using EPID and MapCheck separately,and the passing rates between the two tools are compared under different gamma criteria(3%/3 mm and 2%/2 mm).For a planned case,the average passing rates of multiple cases verified by MapCheck under the two criteria were 99.02%±1.28%and 90.84%±4.49%,and the average passing rates of the EPID reconstruction models were 98.86%±1.19%and 91.39%±4.80%.Compared with MapCheck,the EPID reconstruction algorithm based on calibration and calculation has no significant difference in the passing rate of IMRT plan verification(P＞0.05),which meets the clinical requirements of dose verification.

Objective:To review the clinical status based on the best evidence of drug administration in patients with dysphagia, systematically analyze the obstacle factors and promoting factors in the process of evidence transformation, and formulate reform strategies.Methods:Based on the evidence-based nursing research method and the guidance of the Ottawa Model of Research Use (OMRU), the review indicators were developed based on the best evidence. The current status of clinical practice behaviors of 223 patients and 75 nurses in the Neurology, Neurosurgery and Geriatric departments of the Affiliated Hospital of Jiangsu University were reviewed from July to December 2021.Based on the results of the review, qualitative interviews were conducted with 32 potential adopters, and content analysis was used to assess the barriers and contributing factors to the clinical translation of evidence in three aspects: evidence-based change, potential adopters and practice environment, so as to develop effective strategies.Results:Based on the 22 best evidence selected, the evidence-based team developed 25 review indicators to carry out clinical review, showing that the compliance rate of 16 indicators were less than 60%. By analyzing and summarizing the interview results of potential adopters, the main obstacles leading to the low compliance rate of nurses were analyzed as follows: evidence-based reform changed the traditional work mode, and the application of evidence was not convenient; at the level of potential adopters, nurses had poor knowledge and practice, heavy work burden, and low awareness of patients and caregivers; at the level of practice environment, there was lack of nursing norms and procedures for clinical transformation of evidence, and the channels of multi-disciplinary collaboration and communication were not smooth. The main promoting factors were the perfect supervision mechanism of evidence-based nursing projects, the evidence-based group had rich experience in evidence transformation, the management was willing to change, and the practitioners were good at innovation.Conclusions:There is still a large gap between the clinical practice and the best evidence of drug administration in patients with dysphagia. The promoting factors should be fully utilized to overcome the obstacles and implement improvements to promote the effective transformation of evidence into clinical practice.

Objective To develop nurses'knowledge,attitude and practice questionnaire on medication management for patients with dysphagia,and test its reliability and validity.Methods Based on the evidence-based summary of the best evidence of medication management for patients with dysphagia,guided by the the-ory of knowledge,attitude and practice,the basic dimensions and item pool of the questionnaire were deter-mined through group discussion,Delphi expert consultation and pre-investigation.In order to revise the ques-tionnaire,437 nurses from 10 tertiary hospitals in Jiangsu Province were conveniently selected for investigation,and the reliability and validity of the questionnaire were tested according to the survey results.Results The nurses'knowl-edge,attitude and practice questionnaire on medication management for patients with dysphagia included 43 items in three dimensions.The three dimensions were analyzed by exploratory factors,and six common factors with characteristic roots>1 were extracted.Two factors were extracted from the knowledge dimension,and the cumulative variance contribution rate was 74.958%,One factor was extracted from the attitude dimen-sion,and the cumulative variance contribution rate was 77.655%.Three factors were extracted from the prac-tice dimension,and the cumulative variance contribution rate was 72.274%.The factor load of each item was 0.618-0.902,Cronbach's α coefficient of the total questionnaire was 0.949,and the test-retest reliability was 0.909.The overall content validity coefficient of the questionnaire was 0.922,and the content validity coeffi-cient for each item was 0.800-1.000.Conclusion The nurses'knowledge,attitude and practice questionnaire on medication management for patients with dysphagia developed in this study has good reliability and validi-ty,and could be used as an effective tool to evaluate the status quo of nurses'medication management for pa-tients with dysphagia.

Objective A quality control(QC)system based on the electronic portal imaging device(EPID)system was used to realize the Multi-Leaf Collimator(MLC)position verification and dose verification functions on Primus and VenusX accelerators.Methods The MLC positions were calculated by the maximum gradient method of gray values to evaluate the deviation.The dose of images acquired by EPID were reconstructed using the algorithm combining dose calibration and dose calculation.The dose data obtained by EPID and two-dimensional matrix(MapCheck/PTW)were compared with the dose calculated by Pinnacle/TiGRT TPS for γ passing rate analysis.Results The position error of VenusX MLC was less than 1 mm.The position error of Primus MLC was significantly reduced after being recalibrated under the instructions of EPID.For the dose reconstructed by EPID,the average γ passing rates of Primus were 98.86%and 91.39%under the criteria of 3%/3 mm,10%threshold and 2%/2 mm,10%threshold,respectively.The average γ passing rates of VenusX were 98.49%and 91.11%,respectively.Conclusion The EPID-based accelerator quality control system can improve the efficiency of accelerator quality control and reduce the workload of physicists.

Objective To investigate the clinicopathological features,immunophenotypes,molecular genetic alterations,and prognosis of succinate dehydrogenase-deficient renal cell carcinoma(SDH-RCC).Methods A total of 11 cases of SDH-RCC diagnosed at West China Hospital,Sichuan University between 2016 and 2023 were selected for clinicopathological,immunohistochemical,and DNA sequencing analyses.Results Among the 11 cases of SDH-RCC,there were 5 male patients and 6 female patients.The patients'ages ranged from 12 to 71 years,with an average age of 39.7 years.Among them,5 patients had tumors located in the right kidney,5 had tumors located in the left kidney,and 1 patient had bilateral tumors.Microscopic observation showed that the tumor cells of the SDH-RCC patients displayed a wide spectrum of structures,forming sheet-like,nested,and glandular structures.In addition,tumor cells in papillary structures were observed in some cases.The tumor cells had abundant cytoplasm,was eosinophilic,and contained flocculent materials.Intracytoplasmic vacuolations were observed in some of the cells.Among all the patients,7(7/11,63.6％)showed typical low-grade features(grade 1-2 according to the International Society of Urological Pathology[ISUPJ/WHO 2016 classification),and 4(4/11,36.4％)showed high-grade features(grade 3 according to the ISUP/WHO 2016 classification).The average ages of patients with low-grade and high-grade features were 32.1 years and 58.0 years,respectively.Immunohistochemical staining of all 11 cases demonstrated negative results for SDHB and cytokeratin 7(CK7),and positive staining results for paired box 8(PAX-8),fumarate hydratase(FH),and epithelial membrane antigen(EMA).Their Ki-67 index was l％-30％.In one case,the loss of SDHB expression was also accompanied by a loss of SDHA expression.Sanger sequencing was performed to examine all the exons of SDHB in 7 cases.One case showed a frameshift mutation,c.236Tdel(p.K80Rfs*),and another case harbored a missense mutation,c.725G＞A(p.Arg242His).In another case,next generation sequencing revealed that large fragments of SDHB(Exon 4-8 del)were missing.Follow-up data were available for 10 patients.The follow-up time ranged from 4 to 138 months,with the average being 32.8 months,and all patients survived.Metastasis and recurrence were reported in 5 cases,with 3 of them showing high-grade features and 2 showing low-grade features.Conclusion SDH-RCC is rare and the patients demonstrate a relatively young age of onsets.Patients may present with bilateral tumors.Tumors with low-grade features usually occur in young patients,with their Ki-67 index usually being lower than 5％.Individual cases may experience tumor recurrence and metastasis over a long period of follow-up.Tumors with high-grade features tend to occur in older patients who have a higher Ki-67 index,and who are prone to recurrence and metastasis.Negative immunohistochemical staining results for SDHB can assist in tumor diagnosis,but the loss of SDHB protein expression does not necessarily lead to the detection of SDHB gene mutation.

Objective:To construct a cycle dual-task network based on cycleGAN to implement 3D CT synthesis from single-view projection for adaptive radiotherapy of thoracic tumor and then evaluate image quality and dose accuracy.Methods:A total of 45 thoracic tumor patients admitted to the Affiliated Changzhou No.2 People's Hospital of Nanjing Medical University were collected, and 991 cases were also selected from public dataset as pretrained dataset. Multi-view projections were acquired by ASTRA algorithm. The public dataset was divided into a training set of 800 cases, a validation set of 160 cases and a test set of 31 cases. The dataset obtained from patients in our hospital was divided into a training set of 40 cases and a test set of 5 cases. The network included synthetic CT model and multi-view projection prediction model and achieved the dual-task training. The final test only used the synthetic CT model to acquire the predicted CT images and deliver image quality [mean absolute error (MAE), peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM)] and dose evaluation.Results:Image quality evaluation metrics for synthetic CT showed high image synthesis accuracy with MAE of 0.05±0.01, PSNR of 19.08±1.69, SSIM of 0.75±0.04, respectively. The dose distribution calculated on synthetic CT was also close to the actual dose distribution. The mean 3%/3 mm γ pass rate for synthetic CT was 93.1%.Conclusions:A dual-task cycle network modified on cycleGAN has been implemented to rapidly and accurately predict 3D CT from single-view projection, which can be applied to the workflow of adaptive radiotherapy for thoracic cancer. Both image generation quality and dosimetric evaluation demonstrate that synthetic CT can meet the clinical requirements for radiotherapy.

Objective:To develop the real-time radiotherapy monitoring system of three-dimensional (3D) point cloud by using depth camera and verify its feasibility.Methods:Taking the depth camera coordinate system as the world coordinate system, the conversion relationship between the simulation CT coordinate system and the world coordinate system was obtained from the calibration module. The patient's simulation CT point cloud was transformed into the world coordinate system through the above relationship, and registered with the patient's surface point cloud obtained in real-time manner by the depth camera to calculate the six-dimensional (6D) error, and complete the positioning verification and fractional internal position error monitoring in radiotherapy. Mean and standard deviation of 6D calculation error, Hausdorff distance of point cloud after registration and the running time of each part of the program were calculated to verify the feasibility of the system. Fifteen real patients were selected to calculate the 6D error between the system and cone beam CT (CBCT).Results:In the phantom experiment, the errors of the system in the x, y and z axes were (1.292±0.880)mm, (1.963±1.115)mm, (1.496±1.045)mm, respectively, and the errors in the rotation, pitch and roll directions were 0.201°±0.181°, 0.286°±0.326°, 0.181°±0.192°, respectively. For real patients, the translational error of the system was within 2.6 mm, the rotational error was approximately 1°, and the program run at 1-2 frames/s. The precision and speed met the radiotherapy requirement. Conclusion:The 3D point cloud radiotherapy real-time monitoring system based on depth camera can automatically complete the positioning verification before radiotherapy, real-time monitoring of body position during radiotherapy, and provide error visual feedback, which has potential clinical application value.

Objective To investigate the dosimetric effect of truncated regions in computed tomography (CT) images on the targets and organs at risk in volumetric modulated arc therapy (VMAT) for middle thoracic esophageal cancer. Methods CT images of 15 patients with middle thoracic esophageal cancer were selected. Circle masks were used to make the volume of the truncated region account for 10%, 20%, 30%, and 40% of the arm volume, and the corresponding truncated CT images were obtained. The real CT was denoted as CT0. Two radiotherapy plans were made on CT0. One plan was VMAT_1F with full arcs, and the other one was VMAT_3F with arm avoidance. The plans were transplanted to four truncated CT, respectively, and the dosimetric differences between different plans were compared using Wilcoxon signed-rank test. Results Compared with VMAT_1F in CT0, D_mean and V₅ of the lung decreased in VMAT_3F, but D_max of the spinal cord, D_mean of the heart, and V₂₀ of the lung increased. In VMAT_3F, there was no statistically significant difference between the dosimetric parameters in the four truncated CT and those in CT0 (all P > 0.05). In VMAT_1F, except for homogeneity index and D_max of the spinal cord, the dosimetric parameters in four truncated CT were significantly different from those in CT0 (P < 0.05). The dosimetric difference increased with the increase in truncated region-to-volume ratio. Conclusion Complete CT data should be collected in clinical practice, and the radiation field avoiding the truncated regionshould be set if necessary to reduce the influence of the truncated region on dosimetry.

Objective : To evaluate the effects of low temperature plasma modification on the surface morphology and bonding durability of zirconia ceramics. Methods: 180 pieces of zirconia ceramic(Y-TZP) were randomly divided into 5 groups(n= 36). Group A:blank group; Group B:sandblast group; Group C:nitrogen( N2) plasma group; Group D:oxygen(O2) plasma group; Group E:argon(Ar) plasma group. The surface hydrophilicity and microstructure of zirconia ceramics were observed,and the changes of surface elements and functional groups were detected. Each group of bonded specimens was randomly divided into two subgroups(n= 15). After receiving 0 and10 000 cycles of heat and cold,the shear strength was measured. The measured results were statistically analyzed and the fracture mode was analyzed. Results: The surface contact angles of groups B,C,D and E were significantly lower than those of group A,with statistically significant differences(P<0. 001). Compared with group A,the surface morphology of group C,D and E did not significantly change,while that of group B significantly changed. XPS showed that the surface carbon decreased,oxygen increased and carbon/oxygen ratio decreased after plasma treatment. SBS results showed that the immediate shear bonding strength of group A was lower than that of the other four groups(P<0. 001),and there was no significant difference in the immediate shear bonding strength of groups B,C,D and E(P>0. 05);After artificial aging,the shear bonding strength of group A was significantly lower than that of the other four groups,and the difference of shear bonding strength between groups A and B before and after artificial aging was statistically significant(P<0. 001). Conclusion The zirconia ceramics achieves better bonding strength and durability with resin cement through three kinds of low temperature plasmas,without changing the surface morphology.

Objective:To explore the protective effect of puerarin on hypoxia/reoxygenation (H/R)-induced acute kidney injury(AKI)in vitro.Methods:HK-2 cells were treated with H/R for simulating ischemia reperfusion injury(IRI)in vivo. The experimental groups included control group, H/R treatment group(0/6/12/24 h), H/R 24 h + puerarin treatment group(puerarin, Pue), H/R 24 h + Pue+ 3-methyladenine(3-MA)treatment group and H/R 24 h+ 3-MA treatment group. Immunoblotting was employed for detecting the expression changes of autophagy-related proteins, CCK-8 for examining cell proliferation, electron microscopy for observing autophagosome formation and TUNEL for detecting apoptosis.Results:As compared with control group, the expression of LC3-II rose in H/R 24 h group, the expression of autophagy marker P62 declined, count of autophagosome increased, cell viability decreased and cellular inflammation occurred. Puerarin had similar effects to 3-MA. As compared with H/R 24 h group, puerarin could reverse the changes in the expression levels of LC3 and P62 induced by H/R( P<0.05). There were greater cell viability, reduced autophagosome count and lessened cell apoptosis( P<0.05). At the same time, protein expression levels of HMGB1, TLR4 and NF-κB dropped( P<0.05). Conclusions:Puerarin suppresses autophagy through HMGB1/TLR4/NF-κB axis for lessening ischemia-reperfusion injury an in vitro model.