Objective To evaluate the feasibility and dosimetric features of a volume modulated arc therapy (VMAT)-configured model in knowledge-based optimization of fixed-field dynamic intensitymodulated radiotherapy (IMRT) plans based on the Varian RapidPlan system.Methods ① A dose-volume histogram prediction model was trained with 81 qualified preoperative VMAT plans for rectal cancer and then statistically verified.② For clinically approved 10 IMRT plans with the same dose prescription,the above model was used to automatically generate new optimization parameters and dynamic muhileaf collimator (MLC) sequences with field geometry and beam energy unchanged.③ In order to rule out the disparities between different versions,a single algorithm was used to calculate the absolute doses of the original and new plans.④ Statistical analyses were performed on dosimetric parameters after comparable target dose coverage was achieved in the two plans by appropriate normalization.Results On the basis of similar target dose homogeneity and coverage,RapidPlan significantly reduced the doses to the urinary bladder (D50％ by 9.01 Gy,P =0.000;Dmean by 8.08 Gy,P =0.005) and the femoral head (D50％ by 4.20 Gy,P =0.000;Dmean by 3.84 Gy,P=0.005) but significantly elevated the mean total number of monitor units (1211±99 vs.771±79,P=0.000) and the number of fields with multiple MLC carriage groups.The knowledge-based semi-automated optimization caused a significantly larger number of high-dose hotspots but a similar D2％ (52.54 vs.52.71 Gy,P=0.239).Conclusions The VMAT model can be used for the knowledge-based semi-automated optimization of IMRT plans to enhance the efficiency and OAR protection.However,the resulting high-dose hotspots need further manual intervention.

Objective To explore the Monte Carlo calculation methods for the absolute dose calibration and output factor of 6 MV flattening-filter ( FF) and flattening-filter free ( FFF) photon beams based on TrueBeam accelerator .Methods The BEAMnrc code was used to model the LINAC head of FF and FFF modes.The BEAM_up covers the components from the target to the monitor chamber , and BEAM_down includes the structures beneath the chamber , the dose deposit to the monitor chamber contributed by the incidence electrons and scattered particles from the secondary collimators were calculated respectively .The incidence electron-induced dose at certain depths on the central axis were simulated by means of the DOSXYZnrc code .By means of dose calibration equation , the calibration factor for the standard field (10 cm ×10 cm) and the output factors for various fields (1 cm ×1 cm-40 cm ×40 cm) were computed respectively .Results For the 6 MV FF and FFF beams under the standard 10 cm ×10 cm field, 1 MU equals to 7.747 ×1013 ±3.099 ×1011 and 3.248 ×1013 ±1.624 ×1011 electrons to the target , respectively , which deposited 21.53 and 35.01 cGy to the monitor chamber of the virtual accelerator respectively .The difference between the simulated and calculated output factors were 0.72%±1.4%and 0.56%±0.78%for FF and FFF , respectively .Conclusions The model generated and measured output factors agree well , indicating the good accuracy of the dose calculation by the model , which would provides basis for further clinical dosimetric studies .

Objective:To explore the cognition and use experience of residents based on technical acceptance model, and provide decision-making information and reference for the promotion and optimization construction of the smart ward.Methods:Based on the technical acceptance model, the research team made cognitive and experience evaluation questionnaire of hospitalization patients of the smart wards and evaluated its reliability. By adopting cross-sectional research methods, 368 patients who were hospitalized in the smart wards of the 10 leading clinical specialty in"136" Xingyi Project in Shanxi Province were selected as research objects from January to April 2022. The cognitive and experience evaluation questionnaire of hospitalization patients of the smart wards were used to conduct investigations and research.Results:Among 368 patients, male 148 cases, female 220 cases, aged 18 to 70 years old. The overall Cronbach α coefficient of the questionnaire was 0.887, which had a good degree of reliability. In the cognition and experience evaluation of the smart wards, the five dimensions of perception of usefulness, perception of ease of use, perception safety, attitude and willingness to use were (4.76 ± 0.38),(4.75 ± 0.46), (4.75 ± 0.46), (4.72 ± 0.19), (4.73 ± 0.55), (4.77 ± 0.27) points respectively, the proportion of "very agreed" was 80.16% (295/368); the overall satisfaction of the smart wards scored (4.76 ± 0.35) points, the proportion of "very satisfied" was 79.35% (292/368). Conclusions:The application of the smart ward in the nursing work of inpatients will help optimize the patients′ medical service experience and improve the satisfaction of hospitalization.

Objective:To construct the pET30a-EgG1Y162-2 prokaryotic expression plasmid and induce the expression of EgG1Y162-2 protein, so as to provide a research basis for development of Echinococcus granulosus vaccine. Methods:Using Echinococcus granulosus cDNA as a template, the target gene of EgG1Y162-2 was synthesized by PCR, and after digestion with restriction enzymes EcoRⅠ and Hind Ⅲ, it was connected to the prokaryotic expression vector pET30a to construct the recombinant plasmid pET30a-EgG1Y162-2. The recombinant plasmid was transformed into competent cell BL21 (DE3) and induced by isopropyl β-D-thiogalactoside (IPTG) to express a large number of proteins. The recombinant protein was purified by affinity chromatography. The purification level was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the expression product was identified by Western blotting. Results:The recombinant plasmid pET30a-EgG1Y162-2 was successfully constructed. After inducting expression, the bacterial supernatant and the eluate were both at a relative molecular weight of about 15 × 10 3, and the protein antigen component eluted with 200 mmol/L imidazole was relatively pure. Western blotting results showed that the purified recombinant protein EgG1Y162-2 with His tag could be recognized by His monoclonal antibody. Conclusion:The pET30a-EgG1Y162-2 prokaryotic expression plasmid of Echinococcus granulosus is successfully constructed, and the recombinant protein of EgG1Y162-2 is induced to express, laying a foundation for further study on anti- Echinococcus granulosus vaccine.

Objective:To explore the feasibility and optimization effect of modifying the Henry Ford Hospital (HFHS) RapidPlan model for stereotactic body radiation therapy planning based on local requirements.Methods:The following changes were made based on Henry Ford Health System(HFHS) Rapid Plan Lung SBRT model, taking the latest clinical guideline evidence and local clinical practice into account: Internal gross target volume(IGTV) and organ at risk(OAR) structure, lung, were added and set corresponding parameters.The upper value of planning target volume (PTV) was adjusted from 109% to 125%. The original training library was replaced with 73 local historical simultaneous integrated boosting plans, and statistical verification and outlier cleaning of the initial trained model were performed using Model Analytics software. Totally 10 cases not included in the model library were selected for independent verification, and automatic optimization result of the models before and after modifying were compared under the same beam condition. The following dosimetric parameters were compared after target dose normalization: conformal index (CI) of target volume, the mean doses, maximum doses and dose-volume parameters of OARs.Results:The " tail" of the PTV′s DVH and the " shoulder" and " tail" of the IGTV′s DVH of model M (local) validation plan (M (local)_P) performs higher than the original model HFHS (HFHS_P). The PTV_CI (1.07±0.13) of M local_P were significantly smaller than HFHS_P (1.25±0.24) ( Z=-2.497, P<0.05). Except for Heart_ D15 cm 3 and Heart_ Dmax, most of the M local_P dosimetric parameters of OARs were lower than HFHS_P, and the standard deviation was smaller. However, the difference of between two plans was no more than 3.06%. 10 HFHS_P plans don′t satisfy dose parameters requirement, two of which PTV_CI values are 1.52 and 1.74, far beyond the clinically acceptable range. Conclusions:Commercial model HFHS could be localized by replacing training library and adjusting parameters. Moreover, plans optimized by the modified model are local clinical acceptable in the aspects of target volume conformity and hotspots, and have a better performance in terms of OAR sparing and plan consistency.

Objective To compare two pretreatment plan QA methods for HalcyonTM accelerator using Portal Dosimetry (PD),and PTW OCTAVIUS 1500 detector array + Octagonal phantom (Oct 1500)respectively.Methods Parallel measurement-based pretreatment QA using two methods was performed for 22 IMRT/VMAT plans (74 fields) that have been used to treat 20 patients recruited in the Halcyon clinical trial.Several γ 2D comparisons were also applied to provide guidelines for Halcyon planning QA.Results Using Oct1500 method,the γ 2D passing rates for 74 fields in 22 Plans were 95.26±3.59,95.01±3.62 (Local Dose),99.05± 1.35,98.57± 1.96 (Max Dose) respectively.Two-related samples non-parametric tests suggested that the differences between the evaluation criteria were of statistical significance (Z =-7.220,-4.108,P＜0.05).For PD method,the γ 2D passing rates were 84.11％ ± 1.35％ (1 mm/1％),99.07％± 1.35％ (2 mm/2％),and 99.86％ ± 1.35％ (3 mm/3％).Two-related samples non-parametric tests suggested that the differences between evaluation criteria of PD method were statistically significant (Z =-7.475,-7.475,-6.906,P＜0.05).For 74 fields and max dose,3 mm/3％ evaluation criteria,two-related samples non-parametric tests suggested that the differences between PD and Oct1500 method were statistically significant (Z=-5.072,P＜0.05).Conclusions Both methods can be used for Halcyon pretreatment plan QA.PD is superior to Oct1500 with respect to efficiency and spatial resolution-induced verification accuracy.The criteria of 2 mm/2％ for PD,and Max Dose/3 mm/3％ for Oct1500 was suggested.