Objective:To compare and study the improvement of different iterative reconstruction(IR)algorithms of the tomotherapy(TOMO)Radixact system on the image quality of megavoltage computed tomography(MVCT)imaging system,and the influence of that on the precision of automatic registration,and to explore the reconstruction algorithm that is suitable for clinical application.Methods:Using the MVCT imaging system to respectively scan the Tomo-Phantom HE phantom and the Catphan 604 phantom,and to analyze three groups of images were generated by three kinds of reconstruction algorithms,which included the Standard(STD)algorithm,IR General(IR-G)algorithm and IR Soft Tissue(IR-ST)algorithm,in MVCT image.The noise index(NI),uniformity index(UI)of image,modulation transfer function(MTF),low contrast visibility(LCV)index and contrast-to-noise ratio(CNR)of three groups of images were calculated respectively.The Lucy phantom was used to test the accuracy of automatic registration algorithm.The registration data of four dimensions,included left-right(X-axis),head-foot(Y-axis),vertical(Z-axis)and free rotation(Roll)around the Y-axis,were used to conduct verification analysis for the influences of them on the precision of automatic registration.Results:The NI values of IR-G and IR-ST reconstruction algorithms were respectively 39.58±0.10 and 14.62±0.26,which were better than 39.58±0.10 of STD algorithm,and the UI values of them were respectively 19.87±0.83 and 15.84±2.51,which were better than 24.51±1.81 of STD algorithm,and LCV values of them were respectively 2.50±0.03 and 1.74±0.11,which were better than 3.67±0.04 of STD algorithm.All of them appeared significant increase,but the resolution with high contrast of MTF were respectively 0.23 and 0.21,which were lower than 0.32 of STD.The overall image quality of the IR algorithms was superior to that of the STD algorithm.In the accuracy test of the automatic registration algorithm,the registration precisions of IR-G and IR-ST algorithms on Y-axis were respectively(0.360±0.142)mm and(0.245±0.050)mm,which were significantly higher than 0.145±0.136 of STD algorithm,and the differences of them were significant(Z=6.0,15.0,P<0.05).The differences of registration precisions of other directions were not significant(P>0.05).Conclusion:The IR algorithm has advantages in terms of noise,uniformity and resolution with low-contrast,however,it shows reduction on resolution with high-contrast.This reduction of resolution with high-contrast do not lead to the decrease of the precision of automatic registration.

Objective:To evaluate the dosimetric characteristics, safety and effectiveness of magnetic resonance-guided fractionated stereotactic radiotherapy (FSRT) for brain tumors.Methods:Clinical data of 8 brain tumor patients treated with magnetic resonance-guided FSRT in the Radiotherapy Department of the First Medical Center of the PLA General Hospital from July 2023 to February 2024 were retrospectively analyzed. Online adaptive radiotherapy was adopted for all patients. Adapt-to-position (ATP) or adapt-to-shape (ATS) radiotherapy was chosen by radiologists. Each adaptation was initiated after the radiotherapy plan was re-examined. The radiotherapy fractionation plan was 21-30 Gy/3-5 F. Clinical characteristics, radiotherapy plans and plan parameters were analyzed by statistical description. Median ( Q1， Q3) was used to describe continuous data and percentage was used to describe categorical data. Results:In this study, 9 lesions were treated a total of 41 times, including 20 times (49%) of ATP plan and 21 times (51%) of ATS plan. The median target area coverage rate was 95.1% (95%, 99.8%), the median target area maximum dose rate was 1.15 (1.07, 1.31), the median conformity index (CI) was 0.75 (0.69, 0.86), the median homogeneity index (HI) was 1.09 (1.06, 1.21), and the median gradient index (GI) was 4.73 (3.36, 8.45), respectively. After ATS plan, the median reduction in gross target volume (GTV) was 8.22 cm3 (1.2, 10.1 cm3), and the median reduction in brain tissue V12 Gy was 30.46 cm3 (8.34, 31.13 cm3).The median follow-up was 3.2 months (1.4, 6.1 months). No radiation necrosis was found in any patient. There were 2 cases of acute brain edema during radiotherapy (both were mild). Except for 1 case who died due to systemic disease progression, the remaining patients had no local recurrence, and achieved good quality of life. Conclusions:The parameters of the treatment plan of magnetic resonance-guided FSRT are generally acceptable. The adaptive plan can effectively reduce the dose of normal brain tissues. It is safe and feasible to use the magnetic resonance-guided FSRT for brain tumors.

Objective:To evaluate the efficacy and safety of oral anisodine hydrobromide tablets in the treatment of nonarteritic anterior ischemic optic neuropathy (NAION).Methods:A multicenter nonrandomized controlled trial was conducted.A total of 282 acute NAION patients (282 eyes) were recruited from 16 hospitals in China from July 2020 to May 2021.Patients were divided into two groups according to treatment methods, which were control group (124 cases, 124 eyes) receiving regular treatment including citicoline sodium plus Ginkgo biloba leaf liquid extract or Ginkgo biloba leaf extract tablets plus mecobalamin, and experimental group (158 cases, 158 eyes) receiving treatment in control group plus oral anisodine hydrobromide tablets 1 mg, twice daily for 2 to 3 months.Best corrected visual acuity (BCVA), visual field index (VFI), peripapillary retinal nerve fiber layer (pRNFL) and radial peripapillary capillary vessel density (RPC) were assessed at 1, 2, 3, and 6 months after enrollment using the standard decimal visual acuity chart, 750i Humphery visual field analyzer, Cirrus HD-OCT 4000/Cirrus HD-OCT 5000, RTVue-XR optical coherence tomography respectively.The primary outcomes were BCVA and VFI, and the secondary outcomes were pRNFL, RPC, and the side effects during the follow-up.The study adhered to the Declaration of Helsinki.All patients were fully informed about the treatment and purpose of this study and voluntarily signed the informed consent form.The study protocol was approved by Chinese PLA General Hospital (No.S2020-021-01). Results:In all, 242 patients (242 eyes) completed the follow-up of BCVA, and 98 patients (98 eyes) completed the VFI follow-up.In terms of visual function, BCVA and VFI improved significantly over time in the two groups, and BCVA and VFI were better in experimental group than in control group at various follow-up time points (all at P<0.05). In terms of structure, pRNFL gradually decreased in both groups with the extension of treatment, and pRNFL was significanthy thinner in experimental group than in control group at various follow-up time points (all at P<0.05). There was no significant difference in RPC between the two groups at the last follow-up ( P>0.05). There were two cases with side effects and one case was discontinued due to side effects 25 days after enrollment. Conclusions:Oral anisodine hydrobromide can improve visual acuity and visual field in NAION and accelerate the regression of optic disc edema, with good safety.

Psoriatic arthritis (PsA) is a complicated psoriasis comorbidity with manifestations of psoriatic skin and arthritic joints, and tailoring specific treatment strategies for simultaneously delivering different drugs to different action sites in PsA remains challenging. We developed a need-based layered dissolving microneedle (MN) system loading immunosuppressant tacrolimus (TAC) and anti-inflammatory diclofenac (DIC) in different layers of MNs,

Objective To develop the information management system in the Department of Radiotherapy,optimize the procedures of radiotherapy, realize the informatization of radiotherapy process management and improve medical efficiency. Methods Multi-digital template was adopted to integrate the information of cancer treatment. The server was equipped with multi-terminal mode to establish the information management system of radiotherapy process. The work authority was assigned according to different positions. The system was connected with radiotherapy plan system (TPS),hospital information system (HIS) and picture archiving and communication system (PACS) to realize the information collection, recording charges, information transmission and plan evaluation and audit in Department of Radiotherapy. Results The information management system optimized the radiotherapy procedures,strengthened connection among different systems, linked the information systems among different departments, standardized the radiotherapy procedures and enhanced the clinical efficiency. Conclusions The application of information management system improves the management level of radiotherapy process, establish a unified standard for cancer treatment and provide complete management plans for the radiotherapy process and quality control. It is a unique and prospective system,which is advantageous in the management of treatment process,systematization of information collection and quality control.

Objective To elucidate the correlation between the enhancement degree of renal clearcell carcinoma (RCC) on dynamic contrast-enhanced CT and multiple vascular morphometric characteristics including microvessels and mature vessels.Methods A retrospective review was carried out on the records of 37 patients pathologically diagnosed with RCC who underwent plain and triphasic contrast-enhanced CT.The absolute (enhancement attenuation-pre-enhancement attenuation) and relative(absolute enhancement value÷cortex enhancement attenuation) enhancement values of RCC were measured in arterial,venous and delayed phases.And all lesions were divided into hypervascular and hypovascular groups.The number,mean area,perimeter and diameter,shape factor (4π*area/perimeter2) and the total area of microvessels and mature vessels were obtained by CD34 or a-SMA immunohistochemical staining.Then the correlation of radiographic parameters and various vascular morphometric parameters were analyzed.Results In arterial,venous and delayed phases,the absolute enhancement values were positively correlated with the number and the total area of microvessels and mature vessels (P<0.05),meanwhile the relative enhancement values were positively correlated with the number of microvessels and mature vessels(P<0.05).In venous and delayed phases,there were negative correlations of the relative enhancement values with mean area,perimeter and diameter of mature vessels(P<0.05).However, no correlations were found between other enhancement and vascular parameters (P>0.05).In addition, the significant differences in the number of microvessels and mature vessels between hypervascular and hypovascular groups were found (P<0.05).Conclusion CT enhancement degrees of RCC are related to multiple vascular morphometric indicators,which gives us more insights in the mechanism of RCC enhancement on CT.

President Xi presented an important address in the National Health and Wellness Conference and the high strategic priority for promoting people's health in China was emphasized. Thereafter, a number of documents of state policy on health and wellness were issued successively. These documents covered important contents on oral health, which had great significance as a milestone. This article reviewed the documentation process and analyzed the key points on oral health. The release of these series of government documents had provided policy support for integrating oral health into significant health policies, building the first barrier for oral health, preventing and treating oral diseases based on strategies for common risk factors, adopting strategies to combine both the whole population and high-risk groups, and developing health-centered oral massive health industry, etc.

Objective:To evaluate the efficacy of Piezosurgery in split teeth extractions.Methods:A single-center,randomized,split-mouth study was performed using a consecutive serious of unrelated healthy patients attending the departing of oral and maxillofacial surgery,Peking University School and Hospital of Stomatology.40 patients were selected for extraction of maxillary molars without reservation value,splitting or nonvital teeth.They were divided into control (20 patients)and test groups (20 pa-tients)randomly.Surgical treatments for both groups were under local anesthesia.Molar teeth of control group were extracted by common equipments like dental elevators,chisels,forceps,etc.While molar teeth of experimental group were extracted by Piezosurgery,aided with the use of common equipments if needed.Then we compared the duration of surgery,frequency of the usage of chisels,expansion of post-operative bony socket surgical discomfort and postoperative pain between two groups.Results:The ave-rage of operation time was (629.5 ±171.0)s in control group and (456.0 ±337.2)s in test group.The buccal alveolar bone reduced (1.07 ±0.64)mm in control group and (1.49 ±0.61)mm in test group. There was a significant difference between the two groups (P <0.05).The duration of surgery for experi-mental group was significantly longer than that of the control group,but the change of buccal alveolar bone was lower than the control group.For visual analogue scale (VAS)value of surgical discomfort,ex-pansion of postoperative bony socket and the operative fear rate,there were no significant difference be-tween the two groups (P >0.05).Conclusion:Piezosugery can be better to preserve alveolar bone,re-duce trauma and patient’s fear.Application of the piezosugery reflect the characteristics of minimally in-vasive extraction,which has the value of promotion.The Piezosurgery technique have the advantage of re-ducing change of buccal alveolar bone during the surgery,but a longer surgical time was required when compared with the conventional technique.VAS value of surgical discomfort,expansion of postoperative bony socket and the operative fear rate,there were no significant difference.Minimally invasive tooth ex-traction technique has good clinical results and high satisfaction.Piezosurgery proved its worth as the in-strument adapted to limiting the destruction of bone tissue.

Objective:To investigate the defect types and reconstruction methods of maxillary defects. Methods:The database of 1 107 cases with maxillary defects in Peking University School and Hospital of Stomatology from January 1985 to December 2010 was established. There construction methods were re-viewed. The defect types were classified according to Brown classification system. Results: In the 1 107 cases, 1 104 cases could be classified according to Brown classification system. The most common type was 2a with 559 cases (50. 6%). Among all the 1 107 cases, 349 cases were reconstructed with auto-transplantation, 443 cases with prosthesis, 107 cases untreated, and 208 patients lost to the follow-up. There was a significant growing trend over time for the application of free flaps and a downward trend of prosthesis. The most popular free flaps were fibular flap (88 cases) and radial forearm flap (75 cases) . Rectus abdominis flap and anterolatreal thigh flap were fit for extensive maxillary defects. Conclusion:The most common defect type is 2a. Free flap has become the dominant option for maxillary reconstruc-tion. Free flaps could be selected according to the maxillary defect types.

Hot-melt extrusion was applied to prepare mesoporous silica/ethylcellulose mini-matrix for sustained release, and fenofibrate was used as a model drug, ethylcellulose and xanthan gum were chosen as sustained-release agent and releasing moderator, respectively. This novel matrix obtained the controlled release ability by combining mesoporous silica drug delivery system and hot-melt extrusion technology. And mesoporous silica particle (SBA-15) was chosen as drug carrier to increase the dissolution rate of fenofibrate in this martix. Scanning electron microscope, transmission electron microscope, small angle X-ray powder diffraction and N2 adsorption-desorption were introduced to determine the particle morphology, particle size and pore structure of the synthesized SBA-15. The results showed that SBA-15 had a very high Brunauer-Emmett-Teller specific surface area, a narrow pore size distribution, large pore volume and a ordered two-dimensional hexagonal structure of p6mm symmetry. Differential scanning calorimetry and X-ray powder diffraction results demonstrated that fenofibrate dispersed in an amorphous state inside the pores of the mesoporous silica which contributed to the improvement in the dissolution rate. The drug release of mini-matrices was influenced by ethylcellulose viscosity grades and xanthan gum concentration, which increased with the increasing of xanthan gum concentration and decreasing of ethylcellulose viscosity. Mini-matrix containing 22% xanthan gum exhibited a good sustained release performance, and the drug release behavior followed the first-order kinetics.