Effects of Ranibizumab on ocular biological parameters in the treatment of retinopathy of prematurity / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of intravitreal ranibizumab injection on ocular parameters in the treatment of retinopathy of prematurity(ROP), and analyze its relationship with birth weight(BW)and postmenstrual age(PMA).METHODS: A total of 98 premature infants who received routine ROP screening at Northwest Women's and Children's Hospital from January 1, 2016 to January 31, 2022 were selected, and they were divided into ROP group(49 cases)and non-ROP group(49 cases)according to the results of Retcam3 fundus screening. All children in ROP group were treated with intravitreal ranibizumab injection, with an average PMA of 38.02±3.03 weeks. The ocular parameters were measured at the PMA of 0 month(40 weeks±14d), 3 months(52 weeks±28d)and 6 months(64 weeks±28d), respectively.RESULTS: There was no difference in axial length(AL), anterior chamber depth(ACD), lens thickness(LT), vitreous length(VL)and central corneal thickness(CCT)between ROP group and non-ROP group at the PMA of 0 month(P>0.05); At the PMA of 3 and 6 months, ACD in ROP group was higher than that in non-ROP group, and LT was lower than that in non-ROP group(P<0.05); at the PMA of 6 months, AL and VL in ROP group were lower than those in non-ROP group(P<0.05). AL, ACD and VL were positively correlated with PMA in ROP group and non-ROP group, while CCT was negatively correlated with PMA; there was a positive correlation between LT and PMA in children without ROP. There was no correlation among LT, BW and PMA in ROP group.CONCLUSION: The ocular development of children with early ROP(PMA 0～6 months)treated by intravitreal ranibizumab injection is slower than that of premature infants without ROP, and BW and PMA are the main influencing factors of ocular parameters of premature infants.

Biometric investigation of ocular components in various types of anisometropia in school-age children / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To compare the differences and correlations between different types of anisometropia, binocular visual acuity and biological parameters in school-age children.METHODS: A total of 128 school-age children(6-12 years)with mild-to-moderate anisometropia were retrospectively analyzed. Subjects were divided into five groups according to anisometropia type. All participants underwent cycloplegic refraction, A-scan ultrasound biometry, and corneal topography. Refractive status, best-corrected visual acuity(BCVA), anterior chamber depth(ACD), lens thickness(LT), vitreous chamber depth(VCD), axial length(AL), corneal radius(CR), and ratio of AL and CR(AL/CR)were recorded. Kruskal-Wallis and Spearman rank correlation tests were then used for statistical analysis.RESULTS: Hyperopic anisometropia had the greatest binocular vision difference(0.14±0.20). Myopic anisometropia had the greatest asymmetry in AL and VCD(0.56±0.41 and 0.56±0.39 mm, respectively). Anisometropia was positively correlated with BCVA, VCD, AL, and AL/CR(r=0.266, 0.379, 0.350, 0.263, respectively; P<0.05), and it was not significantly correlated with LT and CR(r=-0.019,-0.069, respectively; P>0.05), while no parameters had a statistically significant correlation with anisometropia in each group.CONCLUSION: School-age children with hyperopic anisometropia showed the greatest difference of binocular acuity in the four types of anisometropia. The inter-ocular differences of biometric parameters in simple hyperopic or myopic anisometropia were mainly attributed to the asymmetry of VCD and AL, while the differences in ocular parameters were not statistically significant in school-age children with astigmatic anisometropia.

Application of machine learning in the therapeutic drug monitoring and individual drug therapy / 中国药房

Machine learning has been applied in the medical field due to its powerful data analysis and exploration capabilities. In recent years， more and more studies have applied it to therapeutic drug monitoring and individual drug therapy of immunosuppressants， anti-infective drugs， antiepileptic drugs， etc. Compared with the traditional population pharmacokinetic modeling methods， the constructed models based on machine learning can predict blood drug concentration and drug dose more accurately， improve the level of clinical precision drug use and reduce the occurrence of adverse drug reactions. Based on this， this article reviews the application of machine learning in therapeutic drug monitoring and individual drug therapy， with a view to providing theoretical basis and technical support for clinical precise drug use.

Common protocol deviations and improvement methods and precautions in drug clinical trials / 中国药房

OBJECTIVE To learn the common proto col deviation （PD）in the process of drug clinical trials and discuss the methods and precautions for preventing and reducing PD so as to provide reference for the standardization of drug clinical trials. METHODS According to Good Clinical Practice ，Notice on Issuing Guidelines for Planning and Reporting of Data Management and Statistical Analysis of Drug Clinical Trials ，Guidelines for Ethical Review of Drug Clinical Trials ，ICH E 3，ICH E 6（R2）and other regulations ，the PD reported in the relevant projects managed by the author from March 2017 to February 2022，as well as the PD found in the submission materials and project quality control ，were sorted out and statistically analyzed. RESULTS & CONCLUSIONS A total of 39 drug clinical trials were included ，and 212 subjects were selected. In all projects ，258 PDs were reported，including 28 major PD （accounting for 10.85％）and 230 ordinary PD （accounting for 89.15％）. The report of PD mainly included missed inspections/tests （93 reports，accounting for 36.05％），lack of visits （36 reports，accounting for 13.95％）， inspection/testing out-of-window （29 reports，accounting for 11.24％），dosage and usage of test drugs （28 reports，accounting for 10.85％），drug over-temperature/missing temperature （21 reports，accounting for 8.14％），etc. Avoiding and reducing the occurrence of PD requires the efforts of multiple parties ：the sponsor designs a reasonable protocol with appropriate interview rate and window period after listening to the opinions of multiple parties ；the investigators and clinical research coordinator should strengthen their own learning and training ，and be familiar with the protocol ，Good Clinical Practice and corresponding regulations；the compliance education of the subjects should be strengthened ；the institutional offices and ethics committees should conduct multi-angle and whole-process supervision and management when a drug clinical trial is approved ，in progress ，and jsyj- concluded，to ensure the safety rights and interests of the zdcxX0079） subjects and the quality of clinical trials. On this basis ，all parties should communicate effectively and timely ，report PD in time ，and conduct special studies on major PD that have com occurred and key links that are prone to PD.

Application of project-based learning in clinical teaching of radiation physics for radiotherapy residents / 中华放射肿瘤学杂志

Objective:To observe the effect of project-based learning (PBL) in the clinical teaching of radiation physics.Methods:Thirty-two residents specializing in radiotherapy were included in the study. In the experimental group ( n=16), PBL was adopted, while traditional clinical teaching method was employed in the control group ( n=16). After the rotation, the assessment was conducted, as well as a questionnaire survey was performed, including five aspects: overall satisfaction, understanding of radiation physics knowledge, learning motivation, learning burden, and learning efficiency. Results:The assessment score in the experimental group was 86.31±5.41, which was higher than 75.28±5.91 in the control group, and the difference was statistically significant. Residents in the experimental group were satisfied with the effect of PBL.Conclusion:Compared with the traditional teaching method, PBL can improve the learning motivation, efficiency, and performance of radiotherapy residents, which is highly recognized by the residents.

Analysis of the National Natural Science Foundation of China grant support for the field of cataract study during the past ten years / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyze the funding status of cataract research funded by National Natural Science Foundation of China from 2010 to 2019, and discuss the development focus on basic cataract research in the near future, so as to provide reference information for researchers in the field of cataract to understand the progress of basic research and apply for funding.<p>METHODS: The cataract research projects funded by the National Natural Science Foundation of China from 2010 to 2019 were counted. The categories of funded projects, project title, fund amount, applicant unit and region, approved year and key words were statistically analyzed. <p>RESULTS: In the past ten years, the number of cataract research projects and the amount of funding accounted for 9.35% and 9.72% of the total amount of the whole ophthalmology area respectively. The number of projects in ophthalmology and cataract research and the amount of aid received generally showed a wavy upward trend. The key words in the project setup are gradually increasing, and more and more inclined to mechanism research. With the development of computer aided technology, TALEN technology and total exon sequencing technology, cataract research presents a trend of integration of medicine and other disciplines. East China, especially Shanghai, ranks first in terms of the number of projects and funds received. Among the categories of projects, the number and funding are the largest among the general projects. In recent years, the number of the Youth Science Foundation projects has risen strongly, and even exceeds the general projects in some areas. <p>CONCLUSION: The focus of cataract research from 2010 to 2019 tends to be diversified. The integration of multi-disciplines and the application of new techniques and methods are prominent features. The fund amount and the level of research are unbalanced in regional development.

An automatic VMAT planning method for primary liver cancer radiotherapy based on predicting the feasibility DVH / 中华放射肿瘤学杂志

Objective:To establish an automatic planning method using volumetric-modulated arc therapy (VMAT) for primary liver cancer (PLC) radiotherapy based on predicting the feasibility dose-volume histogram (DVH) and evaluate its performance.Methods:Ten patients with PLC were randomly chosen in this retrospective study. Pinnacle Auto-Planning was used to design the VMAT automatic plan, and the feasibility DVH curve was obtained through the PlanIQ dose prediction, and the initial optimization objectives of the automatic plan were set according to the displayed feasible objectives interval. The plans were accessed according to dosimetric parameters of the planning target volume and organs at risk as well as the monitor units. All patients′ automatic plans were compared with clinically accepted manual plans by using the paired t-test. Results:There was no significant difference of the planning target volume D 2%, D 98%, D mean or homogeneity index between the automatic and manual plans ((58.55±2.81) Gy vs.(57.98±4.17) Gy, (47.15±1.58) Gy vs.(47.82±1.38) Gy, (53.14±0.95) Gy vs.(53.44±1.67) Gy and 1.15±0.05 vs. 1.14±0.07, all P>0.05). The planning target volume conformity index of the manual plan was slightly higher than that of the automatic plan (0.77±0.08 vs. 0.69±0.06, P<0.05). The mean doses of normal liver, V 30Gy, V 20Gy, V 10Gy, V 5Gy and V< 5Gy of the automatic plan were significantly better than those of the manual plan ((26.68±11.13)% vs.(28.00±10.95)%, (29.96±11.50)% vs.(31.89±11.51)%, (34.88±11.51)% vs.(38.66±11.67)%, (45.38±12.40)% vs.(50.74±13.56)%, and (628.52±191.80) cm 3vs.(563.15±188.39) cm 3, all P<0.05). The mean doses of the small intestine, the duodenum, and the heart, as well as lung V 10 of the automatic plan were significantly less than those of the manual plan ((1.83±2.17) Gy vs.(2.37±2.81) Gy, (9.15±9.36) Gy vs.(11.18±10.49) Gy, and (5.44±3.10) Gy vs.(6.25±3.26) Gy, as well as (12.70±7.08)% vs.(14.47±8.11)%, all P<0.05). Monitor units did not significantly differ between two plans ((710.67±163.72) MU vs.(707.53±155.89) MU, P>0.05). Conclusions:The automatic planning method using VMAT for PLC radiotherapy based on predicting the feasibility DVH enhances the quality for PLC plans, especially in terms of normal liver sparing. Besides, it also has advantages for the protection of the intestine, whole lung and heart.

Design of a drum-shaped applicator through Monte Carlo simulation for breast intraoperative radiotherapy / 中华放射肿瘤学杂志

Objective:To design a drum-shaped applicator through Monte Carlo simulation for breast intraoperative radiotherapy.Methods:Applicator designing process is as follows: first, determined the shape of the applicator based on the geometric characteristics of the breast tumor bed closed to the chest wall; second, calculated the scattering angle and dose rate of the electron beam after passing through a series of scattering foils of different thicknesses to determine the thickness of the scattering foil; thrid, modeled the layer according to the applicator′s geometric characteristics where modulator located, and designed the modulator through the relationship between the geometric characteristics of the layer and the surface dose of the applicator. EGSnrc/BEAMnrc and EGS4/DOSXYZ were employed to model the head of the Mobetron, the layer, the applicator, and to calculate the dose distributions.Results:The applicator has two components. The upper component is a 3cm-diametre cylindrical collimator with 0.5cm wall made of 0.3cm steel and 0.2cm water equivalent material (WEM), a 0.13cm-foil made of tansgen. The lower component is a 4cm-diametre drum made of 0.2cm WEM and a 0.14cm maximum thickness hill-shaped modulator made of steel. When the energy of electron beam was 12MeV, the dose rate was about 90.44 cGy/min, and the depth of the 50% isodose curve was 1cm.Conclusion:The applicator is successfully designed, and can obtain a drum-shaped dose distribution.

Design of a semi-spherical applicator for intraoperative radiotherapy with a linear accelerator and assessment of its dosemetric characteristics based on Monte Carlo simulation / 中华放射医学与防护杂志

Objective:To design a semi-spherical applicator for delivery of semi-spherical dose distributions and assess its dosemetric characteristics.Methods:The applicator was designed in the following way. First, the scattering angle and dose rate of the electron beam having passed through a series of scattering foils of different thicknesses were calculated to determine the thickness of the scattering foil. And then, a series of location model was designed, and the variances of the mean electron energy on the surface of these models were calculated to determine the foil location. Finally, the relationship between the geometric characteristics of the layer and the surface dose on the applicator was established to design the modulator. Monte Carlo (MC) codes EGSnrc/BEAMnrc and EGS4/DOSXYZ were employed to model the head of the Mobetron, the location model, the layer, the semi-spherical applicator, and to calculate the dose distributions.Results:A semi-spherical applicator was designed for electron beam of energy 12 MeV, which consisted of a 2.5 cm diametre cylindrical collimator with 0.5 cm thick wall made of 0.3 cm thick steel and 0.2 cm thick water equivalent material (WEM), a 0.14 cm-thick foil made of tansgen, and a 2.5 cm diametre hollow semi-sphere containing a crescent modulator made of WEM. The dose rate was about 160 cGy/min, and the depth of the 50% isodose curve was 0.85 cm.Conclutions:We designed and performed a MC simulation of a semi-spherical applicator to deliver a semi-spherical dose distribution from a high energy electron beam.

A method of determining the prescription isodose line for stereotactic radiotherapy VMAT plan / 中华放射医学与防护杂志

Objective:To establish a method of determining the prescription isodose line for steretactic radiotherapy (SRT) volumetric modulated arc radiotherapy (VMAT) plan.Methods:Eight patients with brain metastases treated with SRT were enrolled. The volume of planning target volume (PTV) ranged from 3.5 to 11.7 cm 3 (median 6.1 cm 3). Reference VMAT plans were designed for each patient with identical prescription dose. Then, the original PTV was contracted by a few millimeters to form a new target for optimization to get plans with different IDLs. The minimum margin which was needed to be contracted to achieve optimal IDL range for each PTV was also studied. Results:To achieve the optimal IDL range, 4 or 5 mm PTV contraction was needed for all patients, and the average IDL was (66.05±0.02)%. Compared with reference plans, the average gradient index (GI) of optimal IDL plans decreased by 20% from 4.05±0.39 to 3.37±0.24 ( Z=-2.521, P<0.05). The V40, V30, V5 and mean dose in normal brain tissue decreased by 11.5% ( Z=-1.973, P<0.05), 7.2% ( Z=-2.105, P<0.05), 12.8% ( Z=-2.521, P<0.05) and 8.1%, respectively ( Z=-2.382, P<0.05), and there was no statistically significant difference with V20, V10 and conformity index ( P>0.05). Conclusions:The optimization of IDL for SRT-VMAT plan can be achieved with the method of contracting PTV to form new target for planning. 4 or 5 mm is needed to be contracted to achieve the optimal IDL range, and to get lower GI and protect the normal brain tissue.

The microdamage of " morphologically normal white matter" in patients with nasopharyngeal carcinoma after radiotherapy and its correlation with the irradiation dose / 中华放射肿瘤学杂志

Objective@#To explore the correlation between microdamage in white matter and radiotherapy dose at early stage after radiotherapy (RT) in patients with nasopharyngeal carcinoma (NPC).@*Methods@#Thirty-three patients who were initially diagnosed with NPC were recruited and received diffusion tensor imaging (DTI) scan and neuro-cognitive scale test within 1 week before RT and the first day after RT. DTI-related characteristic parameters including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ‖), and radial diffusivity (λ⊥) were calculated based on whole-brain voxel analysis method. Paired t-test was conducted to evaluate statistical significance between pre-RT and post-RT groups. In the subgroup analysis, all the subjects were divided into 3 groups according to the average dose of temporal lobe, and each group was set with an equal dose interval range. The DTI-related parameters of whole brain pre-RT and post-RT in each group were statistically compared. All the statistical results were corrected by FDR with a threshold of P<0.05 and clusters>100.@*Results@#FA, MD, λ‖ and λ⊥in the post-RT group significantly differed compared with those in the pre-RT group (P<0.05). The values of FA, MD, λ‖ and λ⊥were 0.455±0.016, (9.893±0.403)×10-4, (13.441±0.412)×10-4 and (8.231±0.429)×10-4, respectively. Subgroup analysis showed that the extent and degree of λ‖ and λ⊥ changes were exacerbated with the increase of the average dose of temporal lobe after RT. Particularly in high-dose group, the average dose range was 25-35 Gy and the extent of regions with significant changes was significantly larger than those in the medium-dose (15-25 Gy) and low-dose groups (5-15 Gy)(P<0.05).@*Conclusions@#DTI can be utilized to detect" normal" brain tissue microdamage in NPC patients at early stage after RT. The average radiation dose of temporal lobe may be one of the reasons for the severity of cerebral microdamage. In the future, DTI technique may be useful for guiding exposure dose of organs at risk during RT planning and to evaluate the cohort with a high risk of cerebral microdamage at early stage after RT, thereby protecting normal cerebral tissues to the maximum extent.

Realization and application of automatic independent check software for radiotherapy treatment plans / 中华放射肿瘤学杂志

Objective@#To design and implement an automatic independent check software (AutoReview) for the radiotherapy treatment plan and improve the efficiency of independent check.@*Methods@#The patient′s electronic treatment plan chart in the record and verify (R&V) system database accessed by the SQL language was read and parsed. Based on the treatment plan information obtained from the chart, AutoReview extracted all parameters related to the treatment plan from the treatment planning system and the R&V system, and saved the structured data into a local database. For different check items, corresponding check logic was designed and the program was written to realize the automatic independent check. In total, 664 clinical treatment plans for one month were selected as a sample to evaluate the clinical application effect.@*Results@#Compared with manual check, AutoReview improved the check efficiency by nearly 60 times and the problem detection rate was elevated by 19.2%. In the two-year clinical application, the software operation was stable, and 14509 treatment plans were automatically checked and identified 588 cases with problems, accounting for 4.05%.@*Conclusion@#AutoReview can effectively improve the efficiency and accuracy of independent check in radiotherapy treatment plan.

Small field output factor measurement and correction method based on IAEA report No.483 / 中华放射肿瘤学杂志

Objective The IAEA report No.483 describes the latest method of small field dosimetry.The field output factor measurement and correction methods are used to improve the accuracy and consistency of the measurement results for different type detectors.Methods The field output factors from 0.6 cm×0.6 cm to 10 cm× 10 cm were measured using IBA's CC13 ionization chamber,CC01 ionization chamber,PFD semiconductor detector,EFD semiconductor detector and Razor semiconductor detector,respectively.The field output correction factors were used to correct the measurement result.Results Compared with the corrected data,the results of ionization chamber are mainly affected by the volume averaging and the fluence perturbation effect,lead to the measurement result which is 4.70％ lower at 0.6 cm × 0.6 cm;The results of Shielded semiconductors are mainly affected by fluence perturbation effect,lead to the measurement result which is 4.80％ higher at 0.6 cm × 0.6 cm.The results of unshielded semiconductors are mainly affected by energy response and fluence perturbation effect,resulting in lower measurement results at the field size＞0.8 cm×0.8 cm,2.10％ lower at field size of 1.5 cm× 1.5 cm,higher measurement results at field size＜0.8 cm×0.8 cm and 1.1％ higher at field size of 0.6 cm×0.6 cm.Before the correction,the measurement results from different types of detectors are quite different,average standard deviation is 0.016 6.After the correction,the difference among the detectors is significantly reduced,average standard deviation is 0.006 6.Conclusions For detectors such as ionization chambers and semiconductors,the field output correction factors can be used to correct the output factors of the small field to improve the accuracy and consistency of the measurement results.

Novel sesquiterpenoids isolated from Chimonanthus praecox and their antibacterial activities / 中国天然药物

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL. The present study provided a basis for future evaluation of these compounds as antibacterial agents.

Novel sesquiterpenoids isolated from Chimonanthus praecox and their antibacterial activities / 中国天然药物

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL. The present study provided a basis for future evaluation of these compounds as antibacterial agents.

Preparation process and in vitro evaluation of Shufei in situ gel optimized by central composite design-response surface methodology / 中草药

objective To optimize the preparation technology of sulfuric in situ gel and study the infiltration experiment of different dosage forms. Methods Shufei in situ gel was prepared by cold cut method with poloxamer 188 (P188) and poloxamer 407 (P407) as gel base. Using gelling temperature index, the dosage range of gel matrix P407 and P188 in Shufei in situ gel was determinated by the single factor and star design-response surface methods to get the best prescription of Shufei in situ gel. The transdermal diffusion process of Shufei in situ gel was carried out in Franz diffusion cells to explore the permeation mechanism. Results The optimized prescription of Shufei in situ gel was as follow: The ratio of gel matrix to drug at 1:3, P188 dosage of 4%, P407 dosage of 22.5%, and the phase transition temperature within 32-36 ℃ to form gel. The releases of sinapine thiocyanate and genkwanin in Shufei in situ gel were all in line with the Higuchi release model. Conclusion The preparation process of Shufei in situ gel is stable and feasible with reliable product quality and good application prospect, which is suitable for industrial production and clinical application.

Monte Carlo simulation of accurate dose distribution with high resolution for the single source channel of Leksell 4C gamma knife / 中华放射肿瘤学杂志

Objective@#To obtain the high-resolution dose distribution for the single source channel of Leksell 4C gamma knife.@*Methods@#A parallel computing platform based on the Message Passing Interface (MPI) and Monte Carlo Code MCNPX was established. The ring-shaped detector and two pre-validated variance reduction techniques (emission direction-biased sampling of source and termination of electron tracking in partial structures) were adopted to derive the high-resolution dose distribution for the single source channel of Leksell 4C gamma knife. The effect of cut-off energy for both photon and electron on the accuracy of simulation outcomes was evaluated and statistically compared.@*Results@#Compared with previous findings, the spatial resolution of the dose distribution for the single source channel obtained in this study was higher (radial resolution=0.1 mm) with less statistical error (<1%). The calculation time was acceptable (approximately 24 h). For the 4-, 8-, 14-and 18-mm variable collimators, the penumbra and full width at the half maximum (FWHM) for single side were 1.0, 1.1, 1.2, 1.3 mm and 2.2, 4.3, 7.3, 9.3 mm, respectively, which were consistent with previous studies. The difference of the simulation results was extremely small between different cut-off energy for photon (1 keV vs.10 keV). However, the simulation results significantly differ between 1 and 521 keV electronic cut-off energy.@*Conclusions@#The MCNPX parallel computing platform based on the MPI environment can be utilized to derive highly accurate dose distribution with high resolution in acceptable calculation time. The cut-off energy of the photon and electron should be cautiously set up during simulation.

A method of measuring the field output factor based on daisy-chaining / 中华放射肿瘤学杂志

Objective improve the accuracy of the measurement results by using the field output factor measurement method based on daisy-chaining.Methods The Varian Edge Accelerator 6 MV X-ray data were measured using the IBA CC13 ionization chamber, IBA CC01 ionization chamber, IBA Razor semiconductor detector , IBA EFD semiconductor detector and Gafchromic EBT 3 film , respectively. Results Compared with the daisy-chaining measurement method,the results obtained by the conventional measurement method using CC13 were smaller. The deviation value was 16. 71% in the 1 cm × 1 cm field. The measurement results in a larger field via CC01 were bigger with a deviation of 8. 39% in the 40 cm × 40 cm filed. The measurement results via Razor in a larger field were larger with a deviation of 9. 40% in the 40 cm × 40 cm field. The measurement results were similar between EFD and Razor with a deviation of 9. 14% in the 40 cm × 40 cm field. The results of the film measurement were equivalent to those obtained from the daisy-chaining method in a field of＞ 1 cm × 1 cm with a deviation within 1. 60%,whereas the deviation was increased to 3. 13% in the 1 cm× 1 cm field. The results were consistent with daisy-chaining measurement if the 3 cm × 3 cm or 4 cm × 4 cm fields were selected as the intermediate fields with the maximum deviation of 0. 29%. Conclusions For the detectors with changing response along with the field size,daisy-chaining measurement method can be utilized to extend the measurement range and improve the accuracy of the measurement results.

Study on preparation of Compound Xiongqi Maichong Tablets / 中草药

Objective: To prepare Compound Xiongqi Maichong Tablets (CXMT) by selecting ligustrazine and Panax notoginseng saponins (PNS) in the treatment of coronary heart disease as a model drug, using hypromellose (HPMC) as coating material, and control of drug release delay as 4 h. Methods: The core system of CXMT was prepared by direct powder compression method; The best coating prescription and preparation of CXMT by press coated was optimized by central composite design and response surface method. The release model was fitted by DDsolver software, and the synchronous release of drug was studied. Results: The in vitro cumulative release fitting order of CXMT preparation was Logistic > Higuchi; Logistic model fitting degree was 0.950 1, and AIC was 29.432 0. So the drug release mechanism of CXMT was type S dissolution process, and the in vitro cumulative release model was the Logistic model. Conclusion: Through the study of CXMT preparation technology and the drug release mechanism, the quality of the prepared CXMT is stable, and the lag time is 4 h; Different components of the cumulative dissolution rate are over 90%, which reach the pulse drug release standard.

Clinical effect of intraoperative electron beam radiotherapy in treatment of unresectable locally advanced pancreatic cancer / 中华放射肿瘤学杂志

Objective To assess the prognostic benefits of intraoperative radiotherapy (IORT) with electron beam among patients with unresectable locally advanced pancreatic cancer.Methods Between January 2009 and December 2014,167 patients with unresectable locally advanced pancreatic cancer received IORT with electron beam (10-20 Gy) in our hospital.After surgery,12 patients were treated with external beam radiotherapy,56 patients with chemoradiotherapy (CRT),and 17 patients with chemotherapy.Overall survival (OS),local recurrence,and toxicities were retrospectively analyzed.The Kaplan-Meier method was used to calculate survival rates,the log-rank test was used for survival difference analysis and univariate prognostic analysis,and the Cox model was used for multivariate prognostic analysis.Results The follow-up rate was 100％.The median OS time was 10.3 months,and the 2-year OS rate was 22％.The median progression-fiee survival (PFS) time was 6.3 months,and the 2-year PFS rate was 9.9％.The cancer-specific survival (CSS) time was 11.2 months,and the 2-year CSS rate was 23.6％.In the patients treated with IORT alone at doses of＜15 Gy,15 Gy and＞15 Gy,the median OS times were 6.2 months vs.9.1 months vs.22.2 months,and the 1-year OS rates were 10.0％ vs.39.6％ vs.74.4％ (P=0.000).Among the patients receiving postoperative adjuvant therapy,those treated with IORT+CRT had the best survival,with a median OS time of 11.6 months (P=0.033).The univariate analysis showed that IORT dose (P =0.000),tumor size (P =0.006),and IORT applicator diameter (P =0.007) were prognostic factors.The multivariate analysis showed that IORT dose (P=0.000) and IORT combined with CRT (P=0.006) were independent prognostic factors.Conclusions IORT with electron beam is an effective and safe treatment strategy for unresectable locally advanced pancreatic cancer.After protecting surrounding organs,increasing the IORT dose can improve the survival.IORT combined with CRT should be recommended because it improves survival for unresectable locally advanced pancreatic cancer without increasing toxicities.