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Objective @#To verify the feasibility of using a homemade lung phantom for quality control of Cyberknife by comparing the measurement results of the homemade lung phantom and CIRS dynamic phantom in E2E testing of Cyberknife lung tracking. @*Methods @#The patient treatment process was simulated, including CT positioning, plan design, irra- diation implementation, film scanning, and analysis using the homemade phantom and CIRS phantom. The two phantoms were measured five times using MLC under the S7 generation Cyberknife and five times using Iris under the M6 generation Cyberknife. The differences in measurement results between the two phantoms were analyzed using independent sample t-test.@*Results @#For the S7 generation Cyberknife, the statistical analysis of differences between the two phantoms in the detection values on the X-axis, Y-axis, Z-axis, and total deviation showed P values of 0.236, 0.175, 0.289, and 0.668, respect- ively. For the M6 generation Cyberknife, the statistical analysis showed P values of 0.880, 0.891, 0.573, and 0.433, respect- ively. The P values were all > 0.05. Therefore, there were no statistically significant differences in the detection results between the homemade lung phantom and the CIRS phantom under the S7 and M6 generation Cyberknife. The total deviation values were <1.5 mm.@*Conclusion @#The homemade lung phantom and CIRS phantom have consistent measurement results in the E2E testing of Cyberknife lung tracking and meet the requirements of Report of AAPM TG-135 and WS 667- 2019 standard. Therefore, the homemade lung phantom is feasible for clinical quality control of Cyberknife.
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Objective:To evaluate the radiation shielding performance for a novel self-shielded ZAP-X radiotherapy system used for intra-cranial and neck treatments. The present evaluation was performed according to the relevant Chinese national standards and the clinical placement of the radiotherapy system in an unshielded treatment room.Methods:The radiation source of the ZAP-X was a 3 MV linear accelerator. A total of 33 detection sites were selected surrounding the self-shielded system at 1.3, 2.3 and 3.3 m away from the periphery of the equipment. The maximum ambient dose equivalent rate in each irradiation condition was measured accordingly. A commonly used clinical treatment plan was selected to simulate the treatment process. During the delivery of this treatment plan, the cumulative doses of these 33 sites were measured, separately. The applicable current radiation protection standard for radiotherapy in China was chosen to evaluate the radiation shielding performance of the system.Results:According to the measurement result of the ambient dose equivalent rates along the aforementioned perimeter lines, a suggestion was put forward to redefine the existing 1 m controlled area by determining the distance at which the instantaneous dose rate of 10 μSv/h will not be exceeded. This is to meet the requirements of the Chinese standard GBZ 121-2020.Conclusions:According to the existing Chinese national radiation protection standards, the self-shielded radiotherapy system in the unshielded treatment room has the clinical applicability in China. But for such a novel self-shielded system, the corresponding performance testing and radiation protection standards shall be formulated.
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Objective To explore the feasibility of quartz glass for radiotherapy dosimetry through the experimental study of the thermoluminescence characteristics of synthetic quartz glass. Methods The thermoluminescence glow curves of quartz glass under different annealing conditions were analyzed, the thermoluminescence characteristics of quartz glass were studied, and the measurement parameters were optimized. Using the Co-60 reference radiation field in the National Secondary Standard Dosimetry Laboratory, the quartz glass samples under different annealing conditions were irradiated following the dose levels of radiotherapy, i.e., 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 Gy, respectively. According to the relationship between the absorbed dose of quartz glass and the relative thermoluminescence signal intensity, the linearity and dispersion of the dose response of quartz glass were obtained, and the feasibility of quartz glass for radiotherapy dosimetry was analyzed. Results The linear correlation coefficient of dose response of quartz glass under annealing condition of 430℃ for 10 min was 0.9984, and the dose response dispersion was 0.97% at the absorbed dose of 2 Gy. The linear correlation coefficient of dose response of quartz glass under annealing condition of 600℃ for 1 h was 0.9911, and the dose response dispersion was 1.4% at the absorbed dose of 2 Gy. Conclusion Preliminary results suggest that quartz glass with annealing condition of 430℃ for 10 min has the potential to be used for radiotherapy dosimetry.
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Objective:To provide reference for establishing the testing method for quality control of neutron beam in boron neutron capture therapy (BNCT) equipment in China by testing the radiation characteristic parameters and dosimetry characteristic parameters of epithermal neutron beam in hospital neutron irradiator (IHNI).Methods:By comparing the uncertainties in the result of various test items with the deviation values recommended by the European Joint Research Center (EC-JRC), the feasibility of the relevant of testing method was analyzed and evaluated.Results:The uncertainty in epithermal neutron fluence rate was 2.7%. The uncertainty in ratio of thermal to epithermal neutron fluence rate was 3.1%. The uncertainty in ratio of fast neutron air kerma to epithermal neutron fluence rate was 9.3%. The uncertainty in ratio of gamma air kerma to epithermal neutron fluence rate was 8.7%. The uncertainty in spatial distribution of neutron fluence rate was 2.7%. The uncertainty in thermal neutron fluence rate in phantom was 1.8%. The uncertainty in neutron and gamma-ray dose rate in phantom was 17.1% and 4.0%, respectively.Conclusions:The uncertainty in neutron dose rate measurement result in phantom is higher, and further research is needed to improve the accuracy of the testing method. The uncertainty in the measurement result of other test items is lower, and the accuracy of the test result is expected to meet the allowable deviation value recommended by the European Joint Research Center, and the test method is feasible.
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@#<b>Objective</b> To calculate the energy dependence of absorbed dose in EBT3 film, and to reveal the error in the measurement of proton absorbed dose by EBT3 film. <b>Methods</b> Beam energy was gradually increased in the clinical photon and proton energy ranges. Geant4 was used to calculate the difference in absorbed dose between EBT3 film and the same volume of water. The results were compared with the theoretical values. <b>Results</b> For photons and protons, the thresholds for absorbed dose with energy dependence were 100 keV and 11 MeV, respectively. The energy dependence was consistent with the theoretical values when the photon and proton energies were higher than the corresponding thresholds, and irrelevant to the theoretical values when energies were lower than the thresholds. The differences between the proton Bragg peak and 50% dose point and the actual positions were less than 1%. <b>Conclusions</b> For protons and photons with high energy, the energy dependence of absorbed dose in EBT3 film is negligible. For protons and photons with low energy, EBT3 film shows very different energy dependence of absorbed dose, which should be taken into consideration. The proton Bragg peak and 50% dose point measured by EBT3 film are basically the same as the actual positions.
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Objective@#To discuss the feasibility of applying home-made auto quality assurance (AQA) phantom in Cyberknife AQA test.@*Methods@#The same treatment plan for AQA test was designed in the Cyberknife treatment planning system. The AQA tests were performed under the same conditions using the home-made AQA phantom and the AQA phantom in the fourth-generation (G4) Cyberknife mode and the fifth-generation (VSI) Cyberknife mode, respectively, and each measurement was repeated five times to analyze and compare the differences in test results between the two phantoms.@*Results@#The total deviations of the home-made AQA phantom and the AQA phantom in the AQA test under the G4 Cy- berknife mode were (0.28 ± 0.12) mm and (0.28 ± 0.15) mm, respectively (P > 0.05); the test results under the VSI Cy- berknife mode were (0.46 ± 0.19) mm and (0.50 ± 0.07) mm, respectively (P > 0.05); the total deviations of all test results were smaller than 1.0 mm, which met the requirements of WS 667—2019 Specification for Testing of Quality Control in Ro- botic Arm Radiotherapy Device.@*Conclusion@#The test results of the home-made AQA phantom and the AQA phantom are consistent in the AQA test, and the home-made AQA phantom can be used for Cyberknife quality control.
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Objective:To estimate the induced radioactive 56Mn and its level of iron in heavy concrete shielding wall due to neutron activation during tumor proton therapy. Methods:A Geant4 program was adopted to build the model of a heavy concrete shielding wall in a proton therapy room, simulate secondary neutrons generated by 245 MeV proton beam irradiating water phantom. The statistical distribution of radionuclide 56Mn in shielding wall was calculated. The shielding wall was layered every 10 cm thickness, the dose equivalent rate of radionuclide 56Mn in the first three shielding walls was calculated. Results:Under the maximum beam irradiation conditions (1.872 × 10 10), the number of radionuclide 56Mn in the first three layers of shielding walls are 3.10×10 8, 1.60×10 8, 9.33×10 8. The ambient dose equivalent rate at a distance of 1 m from the treatment room are 2.13×10 -3, 8.82×10 -4, 9.10×10 -4 μSv/h, and the total ambient dose equivalent rate for the first three layers was 3.92× 10 -3 μSv/h. Conclusions:During proton therapy, the shielded walls near the central axis of the beam produce more induced radioactivity. The induced radioactivity produced by the neutron-activated iron element at the ahead of the shielding wall is the strongest, and decreases exponentially as the thickness of the shield wall increases.The induced radioactivity in front of the shielding wall of proton therapy room should be concerned.
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Objective:To investigate the radiation dose and its impact for human health after the Fukushima nuclear accident in Japan.Methods: The Fukushima nuclear accident caused by the Richter 9 earthquake of the east sea of Miyagi prefecture in Japan and huge tsunami was analyzed. And the detection results of the radiation dose from the nuclear accident that was named 7th grade event was evaluated whether existed effect for human health.Results: The radiation dose rate of the environment after this nuclear accident from the first nuclear power plant of Fukushima was increased, and the radioactive ranges of134Cs and137Cs mainly came from the leak of nuclear power plant were 100~500PBq and 6~20PBq, respectively. At the same time, the radioactive contaminations were found existed in water and foods, and they had posed a threat for marine organism.Conclusion: The detection result of nuclear accident of Fukushima has higher value for the evaluation of after-effect about human health, and the effects of Fukushima nuclear accident and its impact for life, property and ecological environment are worth pondering.
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Objective To study the step aceuracy of 252Cf neutron afterloading radiotherapy machine and the dose deviation caused by step deviation.Methods EBT3 film was used to measure the steps of the 252Cf neutron source,and then the center of each 252Cf neutron source was identified by measuring the optical density value by using the ImageJ software.Double ion chambersmethod was used to measure the dose deviation dlue to the 252 Cf neutron source position shift.Results 252 Cf neutron source step accuracy may amount to 0.01 mm using EBT3 film measurement,when 252Cf neutron source position deviation is less than 3 mm,the dose deviation is less than 2.5％.Conclusions The study on the step accuracy and position deviation of the 252Cf neutron source can provide a reference for the quality control standard of the 252Cf neutron afterloading radiotherapy machine.
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Objective To study the quality testing of dose delivery system of the active spot scanning proton and heavy ion accelerator,in order to provide the reference for the quality control of related equipment.Methods In the four therapy rooms,both 0.6 cc chambers and Gafchromic EBT3 films were used,respectively,to test the accelerator for dose reproducibility,dose linearity,dose stability,depth dose distribution,beam scanning position deviation and radiation field uniformity in each therapy room.Results Dose reproducibility variation coefficients are all less than 1.5％,dose linearity's maximum deviations less than 2％,dose stability's deviations less than 2％,depth dose distribution stability within 2％,beam scanning position deviation less than 1 mm,consistency of irradiation field's deviation less than 2 mm,and flatness within ± 5％.Conclusions The indicators about quality testing for the active spot scanning proton and heavy ion accelerator are all in line with the requirements of IEC standards draft.
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Objective To develop the method for testing the consistency of irradiation field produced by the active spot scanning proton and heavy ion accelerator.Methods Calibration of the EBT3 films were carried out with the calibrated ion beam to establish the dose calibration curve.According to the different proton and carbon ion energies (proton:94.29,150.68,212.62 McV;carbon ion:175.99,283.43,412.54 MeV/u),EBT3 films were located in the solid water phantoms in each therapy room,respectively.Finally,the irradiated EBT3 films were scanned and the radiation field size's deviation and flatness were analyzed.Results In different conditions,radiation field size's deviations were all less than 2 mm and the flatness parameters were all controlled below the 5％.Conclusions EBT3 films can be used to test the active spot scanning proton and heavy ion accelerator's radiation field uniformity.
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Objective To investigate the clinical effect of lumbar catheter drainage combined with intrathecal injection on patients with cerebrospinal fluid leakage and intracranial infection.Methods A retrospective study was conducted.One hundred and fifty-two cases with cerebrospinal fluid leakage and intracranial infection were selected as our subjects who were hospitalized in the First Hospital of Yuncheng from 2006 to 2014.The patients were divided into lumbar puncture + intrathecal group (A),lumbar (group B) and lumbar intrathecal large pool + group (group C) based on post-processing methods.A experimental data were recorded and compared in terms of the total efficiency of treatment,the therapeutically effective time,bacterial clearance and security differences.Results After treatment,the levels of white blood cells,protein,glucose and intracranial pressure were changed compared with that of before treatment in three group(P ＜ 0.01),but there was no significant difference among the three groups(P ＞ 0.05).The therapy periods in group A,group B and group C were (12.80 ± 2.25) d,(12.64 ± 2.00) d and (9.44 ± 1.50) d respectively and the difference was significant(F =25.94,P ＜ 0.05).Compared with Group C,the therapy periods in group A and B were significant different(t =2.769,2.854;P ＜ 0.05),but there was no significant difference between group A and B (t =0.119,P =0.908).The cases with success.effect was 45 (89.1％) in group A,53 (94.6％) in group B,46 (95.8％) in group C,and there was no significant difference among three groups (P ＞ 0.05).In terms of bacterial clearance rate,33 cases(68.75％) was in group A,35 cases(72.91％) in group C and 23 cases (41.07％) in group B and the effective rate in group A or C were higher than that in group B (x2 =9.478,10.63 ; P ＜ 0.05).Conclusion The methods of lumbar catheter drainage combinedwith intrathecal injection is proved with a high clinical value of therapy,effective treatment can effectively shorten the time and improve the overall treatment effect.
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Objective:To study the dose measurements methods of neutron andγ-ray for 252Cf neutron after-load radiotherapy machine. Methods:To measure the neutron-γmixed field with one ion chamber that have the similar sensitivities of neutron andγ-ray, another ion chamber that only have sensitivities for γ-ray, little sensitivity for neutron. Verification measurement results with calculated values. Results:Calculate key parameters, measure neutron andγ-ray dose rate at the position of 2.5cm, 5cm, 7.5cm and 10cm from the 252Cf, the Maximum deviation is-5.22%compared with calculated values. Conclusion:The method of twin ion chamber can measure the neutron andγ-ray mixed field dose.
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Objective To investigate the clinical efficacy of minimally invasive surgery for hypertensive intracerebral hemorrhage (HIH).Methods retrospectively analyzed the clinical data of 82 patients with HIH from March 2009 to May 2012,of43 patients in the observation group with minimally invasive surgery and 39 cases were treated with traditional craniotomy in control group.Comparing the two groups of patients with angiotensin system related indexes and 3 d internal pressure.Results The renin,angiotensin Ⅱ and aldosterone of observation group were (1.1 ±0.2) μg/(L · h),(56.7 ± 12.0) ng/L and (119.2 ± 15.6) ng/L respectively,while in control group were (2.1 ± 0.6) μg/(L · h),(77.4 ± 12.5) ng/L and (150.3 ± 22.4)ng/L respectively,there was a significant difference compared with the control group (t =6.74,8.93,5.61,respectively,P ＜ 0.05).The systolic blood pressure (SBP) preoperative and postoperative 1,2,3 days of observed group were (188 ± 12) mm Hg,(166 ± 10) mm Hg,(153 ± 9) mm Hg,(145 ± 9) mm Hg,while of control group were (189±17) mm Hg,(183 ±16) mm Hg,(179±15) mm Hg,(168±15) mm Hg(P＜0.05).The difference was statistically significant (F in group =19.41,P ＜ 0.05;F between group =21.33,P ＜0.05 ;F interactive group =17.56,P ＜ 0.05),and the observation changes of SBP were stable than the control group.Conclusion Minimally invasive operation in the treatment of HIH,can effectively control the systolic blood pressure levels.Patients recovered quickly,and of which the prognosis was good.
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ObjectiveTo observe and investigate the clinical effect and security of warfarin and aspirin in anticoagulant therapy of elderly patients with paroxysmal atrial fibrillation.MethodsOne hundred and ninety-seven elderly patients with paroxysmal atrial fibrillation were chosen and divided by random digits table method into two groups:control group (99 patients) with aspirin oral treatment;experimental group (98 patients) with warfarin oral treatment,the dose was adjusted according to the international normalized ratio (INR).The incidence of thrombosis embolism and adverse reactions of two groups were compared after 1-2 years following up.ResultsThe incidences of thrombosis embolism in control group [ 12.1％ ( 12/99 ) ] and experimental group [ 2.0％ ( 2/98 ) ] had significant difference ( P ＜ 0.05 ).There was no significant difference in the incidence of bleeding between control group[ 2.0％ (2/99)] andexperimental group [ 3.1％ (3/98) ] (P ＞ 0.05 ).The incidence of gastrointestinal reaction and allergic reaction of control group was 17.2％ ( 17/99 ),while the incidence of experimental group was 4.1％ ( 4/98 ),there was statistical difference (P ＜ 0.05 ).ConclusionsWith strictly control of INR in the range between 2.0 and 3.0,warfarin anticoagulant treatment for elderly patients with paroxysmal atrial fibrillation obtains definite clinical efficacy and fewer adverse reactions.It is worthy of clinical expansion and application.
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ObjectiveTo analyze the efficacy and safety of erythropoietin for anemia in patients with chronic heart failure.Methods66 cases with chronic heart failure were randomly divided into the observation group and the control group.The control group was treated with conventional anti-anemia iron treatment,and the observation group was taken erythropoietin therapy treatment on the basis of the control group.Both of the two groups were treated for 8 weeks continuously.ResultsThere were statistically significant differences between the two groups of patients after 8 weeks of treatment,cardiac function had improvement after treatment than before treatment (P ＜ 0.05 ).The observation group was significantly superior than the control group.The blood data in the two groups were compared,the Hb,RBC of the observation group were significantly increased compared with before treatment,the difference was significant (P ＜ 0.05).The RBC level did not change significantly in the control group before and after treatment.The electronic patient data in the two groups were compared,the LVEF,FS in the observation group and control group improved significantly compared with before treatment,but improvement of the observation group was significantly better than control group.The degree of improvement in the two groups were compared,the difference was significant( P ＜0.05).The SV,CO in the two groups were compared,it increasedsignificantly than before treatment,the difference was significant(P ＜ 0.05).The SV,CO before and after treatment in the control group didn't improve significantly.The E/A before and after treatment didn't improve significantly.The incidence of adverse drug reactions in the two groups showed no significant difference.ConclusionThe level of anemia had a direct impact on the degree of heart function classification.Following the usual treatment of heart failure,taking erythropoietin for anemia in patients with chronic heart treatment could significantly improve the treatment of patients with curative effect,with the advantages of safe,widely used for clinical application.
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Objective To study the effects of standardized-lifestyle intervention on the type 2 diabetic elder patients.Methods The study group enrolled 270 individuals with type 2 diabetes mellitus randomly by using the model of “Zhiji Health Care” and the software of the lifestyle and disease prevention system.Parameters were collected during a six month period for the evaluation,such as fasting plasma glucose(FPG),postprandial glucose(PPG),cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high density lipoprotein cholesterol(HDL-C),body mass(BMI),glycosylated hemoglobin(HbAlc),blood pressure,daily intake,total physical activity and effective physical activity and other indicators.Results After six months' standardized lifestyle intervention:(1)in the type 2 diabetic patients,the parameters of weight,BMI,waist circumference,systolic and diastolic blood pressure were significantly decreased(t values were:23.82,25.91,19.56,23.37 and 19.53,respectively,all P ＜ 0.01); FPG,PPG,HbA1c,TC,TG and LDL-C were significant decreased compared with that before intervention(t values were: 12.06,11.82,9.74,6.98,5.79 and 6.10,respectively,all P ＜ 0.0l).Meanwhile,HDL-C was significantly increased(t =2.51,P ＜ 0.05).(2)the total daily intake was significantly reduced compared with that before intervention.The effective exercise burden was significantly increased,compared with that before intervention(P ＜ 0.01).Conclusion Standard lifestyle management helps to control the blood glucose,blood pressurem,body weight and other risk factors,with reduction of complications and medical costs.
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Objective To analyze the influencing factors on hospitalization costs of osteoporosis hip fracture in elderly patients.Methods The hospitalization expenses of patients with osteoporotic hip fracture and influencing factors were analyzed by single factor analysis of variance and multiple regression analysis method in Beijing Ji Shuitan Hospital from 2009 July to 2010 December.Results Among 565 patients who underwent operation treatment,hospitalization costs of femoral neck fracture was (42 127±20 821) yuan,wherein the treatment fee was (27 283± 14 959) yuan,other expenses (expenses for medicine,examination and chemical examination) were (14 844 ± 8717) yuan.The above values of intertrochanteric fracture were (52 965± 15 901) yuan,(36 872±11 763) yuan and (16 093±7793) yuan,respectively.Treatment fee occupied 65％ of hospitalization expenses.Multivariate regression analysis of influencing factors of costs intertrochanteric revealed that femoral neck fractures hip arthroplasty,femoral intertrochanteric fracture,venous thrombosis of the lower extremity,and albumin infusion in perioperative period were correlated firmly with the increased hospitalization expenses and treatment expenses (P＜0.001).Comorbidities such as diabetes and anemia,perioperative complication such as delirium,cardiac disease,pulmonary embolism,pulmonary infection were related to the other higher expenses (P＜0.05).The longer of hospital stay resulted in higher cost of hospitalization (P ＜ 0.001).Conclusions Comorbidities and preoperative complications can increase other expenses.Osteoporotie hip fracture,with a high hospitalization cost,is a heavy economy burden.It is important to emphasize the disease prevention of both osteoporosis and aging chronic illness.
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Objective To research the molecular biology characteristics and transient expression in BHK-21 cells of E geue segment from Japanese encephalitis virus(JEV) and construct an eukaryotic expression vector pEGFP-C1-JEV.Methods E gene segment of JEV was amplified by RT-PCR,construct the recombinant vector pEGFP-C1-JEV,which could express EGFP label proteins.Transfect pEGFP-C1-JEV vector into BHK-21 via LipofectAMINETM 2000,to observe expressing of EGFP label protein and transcription of aim gene,and to check up localization and antigenicity of expressed E protein by Immunohistochemistry and Western blot.Results It showed that the recombinant plasmid pEGFP-C1-JEV was successfully constructed and transfected to BHK-21 cells,the normal expression of green fluorescent protein expression rate was higher.RT-PCR showed that gene transcription in BHK-21 and normal expression,expression protein was mainly distributed in the cytoplasm of BHK-21 cells and the envelope in,and can with guinea pig anti-JEV antibody binding.Conclusion pEGFP-C1-JEV vector in BHK-21 cells was normal expression and there were no effect on cell growth and morphology.Meanwhile,on eukaryotic antigens was good antigenicity.This research as a base foundation for E protein gene of JEV eukaryotic expression and function in vitro and applied research.
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Objective To evaluate the possibility and reliability of laparoscopic management of cholelithiasis merging extrahepatic and acalculous and benign obstructive jaundice. Methods Eleven patients with cholelithiasis merging extrahepatic and acalculous and benign obstructive jaundice who underwent laparoscopic management were retrospectively studied.Results Ten cases were successful with laparoscopic management,among the total,4 patients were underwent laparoscopic cholecystectomy (LC),6 cases were experienced LC and laparoscopic common bile duct exploration (LCBDE).One case was converted to open operation.No serious complications were observed.All the patients were cured after the operative treatment.None of the complications could be traced after follow-up for 6 months. Conclusions Cholelithiasis merging extrahepatic and acalculous and benign obstructive jaundice is a challenge to laparoscopic surgeons.Intraoperative diagnosis is very difficultly,but very important.It is better prognosis by careful and skilled operators and reasonable operative method to be chose.