Objective To study the relationship between parameter settings in the intensity-modulated radiation therapy (IMRT) planning in order to explore the effect of parameters on absolute dose verification.Methods Forty-three esophageal carcinoma cases were optimized with Pinnacle 7.6c by experienced physicist using appropriate optimization parameters and dose constraints with a number of iterations to meet the clinical acceptance criteria.The plans were copied to water-phantem,0.13 cc ion Farmer chamber and DOSE1 dosimeter was used to measure the absolute dose.The statistical data of the parameters of beams for the 43 cases were collected,and the relationships among them were analyzed.The statistical data of the dosimetry error were collected,and comparative analysis was made for the relation between the parameters of beams and ion chamber absolute dose verification results.Results The parameters of beams were correlated among each other.Obvious affiliation existed between the dose accuracy and parameter settings.When the beam segment number of IMRT plan was more than 80,the dose deviation would be greater than 3％ ; however,if the beam segment number was less than 80,the dose deviation was smaller than 3％.When the beam segment number was more than 100,part of the dose deviation of this plan was greater than 4％.On the contrary,if the beam segment number was less than 100,the dose deviation was smaller than 4％ definitely.Conclusions In order to decrease the absolute dose verification error,less beam angles and less beam segments are needed and the beam segment number should be controlled within the range of 80.

Objective With the Monte Carlo method to recaleulate the IMRT dose distributions from four TPS to provide a platform for independent comparison and evaluation of the plan quality.These results wiU help make a clinical decision as which TPS will be used for prostate IMRT planning.Methods Eleven prostate cancer cases were planned with the Corvus,Xio,Pinnacle and Eclipse TPS.The plans were recalculated bv Monte Cado using leaf sequences and MUs for individual plans.Dose-volume-histograms and isodose distributions were compared.Other quantities such as Dmin(the minimum dose received by 99% of CTV/PTV),Dmax(the maximum dose received by 1%of CTV/PTV),V110%,V105%,V95%(the volume of CTV/PTV receiving 110%,105%.95% of the prescription dose),the volume of rectum and bladder receiving>65 Gy and>40 Gy,and the volume of femur receiving>50 Gy were evaluated.Total segments and MUs were also compared.Results The Monte Carlo results agreed with the dose distributions from the TPS to within 3%/3 mm.The Xio,Pinnacle and Eclipse plans show less target dose heterogeneity and lower V65 and V40 for the rectum and bladder compared to the Corvus plans.The PTV Dmin is about 2 Gy lower for Xio plans than others while the Corvus plans have slightly lower female head V50(0.03%and 0.58%)than others.The Corvus plans require significantly most segments(187.8)and MUs(1264.7)to deliver and the Pinnacle plans require fewest segments(82.4)and MUs(703.6).Conclusions We have tested an independent Monte Carlo dose catculation system for dose reconstruction and plan evaluation.This system provides a platform for the fair comparison and evaluation of treatment plans to facilitate clinical decision making in selecting a TPS and beam delivery system for particular treatment sites.

Objective To explore the relationship between disorders of lipid metabolism and avascular necrosis of femoral head after operation of femoral neck fracture .Methods 160 patients with a diagnosis of fresh femoral neck fractures treated with AO cannulated compressed screws in orthopedic department of our hospital from January 2007 to January 2012 were involved .All the patients were divided into two groups :ANFH or non ANFH group according to the features of femoral head .The levels of blood lipid were examined .Then ,Logistic regression was used to screening risk factors and evaluate the influence of blood lipid factors ac-cording to βrisk factor .Results The levels of TC ,TG ,LDL and Apo B in ANFH group were (5 .99 ± 1 .05)mmol/L ,(2 .63 ± 0 .85)mmol/L ,(4 .16 ± 1 .21)mmol/L ,(0 .99 ± 0 .28)g/L respectively ,which increased remarkably compared with the control group ;while HDL ,Apo A1 levels in the ANFH group were (0 .88 ± 0 .19)mmol/L ,(1 .20 ± 0 .17)g/L ,which was remarkably lower compared with the control group ,and there were statistically significant difference (P=0 .000) .Serum TC and LDL levels were risk factors impacted on postoperative ANFH .Conclusion Postoperative ANFH was related to disorders of lipid metabolism .Serum TC and LDL levels could be diagnostic values on postoperative ANFH .Early control of blood lipid levels may prevent the development of ANFH in patients treated with AO cannulated compressed screws .

Objective To compare the results of three dose verification solutions of esophageal carcinoma IMRT plans. Methods Seven esophageal carcinoma cases were planned with Pinnacle 8.0 h.The MATRIXX and Delta4 were chosen as the two-dimensional dosimetry and three-dimensional dosimetry.IMRT plans and Delta4 phantom plans were also recalculated by Monte Carlo. Gamma values were evaluated for MATRIXX and Delta4 with 3 mm/3% gamma criteria. For the comparison of Pinnacle, Delta4 and Monte gamma maps, the dose distribution in central plane, dose profiles and dose-volume histograms were used to evaluate the agreement. Results The gamma maps comparison show that with 3 mm/3% gamma criteria an over 98% pass ratio was obtained by MATRIXX measurement. A 94. 4% gamma pass ratio whicl.contains 4 fields gamma pass ratio lower than 90%, was obtained by Delta4 measurement. A 97.6% and 99. 8% gamma pass ratio was obtained between the Delta4 measurement and Monte Carlo simulation with 2 mm/2% and 3 mm/3% gamma criteria. The dose distribution in central plane and dose profiles from Pinnacle calculation were almost in agreement with both the Monte Carlo simulation and Delta4 measurement. The DVH plot have slightly differences between Pinnacle and Delta4 measurement as well as Pinnacle and Monte Carlo simulation, but have excellent agreement between Delta4 measurement and Monte Carlo simulation. Conclusions It was shown that all the three methods can be used very efficiently to verify esophageal carcinoma IMRT delivery, Delta4 and Monte Carlo simulation no data missed. The primary advantage of Delta4 is the fact it can measure true 3D dosimetry while Monte Carlo can simulate in patients CT images but not in phantom.

Objective To figure out the optimal parameters of a volumetric modulated arc therapy ( VMAT) plan for cervical and upper esophageal cancer by quality evaluation of VMAT plans with different parameters, and to provide a reference for the design of clinical VMAT treatment plan. Methods Ten patients with cervical esophageal cancer and ten patients with upper esophageal cancer were enrolled as subjects. The Nucletron Oncentra 4. 3 treatment planning system was used to generate plans for Elekta Synergy VMAT accelerator. Six VMAT plans were made with variation in the gantry angle ( 2°, 3°, and 4°), the maximum delivery time (80 s, 110 s, and 150 s), and the collimator angle (0° and 45°). The doses to the planning target volume and organs at risk were analyzed by paired t test. Results For cervical and upper esophageal cancer, the quality of VMAT plans with a collimator angle of 45° was better than those with a collimator angle of 0°(P=0. 003?0. 007). For cervical esophageal cancer, there was no significant difference in quality between VMAT plans with a maximum delivery time of 110 s or 150 s and those with a maximum delivery time of 80 s ( P>0. 05 );for upper esophageal cancer, there was also no significant difference in quality between VMAT plans with three different maximum delivery times ( P>0. 05 ) . For cervical esophageal cancer, the VMAT plans with a gantry angle of 3° had a better quality than those with a gantry angle of 2° or 4°(P=0. 010?0. 048). For upper esophageal cancer, the VMAT plans with a gantry angle of 3° had a better quality than those with a gantry angle of 4° ( P=0. 010?0. 048) . Compared with those with a gantry angle of 2° , the VMAT plans with a gantry angle of 3° had a slightly better dose distribution in the target volume ( P=0. 046 ) , but a slightly higher dose to lung tissue ( V25 and V30 , P=0. 007 and 0. 026) . Conclusions The optimal initial parameters of a VMAT plan for cervical and upper esophageal cancer are a collimator angle of 45°, a maximum delivery time of 80 s, and a gantry angle of 3°.

OBJECTIVE: To discuss about one patient with Alzheimer′s disease and urinary incontinence and to investigate the prescribing cascade between cholinesterase inhibitors and anticholinergic drugs further more. METHODS: Clinical pharmacists participated in a medication therapy management program aiming at one patient with Alzheimer′s disease and urinary incontinence. By doing this they successfully identified and interrupted a prescribing cascade. Then some constructive advices were provided to doctors and patients on the rational administration of drugs. RESULTS: The drug treatment plan was adjusted by clinical pharmacists and doctors after evaluating the benefits and risks about the use of cholinesterase inhibitors and anticholinergic drugs in the elderly patient with chronic disease. And this change directly led to a significant relief of urinary incontinence in the patient. CONCLUSION: The use of cholinesterase inhibitors in Alzheimer′s patients increases the risk of urinary incontinence, and at the same time additional use of anticholinergic drugs in the treatment of urinary incontinence can further damage the cognition.Therefore, clinical pharmacists and doctors should pay great attention to the prescribing cascade of cholinesterase inhibitors and anticholinergic drugs. To identify and interrupt prescribing cascades is important when clinical pharmacists and doctors are prescribing prescriptions for elderly patients with chronic diseases. They must work closely for the optimization of prescriptions and the improvement of medication safety in elderly patients.

Objective To investigate the resistant mechanism of Streptococcus pyogenes to ciprofloxacin and its homology.Methods Forty-eight isolates of Streptococcus pyogenes were collected from patients diagnosed with scarflet fever in districts of Beijing in March,2012 and MIC to ciprofloxacin and other 7 common antibiotics in clinic were detected by using blood M-H agar dilution method.Thirteen isolates,which have MICs≥4 mg/L against ciprofloxacin,were detected for mutations of Fluoroquinolone resistance genes gyrA,gyrB,parC,parE.At the same time,4 isolates,with MIC ≤ 0.25 mg/L against ciprofloxacin,were used for comparison.Homology analysis of 17 isolates from different areas of Beijing was performed by using the method of pulsed field gel electrophoresis.Results Sensitive rates of Streptococcus pyogenes to levofloxacin,ampicillin and penicillin were all 100％.The resistance rates to tetracycline,erythromycin and clindamycin were 91.7％ (44/48),91.7％ (44/48) and 89.6％ (43/48),respectively.MIC50 of ciprofloxacin,levofloxacin and moxifloxacin was 2 mg/L,1 mg/L and ≤ 0.25 mg/L,respectively ; MIC90 was 4 mg/L,2 mg/L and 0.5 mg/L,respectively.Of the 48 isolates of Streptococcus pyogenes,12 isolates showed the MIC at 4 mg/L,while one isolate has a MIC against ciprofloxacin at 8 mg/L,which isolated from Chaoyang district.Analysis of sequence of chromosome mediated fluoroquinolone resistance genes in those 13 ciprofloxacin non-susceptible isolates exhibited that there were 12 isolates that harbored Ser79Phe/Tyr mutation and 10 isolates harbored Ala121Val in parC gene.It is shown that one isolate contained Ser79Phe mutation in parC gene in the occurring of Ser371Leu mutation in parE gene for the first time,but there was no marked increase in ciprofloxacin MIC (MIC =4 mg/L).There were no mutations in gyrA and gyrB genes.The PFGE results demonstrated that the 17 tested isolates could be divided into 7 clones.The clone A isolates from Chaoyang,Daxing,Fengtai,Shunyi and Shijingshan district have a MIC ≥ 4 mg/L against ciprofloxacin,which covered 69.2％ of all MIC ≥4 mg/L isolates.The clone C isolates from Huairou district were MIC ≥4 mg/L isolates.B,D,E,F and G clones isolates come from different districts.Conclusions The mutation of parC gene was the main reason that contribute to the slightly increase of ciprofloxacin MIC in Streptococcus pyogenes isolated from Beijing.The PFGE analysis showed that there was a small scale prevalence caused by the infection of Streptococcus pyogenes in some districts.

Objective To construct the uniform electron density couch model (model A ED =0.25) and two components non uniform electron density couch model (model B FD =0.5and foam core=0.1) in the Monaco treatment planning system for the iBEAM(R) evo Extension 415,and to compare which model can better quantify the treatment couch influence on radiation dose.Methods Phantom was positioned in the center of the couch,the attenuation of the couch was evaluated with 6 MV for a field size of 10 cm× 10 cm.Dose measurements of couch attenuation were performed at gantry angles from 180.0° to 122.8°,using a 0.125cc semiflex ionization chamber (PTW),isocentrically placed in the center of a homogeneous cylindrical phantom.Each experimental setup was first measured on the linear accelerator and then reproduced in the TPS.By adjusting the relative-to water electron density (ED) values of the couch,the measured attenuation was replicated.The model accuracies of the model A and model B were evaluated by comparing the measured and calculated results at the minimum computational grid (2 mm) and maximum computing grid (5 mm),respectively.Results The maximum measured and calculated percentage deviation for the central phantom position was 4.01％.The couch model was included in the TPS with a uniform ED of 0.25 or a 2 component model with a fiber ED=0.5 and foam core ED=0.1.For model A and B under 2 and 5 mm voxel grid size,the mean absorbed dose with couch was reduced to 0.61％,0.84％,0.71％ and 0.92％from 2.8％ without couch.Conclusions Model A has a good agreement between measured and calculated dose distributions for all different voxel grid sizes and gantry angles.It can accurately describes the dose perturbations due to the presence of the couch and should therefore be used during treatment planning.

Objective To investigate the impact of intermittent porta hepatis occlusion on postoperative intra-hepatic recurrence of hepatocellular carcinoma.Methods We retrospectively reviewed the records of 335 patients who underwent partial hepatectomy.The patients were classified into 2 groups:(1) the study group (n=97):porta hepatis was occluded with intermittent Pringle maneuver with 2-3 cycles of clamp/unclamp time of 15 min/5 min,repeated 2-3cycles; (2) the control group (n=238):including using Pringle maneuver,preconditioning occlusion of porta hepatis and selective occlusion of portal blood inflow.Patients were followed-up in the Outpatient Department once every 2-3 weeks in the 1st year,and once every 3-6 weeks in the 2nd year with US/CT/MRI and serum AFP test.The mean duration of follow-up was 26.5 months.Results The perioperative mortality was 1.8％ (6/335).Tumour recurrence in the study group was 31.6％ and 48.4％ in the 1st and 2nd year,respectively.The recurrence rates were significantly higher,than the 21.4％ and 38.0％ in the control group (P＜0.05).To exclude the miscellaneous factors which were involved in intra-hepatic recurrence of HCC,we set up 3 criteria to include patients for subgroup analysis:tumor ≥5 cm; serum AFP decreased to normal level within 4 weeks; negative intra-operative US scan.The number of patients included were 79 and 155 in the study and the control groups,respectively.There were significant differences in recurrence rate between the study and the control groups in the 1st and 2nd year (29.1％ vs 18.7％,46.8％ vs 35.5％,P＜0.05).There were no significant differences in overall survival rate between the two groups.Conclusions Intermittent porta hepatis occlusion is a risk factor of postoperative intra hepatic recurrence of hepatocellular carcinoma.

Objective To evaluate the optimized conformal and IMRT plans for the upper esophageal carcinoma. Methods Eight patients with upper esophageal carcinoma underwent CT simulation.GTV was contoured on the CT image,referring the esophagogram and endoscopy simuhaneously,then CTV and PTV were also defined using the same criteria.Different conformal radiotherapy plans consisting of 3 fields(F),4F or 6F,IMRT plans consisting of 3F,4F,5F,7F,9F or 11F,and a simplified IMRT(s-IMRT)plan were designed for these patients.The minimum prescription dose that 95%of PTV volume received was 6000 cGy.Dose distributions of the PTV and OARs in different 3 DCRT and IMRT plans were compared and the optimized plans for the upper esophageal carcinoma were then recommended. Resuits Dose and volume parameters of PTV were similar among the 3DCRT plans(P＞0.05).4F 3DCRT plan reduced lung V20 as compared to 6F plan(P＜0.05),and mean lung dose(MLD)of 3F and 6F 3DCRT plans were higher than that of4F plan(P＜0.05).PTV D100 of 3F IMRT plan was lower than that of 9F and 11F plans(P＜0.05).IV of 4F IMRT plan was larger than that of 9F and 11F IMRT plans(P＜0.05).PTV dose and volume parameters of the 9F IMRT and 1 1 F IMRT were similar comparing with 5F.7F and s-IMRT plans,and OARs dose was also similar among IMRT plans(P＞0.05).PTV CI,D100,D95,V100 and V95 of the 4F 3DCRT plan were all lower than those of 5F,7F and s-IMRT plans(P＜0.05).5F,7F and s-IMRT plans reduced lung V20 as compared to 4F 3DCRT plan(P＜0.05).Conclusions For the upper esophageal carcinoma.4F 3DCRT plan is recommended among the 3DCRT plans.5F.7F and s-IMRT plans are recommended among the IMRT plans,which are superior than 4F 3 DCRT plan.