Objective:To analyze the structure of supply and demand, the distribution status of essential drugs and low-cost drugs and the influencing factors in the distribution, and provide strategies and suggestions. Methods:The literature research, Delphi method, sampling survey and the other methods were used to analyze the effects of distribution pattern on the drug distribution in Henan, and then optimization measures were studied systematically. Results:The distribution mode of centralized purchasing drugs was the major influen-cing factor in the drug distribution rate and enthusiasm. Conclusion:The distribution of centralized purchasing drugs should stick to the principles of essential drugs priority and reasonable use in order to enhance the distribution enthusiasm of manufacturers. The distribution should base on the two-way choice distribution mode and combine with the mode of centralized distribution and independent choice, mean-while, the information technology should be improved to optimize dynamic management of distribution and promote the effectiveness of drug delivery.

Purpose:To analyse the dosimetric parameters measured by the silicon diode, and to describe the features of the dose distributions for small fields.Materials and Methods:P-type silicon diode with small volune and high sensitivity was chosen to measure the PDD,OAR and Sc,p at isocenter for circular fields of 5mm ～50mm in diameter used for stereotactic irradiation .The dosimetric data measured are evaluated by comparising with ones by other methods, such as ionization chamber and films,and ones in literature.Results:The values PDD of 10 and 30 fields at depth from 5cm～20cm are almost the same as those in reference 7 within ?0.6; The effective linear attenuation coefficient extrapolated to zero fiels size is 0.0510cm -1 for 6MV-X rays. The Sc,p value measured by diode and chamber(NE2571) are agread each other within variations of ?0.4% for large field size, but a great difference appears when the field size is 2 times smaller than the diameter of chamber. The Sc,p values by diode for field size of 12.5mm～27.5mm are agreed well with the results by Monte Carlo calculations. The OARs measured by diode are ageed well within 1mm with ones by films developed by ourself. The penumbras(90%～10%) measured by diode are coincidence with the results published.Conclusion:Due to the high dose gradients at the beam edge and the absence of lateral electron equilibrium for the smaller fields, the detector size and positioning are the most impostant factors influenced the measured results. Our practice shows that the silicon diode with diameter of 2mm or smaller is the best choice for the dosimetric date collection for beams used in X-ray stereotactic irradiation.

Objective To compare the dosimetric differences of permanent prostate braehytherapy utilizing 131Cs,125 I and 103 Pd seeds.Methods Twenty-five patients with T1-T2c prostate cancer who had previously implanted with 125I seeds were randomly selected in our study.The patients were re-planned with 131 Cs,125 I and 103 Pd seeds by using the Prowess Brachytherpay 3.1 planning system to the prescription doses of 115 Gy,145 Gy and 125 Gy,respectively.The seed strengths were 1.8 U,0.5 U and 1.8 U,respeetively. The prostate,prostatic urethra and anterior wall of the rectum were contoured on trans-rectal ultrasound ima ges.PTV was outlined based on the prostate volume with no margin applied.The attempted planning goals were that V100(tbe percentage volume of the prostate receiving at least 100% of the prescription doses)= 95%,D90 (the minimum percentage dose covering 90% of the prostate volume) ≥100% ,and prostatic ure thra UD10 (the maximum percentage dose receiving by 10% of the contoured urethra)≤150%.For the plan comparison,we also computed prostate V150,prostatic urethra UV120,rectum RV100,and the number of implan ted seeds and needles.The significance of the differences was tested using one way analysis of variance. Results The average V200 in the 103pd,125 I and 131 Cs plans were 28.7% ,20.9% and 19.6% (F=42.50, P =0.000) ;the average V150 were 51.9% ,42.1% and 39.4% (F=26.15,P =0.000) ;the average UV120 were 26.9% ,29.5% and 23.8% (F = 0.37,P =0.691) ; and the average rectum RV100 were 0.31 cm3, 0.22 cm3 and 0.19 cm3(F=0.43,P=0.652).For 103 Pd,124 I and 131 Cs,the average number of implanted seeds per cm3 prostate were 2.02,2.01 and 1.87(F = 1.92 ,P =0.154) ,and the average number of needles were 33.6,32.9 and 31.6(F=0.26,P=0.772). Conclusions Comparing to 124 I and 103 pd seeds used in permanent prostate brachytherapy ,131 Cs seeds has better dose homogeneity,and possible better sparing of the urethra and rectum,with comparable or less implanted seeds and needles.

[Objective]To study the methods and clinical results of infrared fluoroscopic navigation guiding system guided operations for the treatment of thoracolumbar fracture and analysis the common problems in the treatment of thoracolumbar fracture.[Method]A retrospective analysis was carried out in 56 cases with thoracolumbar fracture and dislocation from March 2003 to December 2006.There were 36 males and 20 females,ranging from 18-56 years(average 35 years).Segments involved:T11 10 cases,T12 13 cases,L1 21 cases,L29 cases,L3 3 cases.According to the classification of AO:there were 26 cases of type A,17 cases of type B,13 cases of type C.According to the classification of ASIA:there were 11 cases of type A,18 cases of type B,13 cases of type C,8 cases of type D,6 cases of type E,among which 35 cases had neurological disfunction symptom.Operation were performed under the suspection of computer assisted navigation system,32 cases underwent posterior decompession approach,withAF transpedicular screw internal fixation in thoracolumbar spine.Fifteen cases underwent anterior approach spondylectomy with bone graft and plate internal fixation.Other cases underwent conservative treatment.The vertebral stabilization and the struction of the three columns were reconstructed.[Result]The mean operati on time was 200 min,ranging from 160 to 300 min.The mean blood loss during operation was 1 000 ml ranging from 800 to 2 000 ml.All patients were followed up for 6 to 36 months(10 months on average).Neurological status improved to A ASIA grade in 4 cases,B grade 5 cases,C grade 11 cases,D grade 14 cases,E grade 22 cases.[Conclusion]The patient had remarkable improvement in clinical relief.In order to achive the best effect in the treatment of thoracolumbar fracture,correct treatments of primary trauma and injury type and appropriate management are necessary for the treatment of thoracolumbar fracture.Also,computer assisted navigation system enhances accuracy and further improves the safety of spine surgery.

Objective To study the symptoms, diagnosis, treatment and prognosis of colorectal malignant melanoma.Methods Six cases of colorectal malignant melanoma diagnosed and treated in our department between 1981 and 1996 were reviewed and underwent follow-up.Results All cases had masses that could be found near dentate line in digital examination and were black or brown in color. All patients underwent operations ,operations abdomino-perineal resection for 2 cases, post pelvic excision for 2 cases, enlarged local resection for 1 case and laporotomy for 1 case.Either lymph node metastasis or liver metastasis were found prior to or during operation. All patients died within 5～23 months after being diagnosed, with average survival time of 14.7 months.Conclusions Colorectal malignant melanoma was rare and was highly of malignant with tendency of early metastasis and poor prognosis. Radical surgery combined with chemotherapy, immunotherapy and biotherapy may be effective.

Objective To assess the effectiveness of balloon dilation and airway stenting performed under fluoroscopic guidance for the treatment of benign and malignant tracheal stenosis. Methods Under fluoroscopic guidance,balloon dilation and airway stenting were performed in 45 patients with tracheobronchial stricture. Of the 45 patients, malignant tracheal stenosis was seen in 37, including mediastinal nodal metastases (n = 14), esophageal carcinoma (n=13), lung carcinoma (n = 4), adenocarcinoma of bronchus (n = 3), lymphoma (n = 2) and laryngocarcinoma (n = 1), and benign tracheal stenosis was seen in 8, including endobronchial tuberculosis (n = 6), retrosternal thyroid adenoma (n = 1) and endotracheal intubation (n = 1). Airway stenting with serf-expandable metal stent was employed in 38 patients and balloon dilation in 7 patients. All the procedures were performed under fluoroscopic guidance. Results A total of 53 self-expandable metal stents was implanted in 38 patients. The clinical symptoms were immediately relived after the procedure in all patients except for one patient who died from choking of sputum. No stent migration was observed. Restenosis developed in 4 patients, which was successfully treated with repeated stenting and balloon dilation. Nineteen times of balloon dilation procedure were accomplished in 7 patients. Marked remission of clinical symptoms was seen in most cases. During a follow-up period (ranged from 0 to 124 months with a mean of 24.5 months) 31 patients died. Conclusion For both benign and malignant tracheal stenosis, balloon dilation with airway stenting performed under fluoroscopic guidance is a safe and efficient therapy with instant curative effect in relieving clinical symptoms.

Objective To measure and calculate the dose distribution (tissue absorbed dose) of mouth floor area while using 125I to treat sublingual gland carcinoma.Methods Phantom of head and neck was used to place the 125I radioactive seeds to simulate the sublingual gland carcinoma treatment.125I radioactive seeds of 29.6 and 25.9 MBq per seed were used as two groups,with 31 seeds in each group,and prescribed dose (peripheral matched dose) was 120 Gy.Thermoluminescence dosimetry (TLD) was used to measure the absorbed dose value in the simulated target and adjacent area.Gafchromic Eriochrome Black T (EBT) film was used to draw the dose distribution curve.Results Dose absorbed in the target area,target area center and the adjacent area one centimeter away from target reached 160 Gy,390-500 Gy,and 90-170 Gy,respectively.Dose of the skin ranged from 25 to 81 Gy,dose of mandible ranged from 7.9 to 67 Gy.No radiation cold spot was found.Conclusions 125I seeds could achieve an effective therapeutic dose distribution of the target area for sublingual gland carcinoma.Dose absorbed in the adjacent tissue is under safety limit.The radiation dose at mandible is lower,reducing the possibility of radiation damage to the bone.

Objective In order to evaluate the present status of Radiation Oncology in China,the Chinese Society of Radiation Oncology performed the 6th continent prefecture of China e survey.Methods Questionnaire forms were sent by mail,e-mail,telephone and FAX.Results By August 31 st,2011,there were 1162 radiation oncology centers.There was a total of 30985 employees,including 9895 doctors,1887 physicists,11689 nurses,6103 technicians and 1411 engineers.There were 1296 linear accelerators,286 telecobalt units,81 deep x-ray machine,1040 simulators,376 CT simulators,317 brachytherapy units,1427 treatment planning system,1041 dosimeters,410 X-knife,and 230 γ-knife (122 for head only,108 for head and body).There were 56847 beds for inpatients (4 centers did not report the number of beds).More than 58000 patients were treated per day ( no report from 9 centers ),and 569056 new patients were treated annually (no report from 38 centers).Conclusions Radiation oncology was developed rapidly in the last 5 years,either in personnel,equipment,and new techniques.They are still insufficient in proportion to our population.

Objective To discuss the value of high frequency ultrasound for the evaluation of subclinical rheumatoid arthritis.Methods Forty-four rheumatoid arthritis patientswho reached disease activity score (DAS28) clinical remis-sion were included.Ultrasound assess were carried out in all 68 joints,including bilateral temporomandibular joints,sternoclavicular joint,acromioclavicular joint,shoulder joint,elbow joint,wrist joint,1-5 metacarpophalangeal joints and the interphalangeal joint of the thumb,the 2-5 proximal interphalangeal joints,the 2-5 distal interphalangeal joints,hip,knee joint,ankle joint,tarsus joint,the 1-5 metatarsophalangeal joint,1-5 toeinterphalangeal joints.Analysis for the correlation between PD,GS score and gender,age,course of disease and clinical disease activity index were conducted.The pain visual analogue scale (VAS),time of morning stiffness,swollen joint count (SJC) and tender joint count (TJC),health assessment questionnaire (HAQ) score,erythrocyte sedimentation rate (ESR),and C-reactive protein (CRP) and rheumatoid factor (RF),anti cyclic citrullinated peptide (anti CCP) antibody,simplified disease activity index (SDAI),DAS28-CRP,DAS28-ESR were compared.Using Pearson and Spearman to analyze ultrasonic joint synovitis index score and clinical indexes,Student's t-test was employed to assess the significance of difference between two independent sample.Results Twenty-six patients reached/European League against Rheumatism (ACR/EULAR) 2011 remission,19 patients achieved ACR remission,and 3 patients achieved ultrasound remission.There was correlation between GS score and the course of disease and the number of swollen joints (r=0.602,0.470,P＜0.01).There was a positive correlation between ultrasound PD score and the patient's pain score,the total score of patients,ACR/EULAR2011,DAS28-ESR,DAS28-CRP (r=0.323,0.337,0.329,0.360,0.343,P＜0.05).The ultrasound PD score also had a positive correlation with CRP,ESR,time of morning stiffness (r=0.474,0.490,0.415,P＜0.01).Conclusion The subclinical arthrosynovitis can be detected by high frequency ultrasound in most rheumatoid arthritis patients at clinical remission.The PD ultrasound has advantage in evaluating RA activity over GS ultrasound.

It is difficult to reflect the properties of samples from the signal directly collected by the low field nuclear magnetic resonance (NMR) analyzer. People must obtain the relationship between the relaxation time and the original signal amplitude of every relaxation component by inversion algorithm. Consequently, the technology of T2 spectrum inversion is crucial to the application of NMR data. This study optimized the regularization factor selection method and presented the regularization algorithm for inversion of low field NMR relaxation distribution, which is based on the regularization theory of ill-posed inverse problem. The results of numerical simulation experiments by Matlab7.0 showed that this method could effectively analyze and process the NMR relaxation data.
Algorithms ; Humans ; Magnetic Resonance Spectroscopy