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ObjectiveThis study aimed to investigate the risk factors affecting the positive detection of Acinetobacter baumannii on the hands in medical staff of hospitals in Shanghai， and provide epidemiological evidence for the prevention and control of nosocomial infections. MethodsThe hands of doctors， nurses and care workers in key departments were sampled every quarter from 2018 to 2020 according toGB 15982‒2012 "Hospital Disinfection and Hygiene Standards". Separation and identification of A. baumannii were followed with sampling shortly. Information about the working years of sampling subjects， the hand sanitizers of which sampling subjects had used and the ingredients and actual using time of the hand sanitizers was collected while sampling. Finally， 709 samples were selected for this research after excluding the unqualified samples. ResultsThe positive detection of the hand samples was 7.05%. The logistic regression model suggested that the department， the time of using hand sanitizer， the hospital grade and occupational category were determinants of A. baumannii positive detection on hands in medical staff. The risk of A. baumannii positive detection in internal medicine department was 2.846 （95%CI：1.402‒5.776） times higher than that in intensive care unit while it was 3.357 （95%CI：1.349‒8.353） times higher in surgery department than that in intensive care unit. Regarding the use of hand sanitizer， the risk of A. baumannii positive detection was 3.076 （95%CI：1.534‒6.168） times higher in the staff used the hand sanitizer over 14 days than in the medical staff used the sanitizer within 14 days. The risk of A. baumannii positive detection in medical worker in secondary hospitals was 2.235（95%CI：1.088‒4.588）times than in tertiary hospitals. The risk of A. baumannii positive detection of care workers was 3.634 （95%CI：1.764‒7.484） times higher than nurses. ConclusionThe positive detection of hand samples was 7.05%. Department， the time of using hand sanitizer， the hospital grade and occupational category were determinants of A. baumannii positive detection on hands in medical staff. It was necessary to improve hand hygiene for medical staff， especially for care worker. Cleaning and disinfection need to be strengthened in internal department and surgery department.
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Objective To investigate the range of gray values of MRI local hyperintensity signals corresponding to the classification of partial tear of knee anterior cruciate ligament (ACL) under arthroscopy so as to evaluate its significance for diagnosis and treatment of acute partial ACL tear.Methods A retrospective analysis was conducted of 82 patients who had identical orthopaedic and MRI findings at Department of Orthopaedics and Traumatology,Shenzhen Baoan People's Hospital from January 2014 to June 2016.They were 49 males and 33 females;their ages ranged from 18 to 71 years,with an average of 39.6 years;27 left and 55 right knees were involved.Of them,67 were assigned into an ACL tear group in which both arthroscopic and MRI findings indicated diagnosis of acute ACL partial tear,and 15 into an ACL normal group in which both arthroscopic and MRI findings indicated diagnosis of normal ACL but injury to meniscus and/or articular cartilage.According to the arthroscopic grading,the 67 patients were rated as grade Ⅰ in 21 cases,as grade Ⅱ in 19,and as grade Ⅲ in 27.Software Photoshop CS4.0 was used to measure the gray values of local hyperintensity signals of the partial ACL tear in the MRI in the ACL tear group and the overall gray values of local hyperintensity signals of the normal ACL in MRI in the ACL normal group.The 2 groups were compared in terms of the range of gray values of MRI local hyperintensity signals and the proportion of ACL partial tear under arthroscopy.Results The range of gray values of MRI local hyperintensity signals in diagnosis of acute ACL partial tear was 20.24 ± 7.77 for the ACL normal group,67.54 ± 8.78 for the grade Ⅰ ACL partial tear,90.99 ± 7.21 for the grade Ⅱ tear,and 138.89 ± 32.40 for the grade Ⅲ tear,showing significant differences between the 4 groups and any 2 of the 4 groups as well (both P ＜ 0.05).The percentage of ACL partial tear under arthroscopy was 0 for the ACL normal group,0.22 ± 0.08 for the grade Ⅰ ACL partial tear,0.56 ± 0.08 for the grade Ⅱ tear,and 0.84 ± 0.064 for the grade Ⅲ tear,showing significant differences between the 4 groups and any 2 of the 4 groups as well (both P ＜ 0.05).Twenty-six patients (21 cases of grade Ⅰ and 5 ones of grade Ⅱ tear) received symptomatic treatment of the injury to the meniscus and/or articular cartilage without ACL reconstruction due to good function of residual ACL and stable knee joint.Forty-one patients (14 cases of grade Ⅱ and 27 ones of grade Ⅲ tear) underwent ACL reconstruction and treatment of co-morbidities because of poor function of residual ACL and instability of the knee joint.Conclusion The range of gray values of MRI local hyperintensity signals can be used to assist diagnosis and classification of acute ACL partial tear.
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Objective To explore the expression level and possible reasons of Tau protein in Beagle dog model of ischemic cerebral white matter(WM) demylination.Methods Sixteen adult Beagle dogs were divided into the sham operation group(A) and observation group B,C and D according to the completely random mumber table method,4 cases in each group.Different.degrees of cerebral ischemia animal models were established by 4-vessel occlusion(4-VO) method.The bilateral ventricle edge white matter (WM) was selected.The oligodendrocyte precursors(OPCs) were labeled by NG2.The mature oligodendrocytes(Ols) were labeled by CNPase.Tau,NG2 and CNPase were detected by using the immunohistochemical method.The expression level was quantified by the mean optical value.The correlation among Tau,NG2 and CNGase was analyzed by adopting the Pearson linear correlation analysis.Results The HE staining showed obvious changes of WM demylination after chronic cerebral ischemic.The scores after LFB staining in the group A,B,C and D were(0.75 ± 0.71) points,(1.38 ± 0.06) points,(1.63 ± 0.52) points and (1.88 ± 0.64)points.Compared with the group A,the scores in the group B,C and D were much higher(P＜0.05).Compared with the group A,the expression levels of Tau protein and NG2 were significantly increased(P＜0.05),while the CNPase expression level was significantly decreased(P＜0.05).The Pearson correlation analysis showed that Tau expression level was positively correlated with the NG2 expression level(r=0.277,P=0.006);Tau and NG2 were negatively correlated with the CNPase level(r=-0.303,-0.402,P=0.003,0.001).Conclusion The increase of Tau expression in Beagle dog model of ischemic cerebral WM demylination may be related to the differentiation dysmaturity of OPCs.
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Objective To evaluate the feasibility of a low-dose one-stop-shop cardiac CT imaging protocol with third-generation dual-source CT (DSCT). Methods Totally 23 coronary artery disease (CAD) patients were prospectively enrolled between March to September in 2016. All patients underwent an ATP stress dynamic myocardial perfusion imaging (MPI) (data acquired prospectively ECG-triggered during end systole by table shuttle mode in 32 seconds) at 70 kV combined with prospectively ECG-triggered high-pitch coronary artery angiography (CCTA) on a third-generation DSCT system. Myocardial blood flow (MBF) was quantified and compared between perfusion normal and abnormal myocardial segments based on AHA-17-segment model. CCTA images were evaluated qualitatively based on SCCT-18-segment model and the effective dose(ED) was calculated. In patients with subsequent catheter coronary angiography (CCA) as reference,the diagnosis performance of MPI (for per-vessel ≥50% and ≥70% stenosis) and CCTA (for≥50% stenosis) were assessed. Results Of 23 patients who had completed the examination of ATP stress MPI plus CCTA,12 patients received follow-up CCA. At ATP stress MPI,77 segments (19.7%) in 13 patients (56.5%) had perfusion abnormalities. The MBF values of hypo-perfused myocardial segments decreased significantly compared with normal segments [(93±22)ml/(100 ml·min) vs. (147±27)ml/(100 ml·min);t=15.978,P=0.000]. At CCTA,93.9% (308/328) of the coronary segments had diagnostic image quality. With CCA as the reference standard,the per-vessel and per-segment sensitivity,specificity,and accuracy of CCTA for stenosis≥50% were 94.1%,93.5%,and 93.7% and 90.9%,97.8%,and 96.8%,and the per-vessel sensitivity,specificity and accuracy of ATP stress MPI for stenosis≥50% and ≥70% were 68.7%,100%,and 89.5% and 91.7%,100%,and 97.9%. The total ED of MPI and CCTA was (3.9±1.3) mSv [MPI:(3.5±1.2) mSv,CCTA:(0.3±0.1) mSv]. Conclusion The third-generation DSCT stress dynamic MPI at 70 kV combined with prospectively ECG-triggered high-pitch CCTA is a feasible and reliable tool for clinical diagnosis,with remarkably reduced radiation dose.
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Humans , Computed Tomography Angiography , Methods , Coronary Artery Disease , Diagnostic Imaging , Heart , Diagnostic Imaging , Myocardial Perfusion Imaging , Prospective Studies , Radiation Dosage , Sensitivity and SpecificityABSTRACT
Objective:To investigate the prognosis of patients with liver metastasis or local recurrence after radical resection of rectal cancer,in order to provide reference for the further screening of high-risk patients for the precise therapeutic methods.Methods:The clinicopathological factor and follow-up data of 485 patients who underwent surgical treatment for rectal cancer from March 2005 to January 2016 were retrospectively analyzed.Including 75 liver metastasis and 32 local recurrence.The prognosis were compared between the patients with liver metastasis and with local recurrence.Results:The difference was statistically significant in CEA level,primary tumor position,surgical methods,tumor cell differentiation,tumor infiltration depth between liver metastasis and local recurrence after radical resection of rectal cancer (P＜0.05).The 1-,3-and 5-year overall survival rates were 76.6％,53.1％ and 18.8％ respectively of patients with liver metastasis,The 1-,3-and 5-year overall survival rates were 81.3％,62.5％ and 37.5％ respectively of patients with local recurrence,the difference was statistically significant(P＜0.05).Conclusion:There were different clinicopathological characteristics of patients between liver metastasis and local recurrence.The prognosis of patients with local recurrence was better than patients with liver metastasis.
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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.
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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.
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Objective To explore the method of target volume determination of postoperative 125I seeds interstitial brachytherapy in parotid gland carcinoma.Methods A total of 31 cases( 14 males and 17 famales) with primary parotid carcinoma who were treated in Peking University Hospital of Stomatology from Oct 2002 to Nov 2006.The patients' average age was 38.2 years.All patients underwent tumor resection and postoperative 125I seeds interstitial brachytherapy with 60 Gy matched peripheral dose.The spiral CT was performed for treatment plan and quality verification before and after the brachytherapy.The bone and muscle landmarks surrounding parotid were selected as reference for target volume determination.D90 of target volume and dose of organs at risk were calculated,while the target volume and D90 of target volume of verification were compared with that of treatment plan through quality verification.Results The target volume or D90 of target volume before and after treatment was not statistically different.D90 of target volume was more than 60 Gy.During 3 -7 years of follow-up,all patients had no recurrence.ConclusionsAccording to the follow-up results,the method used for target volume determination in this paper might be satisfied.
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Objective To evaluate the efficacy and toxicity of fractionated stereotactic body radiotherapy in treating patients with liver metastases. Methods From January 1997 to January 2007, 22 patients with liver metastases of total 33 lesions were treated with fractionated stereotactic body radiation therapy (SBRT). All patients were confirmed as unresectable and resistant to chemotherapy. The most common primaries were breast cancer in 12 patients and colorectal cancer in 5. Fifteen patients had metastases in the liver alone and 7 had concurrent metastases in other sites. Eighteen patients received one course of SBRT, and 4 patients got two courses. The median total dose was 40 (range, 30 - 60) Gy in 3 (range, 2 -6) fractions. Results All patients were followed up. The median follow up was 13.9 months (range, 5.0 -36. 4 months). The median size of the irradiated lesions was 2. 0 cm (range 1.0 -4. 3 cm) and the target volume was 3. 68 cm~3 (range 0. 45 - 77. 29 cm~3). The 1- and 2-year local control rate, overall survival rate and progression-free survival rate were 100% and 90%, 73% and 49%, 94% and 28%, respectively. No grade 3/4 SBRT related toxicities occurred. Conclusions SBRT, with high local control and tolerable complications, is an effective and safe treatment for liver metastases.
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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.
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Objective To investigate the influence of respiratory motion on target dose distribution in radiotherapy for patients with lung tumors. Methods The Big Bore Brilliance CT with bellows system was used to gain the 4DCT sets and respiratory frequency information of the patients. The moving ranges of the tumors in left-right (LR), anterior-posterior (AP) and cranial-caudal (CC) directions were measured from the center coordinate values of gross tumor volume of ten time-phase CT sets in the treatment planning sys-tem. Then a breathing model was used to simulate the tumor motions due to respiration. A 4-dimensional motion table was used to mimic the motion of lung tumor in beams-eye-view (BEV). A 2-dimensional semi-conductor beams measurement system was fixed to the table to measure the 2-dimensional dose distribution of static and dynamic targets using the treatment beams at gantry angle of 0°. Finally, the differences of the dose distribution between the static and moving phantom were compared and analyzed with the statistical soft-ware R. Results When the amplitude (half of the moving rang) in the CC direction was 1 cm, the passing ratio of relative dose difference ≤4% in one beam field was minimal (1.1%), and there was 58% maximal relative dose absence. The 4% passing ratios media in the CC direction were 94.7%, 79.4%, 58.6% and 37.1% in <0.25, 0.25-<0.50, 0.50- <0.75 and ≥0.75 mm amplitude (X<'2>=29.20,P=0.000), but were all similar in the AP and LR directions. The mean value of the relative dose change in the high dose area was smaller than the low dose area in the 89% beam fields. When only the CC direction was consid-ered, the 4% passing ratio of 3.6 s and 8.2 s period was 72% and 60%, respectively. Conclusions The amplitude in the CC direction is a factor impacting the dose distribution of the moving target. The influence of respiratory motion on high dose area is more than that on low dose area. When the other respiratory param-eters are fixed, the motion of long period has more influence on the dose than that of short period. Special at-tention should be paid to the patients with tumor of more than 0.5 cm amplitude in the CC direction when planning the intensity modulated radiotherapy.
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Objective To compare the characteristics of dose distribution between hypofractionated intensity modulated radiotherapy (IMRT) and hypofractionated stereotactic radiotherapy (SRT) plans in lung tumor and to select an optimal clinical approach. Methods SRT plans were designed for 16 patients with lung tumors who had received IMRT between April 2007 and April 2008. The dose distribution of target volume and normal tissues, conformal index (CI) and heteregenous index (HI) were analyzed using the dose-volume histogram (DVH) for the IMRT and SRT plans. Results The mean dose and equivalent uni-form dose of planning target volume (PTV) in IMRT were similar to those in SRT. SRT had significantly better CI and HI than IMRT (t = 2.77, P < 0.05 and t = - 4.38, P < 0.01 ). The mean lung dose of IMRT and SRT was (492.4 ±368.5) cGy and ( 310.0 ± 73.1 ) cGy, respectively ( t = 1.68, P > 0.05 ). The lung V20 of IMRT and SRT was 6.9% ± 2.1% and 4.2%± 1.9%, respectively ( t = 3.30, P < 0.01 ). No sig-nificant differences were found in the mean dose to the heart or the spinal cord between IMRT and SRT. Conclusions When PTV is less than 57 cm3 or the long diameter of tumor is less than 4.7 cm, hypofrac-tionated SRT has similar dose distribution to hypofractionated IMRT, while the lung dose was lower in the former.
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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.
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Objective To explore the real feeling and experience of the nurses when they changed their role into patients (in hospital), and find out the defect and disadvantage of nursing service, then we can identify the direction of how to improve our nursing service. Methods Six nurses who were hospital-ized for operations were interviewed about the feeling of being patients, before and after operations.The in-formation was collected and analyzed, then questions were raised up. Results The various feelings of 6 nurses before and after operation were got and 6 themes were summarized. Conclusions When the nurs-es have experienced the feeling of being patients, they understand the patients better, they consider that more thinking from another way could help to form good relationship between nurse and patient,"more un-derstand, more trust, less complain, less grumble".
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[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.
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Objective:Methods:To observe 213 cases of thick tongues in shape systematically by 30 kinds of thick tongues proposed in the Tongue Diagnostics and clinical observation.Results:After contrasting 213 patients with 200 cases of correlative disease,it has found that thick tongue is closely related to some syndromes and diseases,thus revealed that some diseases will cause blood stasis of superior vena cava,suffocating of the tongue lymph return-flow,increased power of the blood in the tongue tissue.Blood stasis in the tongue tissue,tissue edema and local exuded inflammatory pathological change in the tongue induced by the motion and sensory disturbance of the tongue muscle and nerve will lead to increased size and thickness of the tongue.Conclusion:The methods and data adopted in this paper provide significant reference in future study of tongue shape.
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Portal image verification (PIV) is one of the key actions in QA procedure for sophisticated accurate radiotherapy. The purpose of this study was to develop a PIV software as a tool for improving the accuracy and visualization of portal field verification and computing field placement errors. PIV was developed in the visual C++ integrated environment under Windows 95 operating system. It can improve visualization by providing tools for image processing and multimode images display. Semi-automatic register methods make verification more accurate than view-box method. It can provide useful quantitative errors for regular fields. PIV is flexible and accurate. It is an effective tool for portal field verification.
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Algorithms , Radiotherapy, Computer-Assisted , Methods , SoftwareABSTRACT
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.
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Objective To investigate methods and feasibility of percutaneous regional isolated hepatic perfusion combined with charcoal hemoperfusion(PRIHP-CHP).Methods Four out of 12 dogs underwent the procedure of routine transhepatic arterial infusion(TAI) as control group, 8 underwent PRIHP-CHP as experimental group. Adriamycin was used in our study, the concentration of plasma in hepatic vein and systemic vein was detected in both groups. Results All the procedures were successful in the PRIHP-CHP group eight, but 1 dog died because of air embolization. The average procedure duration for each was (132.3?15.3) minutes. The peak level of adriamycin concentration in hepatic vein and systemic in TAI were (3709.676?385.723) ng/ml and (1576.140?226.933) ng/ml respectively. In PRIHP-CHP, the peak level were (4653.420?430.204) ng/ml and (433.612?40.501) ng/ml. There were statistically significant differences between TAI and PRIHP-CHP (?