Objective To explore the dose rate response characterization of four kinds of dosimeters for clinical application.Methods Within the range of 100-600 cGy/min,the dose rate responses of the PTW 0.6 cm3 ion chamber,0.015 cm3 ion chamber,Matrixx Evolution 2D diode array and MapCHECK 2D diode array under the same measuring conditions were measured.The dose rate response of the PTW 0.6 cm3 ion chamber under different energy and working voltage were analyzed.Results All ionization chambe.r types of measured equipment showed certain dose rate dependence for 6 MV X-rays.All the differences were below 1％.The dose rate dependence disappeared for 15 MV X-rays.The 2D diode array had strong dose rate dependence and the response difference was about 2％.Conclusions It is necessary to test and analyze the dose rate response of the measured equipment in treatment technology with dose rate varying,in order to ensure the precision of daily calibration and dose verification.

Objective To assess the effect of vitamin D insufficiency on the quality of life in the elderly.Methods A total of 205 cases in health examination center of our hospital were randomly divided into elderly group (aged ≥ 60 years) and middle-aged g roup (aged 45-60 years).The SF-36 Form was adopted to investigate status of body and mental health.Serum 25 (OH)D3 levels were measured by enzyme-linked immunosorbent assay (ELISA).Serum 25 (OH) Ds ≤ 49.9 nmol/L was defined as vitamin D insufficiency. ResultsThere were 55 cases (53.9％) with vitamin D insufficiency and 16 cases (15.7％) vitamin D sufficiency in the elderly.The scores of vitamin D insufficiency group in the elderly were lower than of vitamin D threshold and sufficiency groups in fourdimensions,including physical function,physical role,body pain and general health.The scores ofvitamin D insufficiency group in the elderly were also lower than of vitamin D threshold and sufficiency groups in three dimensions,including social functioning,vitality and mental health (F=10.28,9.20,6.60,all P＜0.05).Serum 25(OH)D3 played more important role in scores of the quality of life in the elderly than other factors by stepwise multiple linear regression. ConclusionsThe vitamin D insufficient status widely exists in the elderly,and it might influence their quality of life.

Objective To study the vitamin D nutritional status in the elderly people from organs and institutions in Jinan urban district. Methods 564 cases were available from institutions enjoying a public medical care in Qianfoshan Hospital by stratified random sampling.The subjects aged (69.5±6.5)years were divided into two groups:60-74 years and≥75 years.The [25(OH)D] levels was measured by enzyme linked immunosorbent assay (ELISA).It was defined that [25(OH) D] levels ≥ 75 nmol/L was sufficient,50.0 74.9 nmol/L was critical,25.0-49.9 nmol/L were insufficient and ＜25 nmol/L was deficient.All data processing and statistical analysis were finished by SPSS13.0. Results The numbers of sufficient,critical,insufficient and deficient vitamin D in 564 subjects were 114(20.2％),180(31.9％),234(41.5％) aud 36(6.4％),in subjects aged ≥75years were 13(9.8％),36(27.3％),70(53.0％) and 13(9.8％),and in subjects aged 60-74 years were 101(23.4％),144(33.3％),164 (38.0％),23 (5.3％),respectively. There was significant difference in the vitamin D nutritional status between the two age groups (x2=19.097,P＜0.01 ).The numbers of sufficient,critical,insufficient and deficient vitamin D in the 246 male were 57 (23.2％),91(37.0％),86 (35.0％％) and 12(4.9％),in the 318 female were 57(17.9％),89 (28.0 ％ ),148(46.5 ％ ) and 24(7.5 ％ ).The percentages of insufficient and deficient vitamin D in the female were higher than in the male (x2 =11.445,P＜0.01 ). Conclusions Insufficient and deficient vitamin D nutritional states are common in the elderly people from organs and institutions in Jinan urban district and are increasing with age,especially in the female.

Objective To investigate the set-up error of CR in total body irradiation localization and lung shielding.Methods TOR 18FG software was employed to measure the image quality of images at kV and MV levels.The clinical processes were established and the positioning error was analyzed.Results The low contrast resolution and spatial resolution of MV level images were much worse than those at kV level in the condition of total body irradiation,but the image at MV level could be used to identify the high contrast tissues and employed in total body irradiation.The longitudinal errors were (0.50 ± 1.65) cm for left lung and (1.16 ± 1.56)cm for right lung in A P direction,while (1.12 ± 2.22)cm and (0.41 ± 2.16)cm respectively in PA direction.The errors of lateral were (0.81 ± 1.19)cm for left lung and (0.43 ±1.20)cm for right lung in AP direction,while (0.31 ± 1.64)cm and (0.55 ± 1.49)cm respectively in PA direction.Conclusions Application of CR in total body irradiation could make positioning in treatment much easily and reduce the localization errors.

OBJECTIVE: To retrospectively evaluate the effect of locking compression plate (LCP) combined with scaled cancellous bone graft on postoperative nonunion of humeral shaft fracture. METHODS: A total of 19 cases with postoperative nonunion of humeral shaft fracture were collected from Department of Orthopaedics, Affiliated Hospital, Xiangnan University between August 2005 and January 2009. There were 12 males and 7 females, aging 28-59 years with the mean age of 36 years. All patients were treated with LCP fixation combined with scaled cancellous bone graft. The key points of the operation were as follows: beck-median or lateral approach, protection of the radial nerve and ulnar nerve, removal of the cicatrix, reopening of humeral canal, and limited periosteum striping. For minimally invasive plate osteosynthesis technique, length of LCP was appropriate, 3-4 locking screws at least were used on either stump, and double cortices were penetrated with locking screws and treated with scaled cancellous bone graft. RESULTS: All the fractures healed with a mean period of 7.2 months (from 6 to 8 months). Two cases showed temporary radial nerve palsy after the operation, which gradually recovered 3 and 6 weeks, respectively after appropriate treatment. Shoulder and elbow functions were somewhat impaired in 7 cases, but the dysfunction could not influence daily living. Infection, screw loosening, blade plate breakage, and other complications were not found. CONCLUSION:The integrity of locking screws and plate prevents screw breakage and plate loosening. The combination of autoallergic cancellous bone graft and scaled decorticating technique can improve healing of humeral shaft fracture.

BACKGROUND:Active surgical treatments are preferred for elderly hip fractures. Individual fixation method is chosen according to fracture site, type, age and whether there are basic diseases in internal medicine, which plays an important role in the successful treatment of elderly hip fractures.
OBJECTIVE:To explore the effects of optimized surgical treatment on osteoporotic hip fracture in the elderly.
METHODS: Totally 176 patients with osteoporotic hip fracture were treated by different methods between January 2000 and January 2012, including 63 males and 113 females, with a mean age of (76.7±6.3) years. Out of the 84 cases of interchanteric fracture, seven cases were treated with conservative methods, 34 cases were treated with dynamic hip screw internal fixation, 18 cases were treated with cannulated screw internal fixation, seven cases were treated with anatomical plate internal fixation, 12 cases were treated with bipolar femoral placement, and six cases were treated with total hip arthroplasty. Out of the 92 cases with femoral neck fractures, 40 cases were treated with bipolar femoral placement, 37 cases were treated with total hip arthroplasty and 15 cases were treated with cannulated screw internal fixation. Modified Harris hip function scores were used to evaluate the therapeutic effects of different treatment methods. Complications were observed.
RESULTS AND CONCLUSION:Seventy-six cases of interchanteric fractures and 85 cases of femoral neck fractures were fol owed-up for 8-26 months with an average of (5.7±1.3) months. Three cases suffered from post-operative infection, and one case died due to cardio-pulmonary failure in 10 days after operation. Both intraoperation and postoperative complications included femoral head cutting, intraoperative fracture, internal fixation and prosthetic loosening, postoperative fracture, avascular necrosis of femoral head, coxa vara, legs shorten, and delayed fracture healing. The incidence rates of complications in patients undergoing bipolar femoral placement and total hip arthroplasty were significantly lower than those treated with conservative methods, dynamic hip screw internal fixation, cannulated screw internal fixation, and anatomical plate internal fixation (P<0.05). The outcomes of the treatment according to Harris scoring criterion were better in patients treated with bipolar femoral placement and total hip arthroplasty than in patients treated with conservative methods, dynamic hip screw internal fixation, cannulated screw internal fixation, and anatomical plate internal fixation (P<0.05). No significant differences were found in the incidence rate of complications and Harris scores among patients treated with conservative methods, dynamic hip screw internal fixation, cannulated screw internal fixation, and anatomical plate internal fixation (P>0.05). No significant differences were found in the incidence rate of complications and Harris scores between patients treated with bipolar femoral placement and total hip arthroplasty (P>0.05). These findings indicate that the treatment of osteoporotic hip fracture in the elderly can achieve satisfactory results if the comprehensive therapies are given. Bipolar femoral placement and total hip arthroplasty are preferred for elderly femoral neck fractures.

Objective To conduct a computer simulation to evaluate the discrepancy between the cumulative doses calculated by four-dimensional computed tomography (4DCT) images and 4DCT scans (for real-time respiratory motions) due to the patient's irregular breathing.Methods A series of digital phantoms were generated from a patient's 4DCT images to simulate 4DCT images and 4DCT scans (for real-time respiratory motions) resulting from various irregular breathing curves.A six-field intensity-modulated radiotherapy plan was generated.Two cumulative doses in the target were calculated.The first one, named Dall, was calculated by tracking the point displacements in the target manifested on the 4DCT images;the second one, named D4D, was calculated based on the point displacements along the whole breathing motion during 4DCT scanning.Dose discrepancy between D4D and Dall was calculated to evaluate the correlation between breathing pattern and dose discrepancy in the target.Results The dose discrepancy in the target was correlated with mean motion excursion and the standard deviation of motion excursion.ΔDmin(ΔD99) in the target increased from 2.39%(2.04%) to 11.91%(5.24%) as the mean motion excursion increased from 5 mm to 15 mm, and increased from 5.93%(2.15%) to 14.65%(5.01%) as the standard deviation of motion excursion increased from 15% to 45% of the mean motion excursion.When the mean period increased from 3 s to 5 s or the standard deviation of period increased from 10% to 40% of the mean period,ΔDmin(ΔD99) in the target was greater than 6.0%(2.0%), but less than 9.0%(3.0%).When the target diameter was 2 cm, 3 cm, and 4 cm,ΔDminΔD99) in the target was 11.88%(5.50%), 6.91%(2.42%), and 7.53%(3.62%), respectively.Conclusions There is a large discrepancy between the cumulative doses calculated using 4DCT images and 4DCT scans (for real-time respiratory motions) when the patient has irregular breathing.This dose discrepancy depends on mean motion excursion and the standard deviation of motion excursion, but has little relationship with mean period, the standard deviation of period, and tumor volume.

Objective To measure the actual absorbed dose of the target in the QUASAR Respiratory Motion Phantom using the CyberKnife Synchrony Respiratory Tracking System, and to evaluate the effect of density heterogeneity on the absorbed dose of tumor gross target volume ( GTV ) . Methods Nine groups were obtained by making different patterns of QUASAR phantom:rib thickness of 0, 20, and 50 mm, and motion amplitudes of 0, 10, and 15 mm. The nine groups were treated with static computed tomography (CT) in different time phases of four-dimensional CT (4DCT) plan, with the same beam and number of monitor units, and the 4D accumulated dose was calculated. The doses of static and 4D plans were calculated using Ray-tracing and Monte Carlo algorithms, and the absorbed doses of GTV in the nine groups were measured at the same time. Results There were a decrease in calculated absorbed dose of GTV and an increase in deviation between the planned and actual dose, with the increases in simulated rib thickness and motion amplitude. Conclusions The density heterogeneity has an impact on the absorbed dose of GTV. Both static CT and 4DCT plan can evaluate the absorbed dose of GTV in case of small rib thickness and motion amplitude, and 4DCT plan with Monte Carlo algorithm may be the optimal method for evaluation of the absorbed dose of GTV in case of large rib thickness and motion amplitude ( deviation<3%)

Objective To evaluate the effect of the discrepancy of the dose calculation results of different algorithms upon the CyberKnife lung tumor treatment plan,and assess the impact of tumor volume and location on the dose calculation results. Methods Thirty-two cases of lung tumors were treated with MultiPlan 5.2.1 planning system of CyberKnife VSI.Ray Tracing and Monte Carlo algorithms were adopted to calculate the dose distribution, and then the calculation results were statistically compared between two algorithms. Results For the enrolled cases,the calculation results of these two algorithms demonstrated that the deviation range of prescription dose coverage of planning target volume (PTV),conformal index,new conformal index and uniformity index were 0.93%~68. 80%, 0.87%~17. 21%,-212.38%~8. 27% and 0%~15. 17%, respectively. Conclusions In the CyberKnife treatment of lung tumors, the volume and location of tumors exert significant impact on the discrepancies of the dose calculation results of different algorithms. The smaller tumor volume and longer beam heterogeneity path are likely to generate a greater discrepancy. It is recommended to adopt or refer to the calculation results of Monte Carlo algorithm to deliver corresponding treatment.

Objective:To investigate the relationship between serum albumin(SA)levels and left atrial thrombosis(LAT)in elderly patients with nonvalvular atrial fibrillation(NVAF), and to evaluate the clinical value of SA in predicting LAT in elderly NVAF patients.Methods:Clinical data of 180 elderly patients with NVAF undergone transesophageal echocardiography(TEE)in our hospital were retrospectively analyzed.According to whether there was thrombosis in the left atrium, patients were divided into the thrombus group(n=42)and the non-thrombus group(n=138). Logistic regression was used to analyze factors related to left atrial appendage thrombosis in NVAF patients.The receiver operating characteristic(ROC)curve was used to evaluate the value of serum albumin levels in predicting LAT formation in elderly NVAF patients.Results:The duration of AF was longer in the thrombus group than in the non-thrombus group(all P<0.05). C-reactive protein(CRP)levels and platelet(PLT)counts were higher, and SA levels and the international normalization ratio(INR)were lower in the thrombus group than in the non-thrombus group(all P<0.05). The left atrial diameter(LAD)was larger in the thrombus group than in the non-thrombus group( P<0.05). Multiple Logistic regression analysis showed that the duration of AF and CRP levels were independent risk factors for LAT( P<0.05), and SA levels and INR were independent protective factors for LAT( P<0.05). ROC curve results showed that the area under the curve(AUC)of SA in predicting LAT was 0.778(95% CI: 0.711-0.837, P<0.001). Conclusions:Low serum albumin levels are closely related to LAT in NVAF patients and can be regarded as a predictor of LAT.Serum albumin levels should be monitored in clinical practice to reduce the incidence of stroke events in patients with AF.