OBJECTIVES: To analyze bone mass distribution and the factors affecting bone mass in a general Chinese Han cohort undergoing physical examinations at our center. METHODS: We retrospectively collected the data of bone mineral density (BMD) measurements from 30 599 healthy Han Chinese adults (age≥20 years) who underwent dual-energy X-ray absorptiometry scans at our hospital from July, 2013 to July, 2023. Basic parameters including height, body weight, and gender were recorded, and descriptive statistics and correlation analyses were performed using R software. RESULTS: In this cohort, the male individuals had a mean peak BMD of 1.00±0.12 g/cm² in the lumbar vertebrae, 0.94±0.14 g/cm² in the femoral neck, and 0.99±0.13 g/cm² in the total hip, significantly higher than the values in the female individuals [0.99±0.12 g/cm² in the lumbar vertebrae (P=0.022), 0.79±0.11 g/cm² in the femoral neck (P<0.001), and 0.88±0.11 g/cm² in the total hip (P<0.001)]. In the overall cohort, the BMD values of the lumbar spine and femur decreased with age after reaching their peak levels. There was a positive correlation between BMD value and body mass index (BMI) in both male and female individuals. The 2013-2014 period recorded the lowest BMD values in the lumbar, hip, and femoral neck, which tended to increase steadily in the following years (2015-2023). CONCLUSIONS Our data suggest that the BMD values vary among different populations, and future multi-center studies using more accurate BMD detection technology are warranted to capture the variation patterns of BMD with demographic characteristics of specific populations.
Humans ; Bone Density ; Absorptiometry, Photon ; Male ; Female ; Retrospective Studies ; Osteoporosis/diagnostic imaging* ; Adult ; Middle Aged ; Lumbar Vertebrae/diagnostic imaging* ; China/epidemiology* ; Femur Neck/diagnostic imaging* ; Aged ; Beijing/epidemiology* ; Young Adult

Objective:To establish the basic procedures of the application of optical surface monitoring system (OSMS) in the deep inspiration breath hold (DIBH) radiotherapy for patients with left sided breast cancer and compare the performance of OSMS and cone-beam CT (CBCT) in the determination of the set-up errors of DIBH radiotherapy for patients with left sided breast cancer.Methods:Twenty patients with left sided breast cancer received DIBH radiotherapy. Through the registration of CBCT images with the planning CT images, and the registration of OSMS radiography images with the outer contour of the body surface, translational set-up errors and rotational errors were determined along the lateral-medial ( Rx), superior-inferior ( Ry) and anterior-posterior ( Rz) directions. Pearson correlation analysis was performed to evaluate the correlation of the set-up errors determined by two methods, and Bland- Altman plot analysis was used to assess the coincidence of these two methods. Results:Two methods were positively correlated. The Rz volume was 0.84, 0.74 and 0.84 in the x, y and z directions, and 0.65, 0.41 and 0.54 in the Rx, Ry and Rz directions, respectively (all P<0.01). The 95% CI of agreement were within preset 5 mm tolerance (-0.37-0.42cm, -0.39-0.41cm, -0.29-0.49cm ) in x, y and z directions for two methods. The 95% CI of agreement were within preset 3 ° tolerance -2.9°-1.4°, -2.6°-1.4°, -2.4°-2.5°in Rx, Ry and Rz directions for two methods. The system errors of 20 patients with left sided breast cancer receiving DIBH radiotherapy were <0.18cm and the random errors were <0.24cm. Conclusions:OSMS is equivalent to CBCT in the determination and stimulation of set-up errors for patients with left sided breast cancer receiving DIBH radiotherapy. The combination of CBCT and OSMS is a safe and reliable method.

Objective:To explore the clinical effect of multidisciplinary cooperative intervention in improving self-management and improving fluid retention in the elderly patients with chronic heart failure.Methods:Totally 130 cases of the elderly patients with chronic heart failure from January to December 2018 were enrolled and were divided into control group and observation group with 65 cases randomly. The control group received routine nursing instruction and telephone follow-up. The observation group was given multidisciplinary team guidance to patients self-management in addition to routine nursing instruction and telephone follow-up. After 3 months, the self-management and fluid retention of the two groups were compared.Results:After 3 months of intervention, the scores and total scores of the observation group in the four dimensions of drug management, diet management, psychological and social adaptation management, symptom management were 19.43±0.71,11.51±0.59,19.07±0.65,25.24±1.31, 72.65±7.16, the control group was 11.09±3.40, 6.05±1.71, 12.73±2.49, 15.72±4.18, 46.35±7.83. The scores and total scores of the observation group were better than those of the control group ( t value was 4.835-13.727, all P < 0.05).After intervention for 3 months, the proportion of severe edema, moderate edema and mild edema in the observation group was 4.61% (3/65), 13.85% (9/65), 81.54% (53/65), respectively, and the control group was 38.46% (25/65), 52.31% (34/65) and 9.23% (6/65) respectively. The degree of fluid retention in the observation group was better than that in the control group ( Z value was -2.373, all P < 0.05). Conclusion:Multidisciplinary cooperative intervention can improve self-management and improve fluid retention in elderly patients with chronic heart failure.

Objective To retrospectively analyze the setup error in radiotherapy of somal tumors and body metastases using the ExacTrac X-ray portal image,and to evaluate the feasibility and effectiveness of 6D setup error correction in body radiotherapy.Methods The translational and rotational setup errors were calculated by registering the bony structures on the ExacTrac X-setup images to that of the digitally reconstructed setup images,and the corresponding residual errors were calculated together.Results The translational and rotational setup errors in the x (left-right),y (superior-inferior),z (anterior-posterior) and Rx (sagittal),Ry (transverse),Rz (coronal) directions were(2.27±2.02) mm,(4.49±2.52) mm,(2.27± 1.37) mm and (1.02 ± 0.73) °,(0.67 ± 0.68) °,(0.76 ± 0.84) °,respectively.The residual translational and rotational setup errors in the x(r),y(r),z(r) and Rx(r),Ry(r),Rz(r) directions were(0.27±0.48)mm,(0.37±0.45)mm,(0.22±0.30)mm and (0.17±0.33)°,(0.14±0.34)°,(0.16± 0.28) ° respectively.Conclusions Besides the translational setup errors,a certain amount of rotational setup errors exist in radiotherapy of somal tumors and body metastases.By using the 6D setup error correction of the ExacTrac system,a translational less than 0.4 mm and rotational setup errors less than 0.2° could be achieved.

Objective To evaluate the effect of setup errors upon the target area and the organs at risk (OAR) during radiotherapy for prostate cancer.Methods Twelve prostate cancer patients receiving treatment in the recent 1 year were randomly recruited in this study.The position of each patient was verified by using cone beam CT (CBCT) for 6-10 times during the treatment.In treatment planning system (TPS),the isocenter position was moved along the setup errors with averaging error value (Plan_A) and each CBCT value (Plan_F).The dose distribution was recalculated without changing the beam setting,weight factors and monitor units (MUs).The dose difference was statistically compared between the simulation and original plans (Plan_O).Results For clinical target volume (CTV) D95,there was a significant difference between Plan_A and Plan_O (P =0.008),whereas no significant difference was observed between Plan_F and Plan_O.There were significant differences between Plan_F and Plan_O,Plan_A and Plan_O (P=0.004,and 0.041) for the planned target volume (PTV) D95.For OAR,rectal V60,Dmax,left femoral V20,Dmax and right femoral Dmax significantly differed between Plan_F and Plan_O (P=0.026,0.015,0.041,0.049,0.003).However,only left femoral Dmax significantly differed between Plan_A and Plan_O (P=0.045).The movement in the superior-inferior (SI) direction was significantly correlated with the changes in the rectal V40,V50 and V60 and PTV D95 (r=-0.785,-0.887,-0.833,0.682).The movement in the anterior-posterior (AP) direction was significantly associated with the variations in the bladder V20,V30,V40,V50 and V60(r=-0.945,-0.823,-0.853,-0.818,-0.774).The evaluation indexes of all normal tissues in the re-plan could meet the clinical requirements.However,the volume of target prescription volume had different levels of deficit,and the deficit of Plan_F was greater than that of Plan_A.Conclusions The simulation results of averaging into the TPS underestimates the effect of daily setup errors on the dose distribution.The effect of setup errors on the dose distribution in target area is greater than that of normal tissues.Y-direction errors are more likely to cause the variations of the rectal and PTV dose,and the errors in the z-direction are inclined to cause the changes in the bladder dose.

Objective To establish a novel method of describing the off-axis ratio (OAR) characteristics of the flattening filter-free (FFF) beam.Methods The OAR curves at a depth of 1.5,5,10 and 20 cm were measured for Varian Edge,Elekta VersaHD and Tomotherapy using the water tank.The second derivatives of the OAR in the positive and negative directions were calculated.The center of the line connecting the maximum and minimum second derivatives was defined as the field edge.The distance between the left and right field edges was defined as the dosimetric field size.The OAR curve within the 80％ of dosimetric field size was fitted using the gaussian function and the fitting parameters were adopted to describe the shape of OAR.Results The calculated field size error was less than 0.11 cm and the central axis position error was less than 0.05 cm.The fitting correlation coefficient was greater than O.998.The fitting maximum error of OAR curve did not significantly alter with the depth,whereas slightly increased over the increased field size.The maximum error for a field size of 10,20,30 and 40 cm was 0.49％,0.67％,1.25％ and 2.52％,respectively.Conclusions A method which can independently and accurately describe the OAR characteristics of FFF photon beam is established for the first time,which can calculate the field size of FFF beam and fit the OAR curve of FFF beam using the gaussian function.

OBJECTIVE:To establish a method for the residual simultaneous determination of methanol,alcohol,dichlorometh-ane,n-hexane,tetrahydrofuran and benzene in tosufloxacin tosylat. METHODS:Headspace GC was performed on the capillary col-umn with 6%cyanopropylphenyl-94%dimethylpolysiloxane(DB-624)as fixative lipid,temperature programmed,the inlet temper-ature was 180 ℃,detector was flame ionization detector with temperature of 300 ℃,carrier gas was high purity N2 at a flow rate of 1.5 mL/min,split ratio was 10:1,headspace equilibrium temperature was 100℃,equilibrium time was 40 min,headspace sam-ple volume was 10 mL,and the headspace sample volume was 1 mL. RESULTS:The linear range was 178.3-1782.7 μg/mL for methanol (r=0.9991),301.2-3012.1 μg/mL for alcohol(r=0.9997),33.81-338.10 μg/mL for dichloromethane(r=0.9993), 18.02-180.22 μg/mL for n-hexane(r=0.9991),43.26-432.58 μg/mL for tetrahydrofuran(r=0.9991)and 0.1268-1.2681 μg/mL for benzene(r=0.9991);limits of quantification were 0.31,3.00,0.67,0.02,0.005,0.10 μg/mL,limits of detection were 0.15, 1.51,0.22,0.01,0.001,0.05 μg/mL;RSD of precision test was no higher than 3.1%;RSDs of methanol and n-hexane in stabili-ty and reproducibility tests were no higher than 5%;recoveries were 93.72%-102.20%(RSD=3.1%,n=9),90.10%-101.79%(RSD=4.0%,n=9),97.07%-103.11%(RSD=2.0%,n=9),92.38%-103.83%(RSD=3.9%,n=9),95.44%-103.62%(RSD=2.8%,n=9),and 94.00%-104.73%(RSD=4.1%,n=9). CONCLUSIONS:The method is rapid,sensitive,accurate,and suitable for the residual determination of methanol,alcohol,dichloromethane,n-hexane,tetrahydrofuran and benzene in tosufloxacin tosylat.

Objective To investigate the correlation between setup error and couch position error in radiotherapy.Methods A total of 25 patients with thoracic and abdominal tumors who recently finished image-guided radiotherapy were randomly selected.The data on couch position during treatment were obtained through the record validation system, and then the couch position error was calculated.The Pearson correlation analysis was used to investigate the correlation between setup error and couch position error during treatment.Results In the ≥5 setup errors among the 25 patients, the correlation coefficient between random setup error and random couch position error was 0.83(P=0.00), and the correlation coefficient between systematic setup error and systematic couch position error was 0.36(P=0.11).Conclusions In radiotherapy, the random setup error is highly correlated with the random couch position error, while a moderate or low correlation exists between the systematic setup error and the systematic couch position error.

OBJECTIVETo investigate the dosimetric benefit of 4D-CT in the planning target volume (PTV) definition process compared with conventional PTV definition using general margin in radiotherapy of lung cancer.

METHODSA set of 4D-CT images and multiphase helical CT scans were obtained in 10 patients with lung cancer. The radiotherapeutic plans based on PTV determined by 4D-CT and in addition of general margin were performed, respectively. The 3D motion of the centroid of GTV and the 3D spatial motion vectors were calculated. The differences of the two kinds of PTVs, mean lung dose (MLD), V5,V10,V15,V20 of total lung, mean heart dose (MHD), V30 and V40 of heart, D99 and D95 were compared, and the correlation between them and the 3D spatial motion vector was analyzed.

RESULTSThe PTV4D in eight patients were smaller than PTVconv, with a mean reduction of (13.0 ± 8.0)% (P = 0.018). In other two patients, whose respiration motion was great, PTV4D was larger than PTVconv. The mean 3D spatial motion vector of GTV centroid was (0.78 ± 0.72)cm. By using 4D-CT, the mean reduction of MLD was (8.6 ± 9.9)% (P = 0.037). V5, V10, V15, V20 of total lung were decreased averagely by (7.2 ± 10.5)%, (5.5 ± 8.9)%, (6.5 ± 8.4)% and (5.7 ± 7.4)%, respectively (P < 0.05 for all). There was a significant positive correlation between PTV4D/PTVconv and the 3D spatial motion vector of the GTV centroid (P = 0.008). A significant inverse correlation was found between D994D/D99conv and the 3D spatial motion vector of the GTV centroid (P = 0.002). D994D/D99conv, (MLDconv-MLD4D) /MLDconv, total lung (V5conv-V54D)/V5conv, total lung (V10conv-V104D)/V10conv, (MHDconv-MHD4D)/MHDconv, heart (V30conv-V304D)/V30conv were inversely correlated with PTV4D/PTVconv (P < 0.05 for all).

CONCLUSIONS4D-CT can be used to evaluate the respiration motion of lung tumor accurately. The 4D-CT-based PTV definition and radiotherapeutic planing can reduce the volume of PTV in patients with small respiration motion, increase the intra-target dose, and decrease the dose of normal tissue sequentially. For patients with large respiration motion, especially those more than 1.5-2 cm, this method can avoid target miss, meanwhile, not increase the dose of normal tissue significantly.

Four-Dimensional Computed Tomography ; methods ; Humans ; Lung ; physiopathology ; Lung Neoplasms ; radiotherapy ; Movement ; Radiometry ; Radiotherapy Planning, Computer-Assisted ; methods ; Respiration ; Tomography, X-Ray Computed ; methods

Objective To analyze the influencing factors of cone-beam CT (CBCT) imagine registration in lung cancer. Methods From Mar. 2007 to Dec. 2007, 20 patients with lung cancer were treated with IGRT. The imagines of CBCT were collected from 6 to 19 fractions during the patients' radiotherapy. To compare the difference of set-up errors between the two groups according to the distance from the lesion in lung to the centrum. At the same time, CBCT imagines from the first, middle and the last fraction of these patients' radiotherapy were registrated in bone and grey methods by four doctors. The difference of set-up errors between different doctors and registrated methods were compared. Results The mean values of set-up errors were ＜2 mm in the two groups without significant difference (x:-1.31mm vs 0. 10 mm (t=0. 07,P=0.554);y:1.24 mm vs 1.37 mm (t=0. 05,P=0. 652);z: - 1.88mm vs -1.26mm (t= -0. 12,P=0.321)). The mean values of set-up errors were ＜ 1.3 mm in four doctors and registrated methods without significant difference, for bone registration,x: -0. 05 mm, -0. 01 mm,0. 05 mm, -0.12 mm and -1.31 mm ( F=-0.01,P=0.887) ;y:0.56 mm,0.35 mm,0.51 mm and 0.43 mm (F= -0.01,P=0.880);z: -1.16 mm, -1.20 mm, -0.88 mm and -1.03 mm (F= -0.04,P=0. 555 ), for grey registration ,x: -0.32 mm, -0.341 mm, -0.395 mm and - 0.37 mm(F=-0.01, P=0.874);y:0.34 mm,0.54 mm, -0.04 mm and 0.27 mm (F= -0.03,P=0.622);x:-1.12 mm,- 1.15 mm, - 1.13 mm and - 1.04 mm (F=0. 00,P=0. 812). Conclusions With the same registrated box and imagine quality, the location of the lesions in lung, registred methods and different doctors are not the influencing factors for CBCT imagine registration.