Impact of accelerator operating errors on γ passing rate during dose verification of volumetric modulated arc therapy for pelvic tumors / 中华放射肿瘤学杂志

Objective:To investigate the impacts of gantry rotation angle errors, monitor unit (MU) errors, collimator and multi-leaf collimator (MLC) position errors upon the γ passing rate of dose verification in volumetric modulated arc therapy (VMAT).Methods:Ten patients with rectal cancer and 10 patients with uterine tumors were selected. The operating errors of accelerator parameters were introduced during the VMAT execution. By comparing the γ passing rates during dose verification between the simulating and original plans, the impact and sensitivity of the operating errors of each accelerator parameter on γ passing rate were analyzed.Results:When the γ criteria were set as 3%/3 mm, 3%/2 mm and 2%/2 mm, the γ passing rate decreasing gradient was less than 7.0% after the introduction of gantry rotation angle, MU and collimator position errors, respectively. However, after the reverse, opposite, and co-directional motion errors of the MLC blades on both sides were introduced, the γ passing rate decreasing was less than 19.13 %, 18.53%, 0.19 %; 19.87%, 20.01%, 0.42 % and 23.11%, 23.45%, 0.65 % for absolute dose verification, respectively.Conclusion:During VMAT, the reverse and opposite motion errors of MLC blades exert more significant effect on the γ passing rate compared with the gantry rotation angle errors, MU errors, collimator position errors and co-directional motion errors of the MLC blades. When the γ criteria of 3%/3 mm, 3%/2 mm and 2%/2 mm are adopted, the impact of accelerator operating errors upon the γ passing rate is strengthened in sequence. Therefore, when performing dose verification for a specific patient, appropriate γ criteria should be chosen and absolute dose verification should be taken as the reference index to evaluate the consistency between the calculated and measured dose distribution.

Clinicopathologic features and risk factors for lymph node metastasis of papillary thyroid carcinoma with chronic lymphocytic thyroiditis / 中华普通外科杂志

Objective To summarize clinicopathologic features of papillary thyroid carcinoma (PTC) coexistent with chronic lymphocytic thyroiditis (CLT) and investigate risk factors for lymph node metastasis.Methods The medical records of 4 264 consecutive papillary thyroid carcinoma patients who received surgical treatment from Oct 2013 to Oct 2015 in Peking Union Medical College Hospital were reviewed.The diagnoses was confirmed by histopathological tests.Univariate analysis was performed to identify specific clinicopathologic features of PTC with CLT.Univariate and multivariate analysis were performed to determine whether each clinicopathologic feature was an independent risk factor for lymph node metastasis.Results In all 4 265 cases,there were 3 059 papillary thyroid microcarcinoma (PTMC) (71.7％),1 010 PTC patients (23.7％) with CLT.909 female patients (90％),624 cases with multifocal lesions (61.8％),422 cases with extra-thyroid extension (41.8％),429 cases with lymph node metastasis (42.5％),and 133 cases with metastatic lymph nodes(LNs) ≥6 (13.2％).The median age was 43 years old and median tumor size was 0.8 cm.Patients with CLT were more females (90.0％ vs.70.2％;P ＜ 0.001),younger median age (43 vs.44 years;P =0.001),and lower incidence of lymph node metastasis (42.5％ vs.50.9％;P ＜0.001).CLT was not associated with tumor size,multifocal lesions,extra-thyroid extension and metastatic LNs≥6 (0.8 cm vs.0.7 cm,61.8％ vs.62.9％,41.8％ vs.42.1％ and 13.2％ vs.14.8％,respectively,all P ＞ 0.05).In multivariate analysis,CLT was an independent protective factor for lymph node metastasis (OR =0.713,95％ CI 0.609-0.835,P ＜0.001).In PTC patients with lymph node metastasis,CLT was not associated with lymph node metastasis number (3 vs.3,P =0.300).Conclusions Chronic lymphocytic thyroiditis was an independent protective factor for papillary thyroid carcinoma patients with lymph node metastasis.But in patients with lymph node metastasis,the metastatic number didn't decrease.

The dosimetric impacts of accelerator operation error on the volumetric modulated arc therapy for cervical cancer / 中华放射医学与防护杂志

Objective To investigate the dosimetric effect of accelerator gantry rotation angle errors, collimator and multileaf collimator ( MLC) leaf position errors on volumetric-modulated arc therapy ( VMAT) for cervical cancer. Methods A total of 10 patients with cervical cancer were selected. The plan. Trail file of each clinical plan was extracted from the Pinnacle3 V9. 2 planning system of USA Philips, then the operating parameters of tach control point were read and modified by Matlab programs, and thus the operating error of the accelerator was simulated. Results In this paper, it was discovered that systematic accelerator gantry rotation angle errors, systematic collimator position errors and systematic MLC shift errors which led to the maximum changes of the PTV dose limit were 0. 16％, 0. 46％ and 0. 57％, respectively, and the maximum changes of the dose limit of organs at risk ( OAR) were 0. 38％, -1. 32％ and -0. 44％, respectively. When the systematic MLC gap width errors were ± 0. 5, ± 1 and ± 2 mm, respectively, the maximum changes of PTV dose were 2. 11％, 3. 04％ and 6. 03％, respectively, while the maximum changes of the OAR average dose were 2. 17％, 3. 92％ and 7. 97％, respectively. Furthermore, the dose limits of PTV and OAR showed a strong linear correlation with MLC open or close errors(t=21. 201～90. 562,P<0. 05). If actual errors of each parameter of accelerator were introduced, the maximum changes of PTV and OAR dose limits were 0. 16％ and 1. 30％, respectively, and conformity index (CI) and homogeneity index (HI) were barely changed. Conclusions No significant effect was found for systematic accelerator gantry rotation angle errors, systematic collimator position errors and systematic MLC shift errors for cervical cancer VMAT patients. However, there is a high sensitivity to dose distribution for MLC open or close errors. Therefore, it is necessary to pay more attention on the quality control of the accelerator running in particular MLC position errors to ensure the therapeutic accuracy.

Relationship between body mass index and the incidence risk and severity of papillary thyroid microcarcinoma / 国际外科学杂志

Objectives To evaluate the relationship between body mass index (BMI) and the incidence risk of papillary thyroid microcarcinoma (PTMC).Methods This retrospective study included 1210 PTMC patients who underwent surgery between November 2013 and October 2014 in Peking Union Medical College Hospital,China Academy of Medical Science.A population-based 1∶1 matched case-control study was conducted,and each PTMC patients was matched with one who received thyroid function and ultrasonic to confirm that there was no disease in the thyroid.The clinical profiles of these patients were collected.According to Guidelines for Prevention and Control of Overweight and Obesity in Chinese Adults,all subjects were divided into three groups:underweight (BMI ≤ 18.5 kg/m2),normal(18.5 kg/m2 ＜ BMI ≤ 23.9 kg/m2),overweight (24.0 kg/m2 ＜ BMI ＜ 27.9 kg/m2) and obese group(BMI≥28.0 kg/m2).The relationship between BMI and PTMC incidence risk was analyzed by casecontrol study.Univariate and multivariate logistic regression analysis was applied to analyze the relationship between BMI and PTMC severity.Results The BMI of PTMC patients was significant higher than in normal control [(24.30 ±3.33) kg/m2 vs (23.31 ± 3.50) kg/m2,P ＜ 0.0001].Compared with BMI normal group,the incidence risk of PTMC in underweight group was significantly lower (OR =0.449,95 ％ CI:0.270-0.747),which is higher in overweight and obese group (OR =1.559,95％ CI:1.261-1.928;OR =2.059,95％ CI:1.501-2.823).Histopathological review of 1210 PTMC patients with surgical resection revealed.The proportions of underweight,normal,overweight and obese group of the patients with extrathyroid extension (3.1％,48.0％,36.7％,12.2％) have significant differences with those in the patients whose tumor are limited to the thyroid (0.7％,45.2％,36.0％,18.1％) (P =0.0090).The proportions of 4 group of the patients with multiple lesions (3.2％,49.0％,35.6％,12.2％) were significantly differences to those in the patients with single lesion (0.8％,43.3％,38.7％,17.2％) (P =0.0050).Multivariate analysis showed that underweight is a protective factor of extrathyroidal extension (OR =0.219,95 ％ CI:0.051-0.932;OR =0.279,95 ％ CI:0.085-0.935) and mulifocality,and obese is an independent risk factors(OR =1.556,95％CI:1.047-2.312;OR =1.764,95％CI:1.204-2.584).Conclusions This study identified that the incidence risk of PTMC is positive related with BMI.In PTMC patients,obesity increases the risk of mulifocality and extrathyroidal extension.Attention should be paid to the effect of obesity on the incidence risk of PTMC and the diagnosis and treatment in clinical practice.

Clinical and pathological feature of papillary thyroid microcarcinoma with diameter ≤0.5 cm / 中华内分泌外科杂志

Objective To evaluate the clinical and pathological feature,as well as risk factors of lymph node metastasis (LNM) and high-volume LNM (hvLNM) in papillary thyroid microcarcinoma (PTMC) with di ameter ≤0.5 cm.Methods PTMC patients who received surgical treatments in Peking Union Medical College Hospital from Nov.2013 to Nov.2014 were reviewed.Patients were allocated into the ≤0.5 cm group and (0.5-1)cm group according to tumor diameter.Clinical and pathological features were assessed and compared.Risk factors of LNM and hvLNM were also assessed through univariate and multivariate analysis.Results 1414 patients were enrolled,of which 315 patients (22.3％) were in the ≤0.5 cm group.76 LNM (24.1％) and 9 hvLNM (2.9％) were detected in the ≤0.5 cm group.There was significantly less capsule invasion (14.3％ vs 25.0％,P＜0.05),LNM (24.1％ vs 39.8％,P＜0.05) and hvLNM (2.9％ vs 7.9％,P＜0.05) in ≤0.5 cm group than in (0.5-1)cm group.In univariate analysis,patients aging ＜40 years old were more likely to have LNM than those older than 40(38.0％ vs 20.1％,P＜0.05),while male patients tended to have more LNM than female (32.4％ vs 21.9％,P=0.073).No risk factors were identified for hvLNM.In multivariate analysis,multifocality and younger than 40 years old were the independent risk factors of LNM (OR=2.082 and 2.899,P＜0.05),while male tended to be the independent risk factors of LNM (OR=l.807,P=0.058).No independent risk factors was identified for hvLNM.Conclusions A certain proportion of PTMC patients are with tumor diameter ≤0.5 cm,who have lower risk of LNM and hvLNM.Dynamic observation may be an option,especially in older ≥40 years old),unifocal and female patients.

Related factors analysis for lymph node metastasis in papillary thyroid carcinoma: a series of 2 073 patients / 中华外科杂志

Objective@#To investigate the related factors for lymph node metastasis (LNM), especially for high volume LNM (>5 metastatic lymph nodes) in papillary thyroid carcinoma (PTC).@*Methods@#The medical records of 2 073 consecutive PTC patients who underwent lobectomy, near-total thyroidectomy or total thyroidectomy with ipsilateral or bilateral central lymph node dissection in Department of General Surgery, Peking Union Medical College Hospital from November 2013 to October 2014 were reviewed. Clinical and pathological features were collected. Univariate and multivariate analysis were performed to identify the related factors for LNM/high volume LNM.@*Results@#In all 2 073 patients, LNM and high volume LNM were confirmed in 936 (45.15%) cases and 254 (12.25%) cases respectively. In univariate analysis, large tumor size, young patients (<40 years), male were associated with both LNM and high volume LNM. In multivariate analysis, tumor size >2.0 cm, young patients (<40 years), male were independent related factors of LNM (OR=5.262, 95% CI: 3.468 to 7.986; OR=2.447, 95% CI: 2.000 to 2.995; OR=1.988, 95% CI: 1.593 to 2.480, respectively, all P=0.000) and high volume LNM (OR=6.687, 95% CI: 4.477 to 9.986; OR=2.975, 95% CI: 2.224 to 3.980; OR=2.354, 95% CI: 1.737 to 3.191, respectively, all P=0.000). In 1 414 PTMC patients, a similar result was also demonstrated.Compared with young patients (<40 years), old patients (≥60 years) had lower incidence of LNM (25.47% vs. 52.24%, χ2=62.903, P=0.000) and high volume LNM (1.89% vs. 13.18%, χ2=37.341, P=0.000). Additionally, old patients also had lower risk of both LNM (OR=0.316, 95% CI: 0.194 to 0.517, P=0.000) and high volume LNM (OR=0.142, 95% CI: 0.034 to 0.599, P=0.000).@*Conclusions@#The tumor size was the main related factor for both LNM and high volume LNM in PTC. The treatment should be more active in patients with tumor size >2 cm with consideration of higher incidence and risk for LNM and high volume LNM. Young patient was another important related factor for LNM and high volume LNM. In PTMC, old patients had lower incidence and risk for both LNM and high volume LNM. Dynamic observation or less surgical extent could be an option for these patients.

Quality control of linac in daily volumetric-modulated arc therapy / 中华放射肿瘤学杂志

Objective To verify the daily delivery accuracy of volumetric-modulated arc therapy (VMAT) and achieve the process quality control (PQC) of linac using statistical process control (SPC)technology.Methods The log files of all treatments were taken out from the linac system.An in-house software which created by Matlab 7.14 was used to analyze the daily parameters accuracy and the mechanism and dose delivery accuracy of the linac for each VMAT,and an daily evaluation report was automatically created for the linac.The stability of the linac and the deviation of the delivery accuracy for various cancer sites were also analyzed.To achieve the process quality control of hnac using SPC technology,the control limit of each parameter was calculated by Johnson alternation and the single value control charts were drawn.Results 76 patients mainly with nasopharyngeal carcinoma,cervical carcinoma,rectal cancer and laryngeal cancer,got the treatment daily with VMAT technology,and a total of 2 446 arcs were delivered by the linac in continuous 16 days.The gantry angle error,y and x collimator position error,MLC leaf position error and dose delivery error were 0.49°,0.09 mm,0.38 mm,0.31 mm,0.05 MU,respectively.Compare to the nasopharynx,uteri,rectal and larynx cancer,it can be seen that the variation factors of dose delivery and gantry angle errors for various cancer sites were higher,which was 8.10％ and 4.54％,respectively.Through the process quality control of the linac,it was found that all the parameters were in control.While some abnormal points arose (the error was greater than UCL),and the ratio of the gantry angle which was out of control (0.45％) was the highest in all parameters.Conclusions linac delivery accuracy could be monitored and verified during the whole VMAT treatment for each patient,and the daily running condition of linac could be monitored.Through the introduction of SPC technology and the control charts,the process quality control of linac in VMAT could be achieved.It is a financial and valid method for the daily quality assurance of linac.

Investigation of CT numbers correction of kilo-voltage cone-beam CT images for accurate dose calculation / 中华放射肿瘤学杂志

Objective To study CT numbers correction of kilo?voltage cone?beam CT (KV?CBCT) images for dose calculation. Method Aligning the CBCT images with plan CT images, then obtain the background scatter by subtracting CT images from CBCT images. The background scatter is then processed by low?pass filter. The final CBCT images are acquired by subtracting the background scatter from the raw CBCT. KV?CBCT images of Catphan600 phantom and four patients with pelvic tumors were obtained with the linac?integrated CBCT system. The CBCT images were modified to correct the CT numbers. Finally, compare HU numbers between corrected CBCT and planning CT by paired T test. Evaluate the image quality and accuracy of dose calculation of the modified CBCT images. Results The proposed method reduces the artifacts of CBCT images significantly. The differences of CT numbers were 232 HU, 89 HU, 29 HU and 66 HU for air, fat, muscle and femoral head between CT and CBCT respectively (P= 0?? 39,0?? 66,0?? 59,1).The differences of CT numbers between CT and CBCT was reduced to within 5 HU. And the error of dose calculation with corrected CBCT images was within 2%. Conclusions The CT numbers of corrected CBCT are similar with plan CT images and dose calculations based on the modified CBCT show good agreement with plan CT.

Effect of Touqing capsule associated with acupuncture at Fengchi on cervical spondylosis / 国际中医中药杂志

objective To evaluate the clinical effect of touqing capsule associated with Fengchi on the vertebral artery type of cervical spondylosis(CSA)in the attack stage.Methods A total of 100 patients with CSA, according to the doctor order, were randomly divided into a control group and a treatment group respectively, with 50 patients in each. The control group was treated with acupuncture therapy, the treatment group was additionally treated with Touqingcapsule on the basis of the control group, and both groups were treated for 20 days. The hemodynamics was detected by transcranial doppler, the change of TCM syndrome integral was observed before and after the treatment, and the clinical efficacy was evaluated.Results After treatment, the treatment group dizziness (1.10 ± 0.33 vs. 2.01 ± 0.26,t=14.909), neck shoulder ache (0.87 ± 0.16 vs. 1.92 ± 0.69,t=10.266), numbness (0.95 ± 0.14)vs. 1.87 ± 0.16,t=29.844), the total integral (2.16 ± 0.75 vs.3.89 ± 1.14,t=8.756) integral were significantly lower than the control group(P<0.01).Treatment group RVA (40.03 ± 5.89 cm/svs. 34.26 ± 6.26 cm/s,t=4.628), the LVA (42.14 ± 5.42 cm/svs.33.89 ± 6.08 cm/s,t=6.985) rise and PI (0.79 ± 0.14 vs.1.04 ± 0.19,t=7.312) reduction were significantly better than those of the control group (P<0.01). The total effective rate in the treatment group was significantly better than the control group (91.7%(44/48)vs. 74.5%(35/47),χ2=3.863, P=3.863).Conclusion Touqing Capsule associated with Fengchi is effective for CSA. Its functional mechanism is correlated with improvement of haemodynamics of vertebral-basilar artery of the CSA patients.

OPG-RANKL-RANK signaling system is an important approach to regulate osteoclasts and osteoporosis / 中国组织工程研究

BACKGROUND:The OPG-RANKL-RANK transport system plays a crucial role in bone resorption mechanism of osteoclasts. OBJECTIVE:To observe the expression of OPG-RANKL-RANK signaling system in osteoclasts, osteoporosis, and the targeted therapy of OPG-RANKL-RANK signaling system. METHODS:We retrieved related literatures in the periodicals database with the key words of“osteoprotegerin, RANKL, RANK, osteoclasts, osteoporosis”in English and Chinese. According to the inclusion criteria, the literatures were included in this study after the evaluation of quality. RESULTS AND CONCLUSION:The mature of osteoclasts is mediated via OPG-RANKL-RANK signaling system and its associated signaling pathways. This signal pathway leads to the mechanism of osteoporosis. At the genetic and molecular levels, the targeted therapy of osteoporosis has become the focus. OPG-RANKL-RANK signaling system can provide a research platform for targeted treatment of osteoporosis, and OPG-RANKL-RANK signaling system is an important way to the regulation of osteoclasts and osteoporosis.

Image registration of a three-dimensional dynamic phantom in four-dimensional cone-beam computed tomography and four-dimensional computed tomography / 中华放射肿瘤学杂志

Objective To evaluate the image quality and registration accuracy of a three?dimensional ( 3D ) dynamic phantom in four?dimensional computed tomography ( 4DCT ) and four?dimensional cone?beam computed tomography ( 4DCBCT) . Methods The Computerized Imaging Reference Systems Dynamic Thorax Phantom Model 008A was scanned to get 4DCT and 4DCBCT images. Two balls with different diameters ( ?= 1 cm and ?= 2 cm) were used to simulate tumors with different sizes. The motion mode of the balls was 3D sinusoidal motion at 0?25 Hz ( the amplitudes along the x, y, and z axes were ±1?0 cm, ±0?4 cm, and ±0?2 cm, respectively). Gross target volumes (GTVs) from 10?phase bins, internal gross target volumes (IGTV), and target volumes on maximum intensity projection (MIP) and mean intensity projection (MeanIP) images were contoured and calculated. Target volumes on 4DCT or 4DCBCT images were compared with the static and dynamic volumes of the balls ( VS and VD ) . The matching index ( MI) of target volumes between the 4DCT and 4DCBCT images was analyzed after rigid image registration. Results The GTV in each phase of the image was larger than VS . The difference between the average GTV derived from 10 phases of 4DCT or 4DCBCT images and Vs of the small ball was larger than that of the large ball ( 35?03% vs. 22?66%;32?62% vs. 17?00%) . All the IGTVs and target volumes on MIP images were slightly larger than VD , but target volumes on MeanIP images were smaller than VD . The average MI of 10?phase bins of the small ball was smaller than that of the large ball ( 66?76% vs. 82?21%) . Moreover, MIs of IGTV,MIP, and MeanIP of the small ball were also smaller than those of the large ball ( 77?39% vs. 90?29%;75?90% vs. 89?28%;74?47% vs. 82?74%) . Conclusions In the case of a relatively small tumor volume and a relatively large motion amplitude, 4DCT and 4DCBCT should be used with caution for comparison of image registration.

Molecular mechanism of osteoclast, bone resorption and fracture healing by V-ATPase a3 transport system / 中国组织工程研究

BACKGROUND:The V-ATPase a3 transport system plays a crucial role on bone resorption mechanism of the osteoclasts. OBJECTIVE:To observe the expression of V-ATPase a3 transport system in fracture repair and the effect of V-ATPase a3 transport system inhibitor on fracture healing. METHODS:We retrieved related literatures in the periodicals database with the key words, and screen them according to the inclusion criteria. The literatures were included in this study after the evaluation of quality. RESULTS AND CONCLUSION:V-ATPase a3 transport system widely exists in the cytoplasm membrane and organel e membrane of eukaryotic cells. V-ATPase a3 has two structural domains:V0 and V1. V0 structural domain is the proton transport channel, V1 structural domain is mainly the hydrolysis of ATP. V-ATPase a3 transport system focuses on the fril ed edge of osteoclasts, H+is transported to form a high concentration, dissolves inorganic minerals and provides the acidic environment for hydrolytic enzymes, thus being involved in bone resorption. So V-ATPase a3 transport system is selected as the research target in the fracture repair and reshape.

Formulation of Exercise Prescription in Physiotherapy (review) / 中国康复理论与实践

@#The exercise prescription in the process of physiotherapy, including exercise intensity, exercise duration, frequency and type of movement, provide a consistent basis for rehabilitation to ensure the safety and efficacy of the treatment.

Risk Management in Physiotherapy for Some Chronic Diseases (review) / 中国康复理论与实践

@# With the popularization of rehabilitation and the development of the physiotherapy, some chronic diseases do not only mean the history of the patients, but also the objects of physiotherapy. The exercises will affect the cardiopulmonary function of the patient, and result in a high risk of accident. This article would review the risk factors and risk management in physiotherapy for chronic diseases.

Importance of Risk Management in Physiotherapy (review) / 中国康复理论与实践

@#Physiotherapy involves wide range elements. Many factors, such as the complications of the patients, may complicate the treatment. It is important for the physiotherapists to control the potential risk factors as much as to improve their efficacy.