1.Volumetric and dosimetric comparison in adaptive radiotherapy for patients with head and neck cancer:a systematic review and Meta-analysis
Biao ZHANG ; Pengfei JIA ; Lemin TANG
Chinese Journal of Radiation Oncology 2016;25(6):557-564
Objective To perform a systematic review and Meta-analysis on volumetric and dosimetric changes in target volumes and organs at risk (OARs) in adaptive radiotherapy (ART) for patients with head and neck cancer (HNC),and to investigate the role of ART in the treatment of HNC.Methods Literature retrieval was performed to include related studies,and the parameters of primary tumor,GTV-T and GTV-N,parotid volume,D95 and Dmean of target volumes,Dmean of ipsilateral and contralateral parotid volume (I-PG and C-PG),and Dmax of the spinal cord and brainstem.Results A total of 17 studies involving 336 patients were included in the meta-analysis.Primary tumor and parotid volume changed significantly.The volumes of GTV-T,GTV-N,and I-PG were significantly reduced during the 15-20th radiotherapy and after the 20th radiotherapy (P<0.05),and the C-PG was significantly reduced after the 20th radiotherapy (P=0.004).The analysis of actual dose showed that the D95 and Dmean of primary tumor showed no significant differences,and during the 15-20th radiotherapy,the Dmax of the spinal cord was increased by 2.26 Gy (P=0.000),while the Dmax of the brainstem showed no significant changes before the 20th radiotherapy and was increased by 1.78 Gy after the 25th radiotherapy (P=0.020).In addition,the Dmean of I-PG was increased by 2 Gy during the 20-25th radiotherapy (P =0.0001),and the D of C-PG was increased before the 20th radiotherapy and showed no significant changes after the 25thradiotherapy (P=0.110).The dosimetric analysis of ART showed that the Dmax of the spinal cord and brainstem was reduced significantly (spinal cord:MD =-2.15,95% CI-3.12 to-1.18,P=0.000;brainstem:MD =-2.20,95% CI-3.32 to-1.09,P=0.000).The Dmean of I-PG was reduced by about 3.5 Gy,and the sensitivity analysis revealed that the results of Dmean of C-PG were unstable.Conclusions The volumes of primary tumors and parotid glands change significantly,and the actual doses of OARs (Dmax of the spinal cord and brainstem and Dmean of the parotid glands) significantly increase,while the doses of GTV-T and GTV-N show no significant changes.ART can effectively protect the OARs,and patients with locally advanced HNC who receive concurrent chemoradiotherapy can obtain good dose gains from ART plan performed during the 15-20th radiotherapy and at about the 25th radiotherapy.
2.Effects of positioning robustness on dosimetry for intensity-modulated radiation therapy and volumetric modulated arc therapy
Biao ZHANG ; Pengfei JIA ; Lemin TANG
Chinese Journal of Radiation Oncology 2016;25(7):676-680
Objective To compare the effects of positioning robustness on dose distribution between intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) for head and neck tumor,and to evaluate their needs for image-based guidance.Methods Thirty patients with nasopharyngeal carcinoma undergoing IMRT were enrolled as subjects.The VMAT plans were designed according to the clinical dosimetric requirements and the dose calculation was made by the AAA method.For the two plans in each patient,the isocenters were shifted by ±1.0,±3.0,and ±5.0 mm along the original x,y,and z axes to simulate the impacts of positioning errors in left-right (LR),superior-inferior (SI),and anterior-posterior (AP) directions,respectively,on dose distribution.The dose-volume histogram parameters were analyzed in 60 references and 1080 re-calculated plans.Comparison was made by paired t-test.Results When the error was 1 mm,the average deviations of gross tumor volume (GTV) D98,clinical target volume (CTV) D95 and heterogeneity index,and planning gross tumor volume (PGTV) V95 were<0.5%.When the error was 3 mm,the average dose deviations of GTV and CTV were<1.0% and significantly larger in VMAT than in IMRT;the average dose deviation of PGTV was large (GTV D98,P=0.00;CTV D95,P=0.00);the average deviations of PGTVnxV95 and PGTVndV95 were significantly smaller in IMRT than in VMAT (1.64%vs.1.95%,P=0.01;1.73% vs.2.63%,P=0.00).The deviations of parameters became larger with the increasing positioning error and were significantly larger in VMAT than in IMRT (GTV D98,P=0.00;CTV D95,P=0.00;CTV HI;P=0.00;PGTV V95;P=0.01).Compared with the target volume,Dmax to the spinal cord and brain stem had larger deviations.However,there were no significant differences in Dmax to the spinal cord and brain stem between IMRT and VMAT.Conclusions The IMRT and VMAT plans are both robust when the positioning error is small (<3 mm).Compared with IMRT,VAMT is more sensitive to the positioning error,mainly in the target volume.The difference between the two plans becomes larger with the increasing positioning error.An increase in the frequency of image-based guidance is recommended for patients undergoing VMAT.
3.Clinical features and ageing-related changes in patients with venous thromboembolism
Lijun KANG ; Jianwen FEI ; Pengfei YU ; Yan TANG
Chinese Journal of Geriatrics 2010;29(1):46-48
Objective To investigate the clinical and epidemiological characteristics of pulmonary thromboembolism (PTE) and deep venous thrombosis (DVT). Methods The clinical data of 114 200 inpatients from June 2002 to June 2008, including gender, age, smoking history, primary disease and risk factors, were reviewed. Results There were 1445(1.27%) cases with venous thromboembolism (VTE), while 1433(1. 25%) patients suffered from DVT and 153(0. 13%) patients suffered from PTE, 16(11. 11 %) patients were dead of PTE. Of all the DVT patients, there were 1348(94. 1%) cases with DVT of lower limbs with no significant difference between left or right lower limb (P>0. 05). There were 49(3.4%) cases with inferior vena cava, 23(1.6%) cases with cavitas pelvis veins and 13(0. 9%) cases with upper extremity veins. The peak ages of morbidity were between 51 to 60 years. Conclusions The incidence of VTE is increasing with ageing and there is no significant difference between males and females. The most common risk factors for thromboembolism include trauma, surgery, cardiac and pulmonary disease, age over 50 years, deep phlebitis, long-term smoking, cancer, pregnancy, childbirth, braking, history of VTE, etc. We may lower the incidence and mortality of VTE by strengthening prevention work according to the high risk factors.
4.Dosimetric comparison between volumetric-modulated arc therapy and intensity-modulated radiotherapy for esophageal cancer:a meta-analysis
Han GAO ; Pengfei JIA ; Bingsen CHEN ; Lemin TANG
Chinese Journal of Radiation Oncology 2017;26(9):1055-1061
Objective To investigate the dosimetric comparison of target volumes and organs at risk (OAR) between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for esophageal cancer by a meta-analysis.Methods A literature search was performed to collect the clinical studies on dosimetric comparison between VMAT and IMRT.The primary endpoints of interest were dosimetric parameters of target volumes and OAR, number of monitor units (MUs), and treatment time (TT).Results A total of 17 studies involving 323 patients were included in this meta-analysis.When the total dose was>50.4 Gy, VMAT showed significantly lower mean dose (Dmean) of gross tumor volume (GTV) and maximum dose (Dmax) of planning target volume (PTV) than IMRT (P=0.009;P=0.039).There were no significant differences in Dmean, V30, and V40 of the heart, Dmax of the spinal cord, and V5, V10, and Dmean of the lung between VMAT and IMRT (P>0.05).VMAT showed significantly lower V15, V20, and V30 of the lung than IMRT (P=0.001;P=0.000;P=0.023).When the single dose was 1.8 Gy and 2.0 Gy, VMAT showed significantly lower TT (reduced by 323.5 s and 193.7 s) and number of MUs (reduced by 275.4 MU and 134.2 MU) than IMRT (P=0.000 and 0.009;P=0.000 and 0.022).Conclusions VMAT can significantly reduce TT, MUs, irradiation dose to the lung, and the risk of radiation pneumonitis, and improve the utilization rate of equipment.Compared with IMRT, VMAT has no significant advantages in protection of the spinal cord and the heart and dosimetric parameters of target volumes except Dmean of PTV and Dmean and Dmax of GTV when the total dose was ≤50.4 Gy.
5.Research on application of MRI in measuring acupuncture dangerous depth at Yamen and Fengfu
Juan TANG ; Xiaolong WANG ; Xingfu LIAO ; Pengfei OUYANG
Chongqing Medicine 2014;(11):1317-1319
Objective To determine the dangerous depths of acupuncture at Yamen(GV15) and Fengfu(GV16) in different age groups and different body types based on MRI measurements and to analyze their distribution chracteristic .Methods 98 patients of different age groups in the affiliated hospital of Hainan Medical College from June to December 2012 were selected and the each age group was divided into 3 types :asthenic type ,moderate type and endomorphy type according to the Rohrer index .All images took the median sagittal position .The dangerous depth was measured according to the clinical operation habit and actual feasibility .Re-sults The difference in the acupuncture depth of GV15 and GV16 among different asthenic type patients in different age groups had no statistical significance ;in the moderate type patients ,the difference in the acupuncture depth of GV15 and GV16 between the age group of 18- <45 years and 45-60 years had the statistical significance(P=0 .029 ,P=0 .018);in the endomorphy type pa-tients ,the difference in the acupuncture depth of GV15 and GV16 between the age group of 45-60 years and the other age groups had the statistical significance(P<0 .05) .Conclusion The dangerous depth of GV15 and GV16 had no correlation with age ,but is positively correlated with the Rohrer index ,i .e .,the dangerous depth of GV15 and GV16 is increased with the increase of Rohrer index .
6.Delayed treatment of 51 pediatric displaced femoral neck fractures
Pengfei ZHENG ; Li JU ; Jie CHEN ; Kai TANG ; Yue LOU
Chinese Journal of Orthopaedic Trauma 2016;18(5):375-380
Objective To compare open versus closed reduction in treatment of children with displaced femoral neck fracture whose reduction is delayed by more than 24 hours.Methods We retrospectively reviewed 51 children who had been treated at our department for femoral neck fracture between May 2005 and May 2012 after their reduction had been delayed for more than 24 hours.They were 37 boys and 14 girls,1.7 to 15.5 years of age (average,9.1 years).According to Delbet's classification,27 cases belonged to type Ⅱ,18 to type Ⅲ,and 6 to type Ⅳ.Of them,18 underwent closed reduction and 33 open reduction.Their complications were recorded in detail.Their therapeutic results were evaluated according to Ratliff's criteria and compared between the 2 methods of reduction.Results The 51 children were followed up for an average of 36.7 months (range,from 17 to 61 months).Anatomic reduction was achieved in 6 cases in the closed reduction group (33.3%) and 29 cases in the open reduction group (87.9%),respectively.All fractures healed after an average of 10.9 weeks (range,from 9 to 13 weeks),with one exception of nonunion in the closed reduction group.The incidence of femoral head necrosis in the closed reduction group (27.8%,5/18) was significantly higher than that in the open reduction group (15.2%,5/33) (P < 0.05).According to the Ratliff's evaluation at the final follow-ups,the good to excellent rate in the closed reduction group(66.7%,12/18) was significantly lower than that in the open reduction group (84.8%,28/33) (P <0.05).Coxa vara occurred in 3 children in the closed reduction group but in none in the open reduction group.Conclusion Open reduction with internal fixation may lead to better outcomes than closed reduction in the treatment of children with displaced femoral neck fracture whose reduction is delayed by more than 24 hours,probably because open reduction can result in better reduction quality.
7.Development of dynamic EMG scanning signal generator.
Yong TANG ; Pengfei BAI ; Zongtao LI
Chinese Journal of Medical Instrumentation 2008;32(6):446-448
Development of a dynamic EMG scanning signal general based on microcontroller is introduced to be used in such fields as research of dynamic magnetic resonance scanning and moving muscle surface EMG. Optical fiber and photoelectrical switch are applied to work in strong electromagnetic environments to produce trigger signal which is similar to ECG. The occurrence of signals and the activity of the scanned bodies can be delayed at will. The results show that it not only has complete functions, simple operation, but also has superior capability of stabilization and credibility than the same product.
Electromyography
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instrumentation
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methods
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Equipment Design
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methods
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Humans
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Signal Processing, Computer-Assisted
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instrumentation
8.Molecular characteristics of the hemagglutinin and neuraminidase of influenza B viruses isolated in Jiangsu province, 2011
Wei LI ; Pengfei LUO ; Fei DENG ; Yuanfang QIN ; Hairong ZI ; Fenyang TANG ; Xian QI ; Pingmin WEI
Chinese Journal of Microbiology and Immunology 2012;(12):1026-1033
Objective To characterize the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) of influenza B viruses isolated in Jiangsu province,2011.Methods Thirteen strains of influenza B virus in different areas and epidemic period in Jiangsu province,2011 were selected for whole-genome sequencing,and analysis of molecule epidemic characteristics for HA and NA was carried out by bioinformatics method.Results Of the 13 randomly selected influeuza B strains,10 strains were assorted to Victoria lineage strains with NA genes from Yamagata lineage,and 3 strains belong to Yamagata lineage.Compared nucleotide and amino acid sequences of HA and NA genes with their vaccine strains respectiuely,196/197 glycosylation site appeared on HA1 gene in Yamagata/Victoria isolates virus.Conclusion Both B/Victoria and B/Yamagata lineage viruses co-circulated in Jiangsu province,and reassortant virus of Victoria lineage were predominant virus.
9.Progress on chemical components and diuretic mechanisms of traditional Chinese diuretic medicines Poria cocos,Cortex Poriae, Polyporus umbellatus and Alisma orientalis
Yuhui ZHAO ; Dandan TANG ; Danqian CHEN ; Yaiong FENG ; Quanfu LI ; Pengfei LI ; Yingyong ZHAO
Chinese Journal of Pharmacology and Toxicology 2014;(4):594-599
Poria cocos,Cortex Poriae,Polyporusumbellatusand Alisma orientalisare common tra-ditionaI Chinese diuretic medicines. According to reported Iiterature,P.cocostriterpenes and poIysaccha-rides,steroids and tetracycIic triterpenes are the main chemicaI components of P.cocos,its epidermis, Pol.umbellatusand A.orientalis,respectiveIy. most of these diuretic drugs contain tetracycIic triterpenes and steroids,which have a simiIar structure to aIdosterone nucIeus structure. Therefore,this characteris-tic may reveaI their diuretic mechanisms. The tetracycIic triterpenes and steroids may exert diuretic effect through competitive inhibition of aIdosterone receptors in different parts of tubuIar reabsorption to increase urine output. The present articIe reviewed the chemicaI components of these diuretic Chinese medicines. Furthermore,their bioactive components and action mechanisms were aIso anaIyzed and discussed.
10.Detection of the immunologic rejection after xeno-islet transplantation:a study by MR imaging enhanced with superparamagnetic iron oxide marking CD4+T cell antibody
Wei NIE ; Yiya TANG ; Pengfei RONG ; Bin YE ; Zheng YE ; Qiongjuan TONG ; Wei WANG
Chinese Journal of Radiology 2008;42(10):1084-1088
Objective To evaluate the feasibility of the diagnosis of the early immunologic rejection after xeno-islet transplantation by MR imaging enhanced with superparamagnetic iron oxide(SPIO)marking CD4+T cell antibody.Methods Two thousand neonatal porcine islets(NPI)were transplanted under the left renal capsule of BALB/C nude mice.When the grafts could be observed bv MRI.107 human PBMC was intraperitoneal injected to nude mouse models to reconstitute the human immunologic system,20 mice were reconstituted.Before and 3,7,14 days after reconstitution of human immunologic system on BALB/C nude mice,MRI imaging Was performed half an hour after intravenous injection of nano-immunomagnetic beads via vena caudalis to observe the grafts'MRI signal.BALB/C nude mice were sacrificed after MRI scanning immediately,the histopathologic examination was assessed on grafts,the results were compared with MRI results.And calculate the sensitivity,specificity,Youden index number and coincidence of the MRI for immunologic rejection.Results Grafts can be observed bv MRI 3 weeks after islet cell transplantation (before immunologic rejection modeling),there is no abnormal MRI signal detected in nude mice'graft region after mierobeads injected.Seven days after building of immunologic rejection model,MRI hypo-signal in graft site is shown in the T2 WI sequence after nano-bioprober injected.Histopathologic assessments were employed on grafts in nude mice immediately(HE and immunohistochemistry staining),the results shown that there are a lot of T lymphocyts infiltrated in graft region.implying the occurrence of immunologic rejection.And the sensitivity,specificity,Youden index number and coincidence is:(72.96±0.24)%,100%,0.73±0.24,(88.46±0.13)%respectively.The correct Kappa between the MRI and the imunohistochemistry staining was 0.76.Conclusion The cellular immunological rejection to xeno-islet grarts can be assessed with nano-bioprobe with anti-CD4+ antibody MR imaging,real time,and noninvasively.