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Objective To evaluate the inter-fraction setup error during the treatment with megavoltage computed tomography (MVCT) and provide theoretical basis for clinical target volume-planning target volume (CTV-PTV) margins for nasopharyngeal carcinoma (NPC) patients treated with tomotherapy.Methods Thirty-seven consecutive NPC patients treated with tomotherapy were prospectively enrolled for the study between February 2015 and September 2015.For each patient,one MVCT scan was obtained after conventional positioning,online correction and tomotherapy delivery daily,and the scan was registered to the planning CT to determine inter-fraction setup error.The expanding margin for PTV (MPTV) was calculated with the recipe:MPTV =2.5∑ + 0.76 (∑:systematic error;6:random error).Results The average absolute errors of the inter-fraction were (2.102 ± 0.040 6) mm,(1.490 ± 0.034 8) mm,(1.306 ± 0.335) mm and (1.392 ± 0.038 4) ° in the three dimensions.Gradual increases in both inter-fraction three-dimensional displacement were observed with time and treatment (P ＜ 0.05).The total MPTV ac counting for inter-error were 3.467 5 mm,2.979 5 mm and 2.888 5 mm.Conclusions Tomotherapy irradiation technology personalized MPTV should be adopted for the design of tomotherapy plan.Displacement increased as a function of time.
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Objective To explore the inter-fraction setup errors and affecting factors from data of daily fan-beam megavoltage computed tomography(MVCT). Methods A total of 37consecutive NPC patients treated with tomotherapy were hospitalized during the period of February 2015 to September 2015. For each patient,one MVCT scan was obtained after conventional positioning ,online correction and tomotherapy delivery daily ,and the scans were put into the planning computed tomography to determine inter-fraction setup errors. The MPTV was calculated with the equation:MPTV=2.5∑+0.7σ(∑:systematic error;σ:random error). Results The average absolute errors of the inter-fraction were(2.102 ± 0.0406)mm,(1.490 ± 0.0348)mm,(1.306 ± 0.335)mm and(1.392 ± 0.0384)° at three dimensions. The total MPTV accounting for inter-error was 3.4675 mm,2.9795 mm,and 2.8885 mm. Gradual increases in both inter-fraction three-dimensional displacement were observed with time and treatment(P < 0.05). Univariate analysis revealed that weight loss and retraction of neck lymph nodes were affecting factors of set-up errors. Conclusions 3 mm margins uniformly expended from clinical target volume to planning target volume may not be suitable. The personalized margin should be adopted for the design of IMRT planning. Displacement increases as a treatment course is prolonged.
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Objective To assess the variation in patient setup corrections for three different anatomic treat-ment sites using daily pretreatment megavoltage CT(MVCT)in helical tomotherapy,and to analyze alternative refer-ence margins for specific tumor site.Methods Sixty patients treated for three anatomical sites on helical tomotherapy were analyzed.Daily MVCT was carried out for registration and setup corrections before each treatment fraction.Setup errors and rotational setup corrections from 587 head and neck,500 thoracic,371 abdomen and gynecology MCVT imaging were input to statistical analysis.Incidences of three dimensional vector error lengths were calculated for each anatomic site.Overall distribution histograms of the three -dimensionally error was presented using GraphPad Prism 5.The distributions of systematic and random setup errors were quantitative analyzed and the additional margins required were also taken into account.Results 1 458 MVCT scans were implemented for sixty patients.Head and neck had lower frequencies of translational setup errors than others.Frequency of at least 3mm three -dimensional setup errors for head and neck,thoracic,abdomen and gynecology was 55.3%,70.8%,79.8%,respectively.This fre-quency decreased to 17.5%,40.6%,47.2% if 3D vector distance ≥5mm was scored.Overall systematic errors ranged from -1.4mm to 2.7mm,abdomen and gynecology had the largest setup errors in the vertical direction which was statistically significant(χ2 =19.3,P <0.05).The suggested margins should be increased by 4 -7 mm in three -dimensional direction for head and neck,9 -14mm for thoracic,10 -17mm for abdomen and gynecology.Conclusion Differences in setup corrections are perceived between head and neck,thoracic,abdomen and gynecology.The accura-cy of patient positioning can be improved if pre -treatment daily MVCT scans are put into use.Results from setup cor-rection can provide evidence for tumor treatment margin and improve the accuracy of regular radiotherapy.
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Objective To investigate microRNA(miRNA)expression profiles in peripheral blood and skin lesions of patients with psoriasis vulgaris(PV), and to seek miRNAs consistently expressed in peripheral blood and skin lesions. Methods A miRNA microarray was used to screen differentially expressed miRNAs in skin lesions and peripheral blood samples between 17 patients with PV and 4 healthy human controls, and real?time fluorescence?based quantitative PCR(RT?qPCR)to verify the differentially expressed miRNAs. The correlations of these differentially expressed miRNAs with psoriasis area and severity index(PASI)score were assessed by Pearson correlation analysis. Results The Agilent human miRNA microarray profiling revealed 15 miRNAs consistently expressed in skin lesions and peripheral blood of patients with PV. Of the 15 miRNAs, 7 were verified as consistently expressed miRNAs by RT?qPCR. Among the 7 miRNAs, the expression intensity of miR?30e?5p, miR?192?5p, miR?17?3p and miR?1227?5p was negatively correlated with PASI scores(all P0.05). Conclusion Some miRNAs are consistently expressed in skin lesions and plasma of PV patients, which are expected to serve as biomarkers for evaluation of psoriasis severity.
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OBJECTIVE:To virtually screen lignanoid compounds with inhibitory effect of histone deacetylase(HDAC)by vir-tual screening method. METHODS:Using“lignanoid”as keyword,requiring CNKI,VIP,PubMed and other database,lignanoid compounds were collected as ligand to establish ligand base, histone deacetylase receptor HDAC2 (PDB code:4LXZ) and HDAC8 (PDB code:1T69) were selected from PDB database,and then ligands and 3D active site of receptors were docked by SYBYL-X 2.0 software. The affinity of receptors to ligand was reflected by total score. RESULTS:345 lignanoid compounds, 4LXZ and 1T69 primary ligand were used to establish ligand base which included 347 ligands. Ligands No.275,271,110,200, 056,258,181,129,037,270,187 were demonstrated good affinity with receptors HDAC2 and HDAC8. Ligands and receptors residue were docked via hydrogen bond. CONCLUSIONS:Lignanoid compounds have inhibitory effect on HDAC;virtual screen-ing method is effective in natural product activity prediction,which can provide quick access to and theoretical guidance for new pharmacological studies of lignanoid compounds.
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Cancer and stroke are the major diseases causing serious harm to human health.Studies show that as compared with normal people,patients with cancer are more prone to stroke.We reviewed the research progress on cancer patients with stroke within the past decade,including the common cancer type which causes stroke,the stroke pathogenesis of cancer patients,clinical characteristics,treatment and prognosis of cancer patients with comorbid stroke,in order to provide the evidence for the prevention and treatment of stroke in cancer patients.
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As one important part of external conditions,a harmonious social environment is necessary precondition for human health.This article inquires the function of a harmonious social environment to human health from internal demand,basic prerequisite and post-disaster social environmental support of human health.