射波刀Xsight患者六维方向数据分析

目的:分析30例Xsight追踪方式的患者治疗过程中所有曝光点生成的六维方向数据。方法:随机选择30例Xsight追踪方式的患者,在真空垫固定、CT-SIM定位,使用G3射波刀进行治疗,共采集1 358个曝光点图像,得到1 358组需要机械臂校准六维方向数据,其中包括患者移动超出射波刀机械臂校准范围的337个曝光点的数据,进行各个方向的平均值、标准差的比较。结果:在患者6个方向上的左右平移LET(+)/RIG(-)、前后平移ANT(+)/POS(-)、头脚平移NIF(+)/SUP(-)、左右旋转R(+)/L(-)、头高低Head-up(+)/Head-up(-)、逆顺时针CCW(+)/CW(-)上的最大值为2.3 mm、2.0 mm、1.7 mm、2.5°、1.6°、2.1°,最小值为-2.8 mm、-2.1 mm、-1.2 mm、-2.1°、-1.3°、-1.5°,中位值为-0.4 mm、0.3 mm、0.1 mm、0.6°、0.2°、0.4°,变化范围为5.1 mm、4.1 mm、2.9 mm、4.6°、2.9°、3.6°。结论:在射波刀立体定向精确放疗中,患者本身的运动呈现出对称运动,幅度相当,中位值接近于0,但是患者本身的运动变化范围超出了射波刀Xsight系统所要求的总误差不超过0.95 mm的要求,尤其是左右平移LET(+)/RIG(-)及左右旋转R(+)/L(-)(°),这充分说明了射波刀系统在出射束前进行机械臂校准的必要性和重要性。     

固定束质子治疗病人摆位系统的精确性评估:等中心旋转运动

目的 评估固定束质子治疗的病人摆位系统等中心旋转运动的精确性。方法 将2 mm直径金属小球固定于床面之上并校准到房间等中心(ISO)。依次选择11个角度分别对治疗床进行等中心旋转,到达设定位置后使用数字影像摆位系统(DIPS)分别测算出小球与房间等中心的位移偏差。在不同时间共重复进行了四次测量,统计分析四组测量结果。结果 所有数据中,治疗床在-110°时发生位移最大,X、Y、Z轴方向分别是(0.29±0.05)mm、(0.21±0.04)mm和(-0.21±0.04)mm,小球与ISO总位移偏差(0.41±0.07)mm(1SD)。治疗床在30°时发生位移最小(0°除外),X、Y、Z轴方向分别是(-0.03±0.05)mm、(0.05 ±0.05)mm和(0.00±0.00)mm,小球与ISO总位移偏差(0.05±0.06)mm。结论 等中心旋转是实现固定束质子等中心多角度照射的关键运动模式。它是一种复杂的组合运动,包括治疗床床面的角度旋转运动和治疗床底座的水平轴向运动。由于质子治疗对靶灶精确定位的严格要求,这种组合运动的精度在质子治疗摆位中就显得格外重要。测量结果数据均小于0.5 mm。完全满足质子治疗PPS摆位精度的要求。     

摆位误差对患者剂量学的影响

目的 :研究摆位误差对直肠癌调强放射治疗计划剂量学的影响。方法 :对1例直肠癌术后患者设计多野静态调强放射治疗计划。计划确认执行后,共设计9个新计划:将等中心点仅向患者头、脚、背、腹、左、右方向分别平移5mm;将等中心点同时向患者头、背、左移动5 mm;将等中心点同时向患者脚、腹、右移动5 mm;按开始放疗前5次锥形束CT(cone beam CT,CBCT)扫描配准情况,选择最大误差移动等中心。模拟以上不同的等中心摆位误差,并将其与原计划进行比较,观察靶区及主要危及器官股骨头、膀胱、小肠的剂量变化。结果:以等中心同时向3个方向移动5 mm计划的计划靶区(planning target volume,PTV)和正常器官剂量影响最大;各个计划对临床靶区(clinical target volume,CTV)剂量影响不大;各个计划正常器官的高剂量D2(2%靶区体积所受照射剂量)和平均剂量对小肠、膀胱影响不大,但对股骨头影响很大。结论:摆位误差对靶区PTV剂量有较大的影响,尤其是靶区低剂量D_(98)(98%靶区体积所受照射剂量)明显降低,可能影响治疗效果。对一些摆位误差较大的患者,应增加CBCT扫描次数并予以在线实时修正,以保证放射治疗计划的精准实施。     

应用OBI系统分析鼻咽癌调强放疗的摆位误差

目的:应用机载影像系统(OBI)分析鼻咽癌调强放射治疗的摆位误差。方法:应用Varian-21EX医用直线加速器治疗38例鼻咽癌患者。在首次调强放射治疗前应用OBl系统获取锥形束断层扫描(CBCT)图像,前3 d每天1次,以后每周1次,将CBCT图像和计划CT图像匹配得出两者间平移和旋转误差。结果:首次扫描获得的平均误差分别为左右(-0.49±1.90)mm,头脚(0.64±1.36)mm,前后(-0.57±1.78)mm;旋转误差为(0.05±0.11)°。经首次校正后其余各次摆位误差减小为左右(0.30±1.01)mm,头脚(0.12±0.92)mm,前后(0.47±1.05)mm;旋转误差(-0.02±0.03)°。结论:应用OBI系统验证摆位误差可以提高摆位精度,减少周围正常组织的照射。对于鼻咽癌调强放疗,临床靶体积(CTV)到计划靶体积(PTV)的外放边界约为2 mm。     

基于电子射野影像系统推导头颈部肿瘤调强放疗计划靶体积边界

目的随着精准放疗的广泛临床应用,影响靶区照射精度的计划靶体积边界已成为放疗计划制定必须考虑重要因素之一。本研究通过电子射野影像系统测量头颈部肿瘤调强放疗的摆位偏差大小,在求证偏差值分布规律和方差齐性的基础上,试图推导出治疗计划中临床靶区(clinic target volume,CTV)外扩生成计划靶区(planning target volume,PTV)所需边界的宽度(marginptv,M_(ptv)),为后续临床计划设计提供依据。方法选取2018-05-20-2018-12-20福建医科大学附属第二医院和泉州市光前医院放疗科治疗的15例头颈部肿瘤患者为研究对象,在连续6周的治疗周期中,利用加速器机载电子射野影像系统共获取300帧野验证片,每例患者得到正交0°、90°或270°图像各10张,经与治疗计划生成的DRR片进行骨性配准,获取摆位偏差值。并检验偏差值分布规律。采用ICRU Report No.62方法计算CTV到PTV的边界。人群总体系统误差(∑)和人群总体随机误差(σ)分别有由个人系统误差的标准差和个人随机误差的标准差表示。结果经单样本Kolmogorov-Smirnov/Levene检验,对于1～6周的所有X(左右方向)、Y(头脚方向)、Z(腹背方向)轴方向上的偏差值的Z1～Z6/P1～P6分别为(0.448～0.758/0.614～0.988)、(0.511～1.038/0.23～0.953)、(0.508～0.922/0.363～0.959),均P>0.05,可认为偏差值分布均服从正态分布;单因素Levene方差分析结果显示,X、Y、Z轴方向上偏差值的P值分别为0.606(F=0.726)、0.498(F=0.881)和0.765(F=0.513),认为方差齐性;偏差值的离散趋势以算术均数表示,为样本实际测量值的平均数,X、Y、Z轴的摆位偏差均值及标准差分别为(-0.051±0.964)、(0.336±1.102)和(0.173±1.044)mm。应用ICRU Report No.62.法计算M_(ptv)结果 X=2.993mm,Y=3.223mm,Z=3.177mm,故可在三维方向上,取4mm作为CTV到PTV的扩展边界。结论该组资料属于连续性数值变量资料,认为资料服从正态分布,且具有方差齐性。本研究采用的体位固定方式,在头颈部肿瘤的调强放疗摆位中,固定性和重复性良好;采用ICRU Report No.62建议的方法,估算CTV到PTV外扩边界大小为4mm,可以充分保证95%患者群体的CTV获得95%的处方剂量覆盖。     

呼吸运动对TOMO放射治疗靶区剂量分布的影响

目的 了解呼吸运动对TOMO靶区剂量分布造成的影响。方法 使用运动模体模拟人体呼吸运动。使用SNC Patient分析软件将研究组胶片与对照组胶片进行比较,通过“通过率”指标评价呼吸运动对TOMO靶区剂量分布造成的影响。 结果 肉眼即可观察到有、无呼吸运动时胶片灰度在头-脚方向（即运动方向）上的分布存在不同;胶片分析得到的无呼吸运动时靶区包绕曲线宽度与治疗计划值最大偏差约2.4 mm,有呼吸运动时靶区包绕曲线宽度与治疗计划值最大偏差约27.2 mm;无呼吸运动时靶区半影宽度为31 mm（头方向）、28.5 mm（脚方向）,有呼吸运动时靶区半影宽度为39.7 mm（头方向）、37 mm（脚方向）;靶区剂量分布“通过率”仅为12.3%。结论 呼吸运动在运动方向上对TOMO靶区剂量分布造成的影响较大,临床制定治疗计划时呼吸运动对TOMO靶区剂量分布的影响不容忽视。     

床转角对宫颈癌非共面调强放疗计划的影响

目的：探讨床转角对宫颈癌非共面调强放疗(intensity-modulated radiation therapy,IMRT)计划靶区和危及器官剂量的影响。方法：回顾性选取在某院肿瘤科治疗的 20 例宫颈癌术后患者的病例资料,基于 Eclipse v13.6 计划系统,为每位患者制订一个 7 野共面 IMRT 计划(床转角为 0°),再改变部分射野角度下的床转角为 315°～355°和 5°～45°,每隔 10°设计一个非共面 IMRT 计划(共 10 个)。比较 2 种 IMRT 计划的靶区剂量学参数和膀胱、直肠、小肠、左右股骨头和骨盆等危及器官的剂量学参数。采用 SPSS 22.0 软件进行统计学分析。结果：非共面 IMRT 计划与共面IMRT 计划的靶区剂量学参数均无显著差异(P>0.05)。非共面 IMRT 计划的膀胱 V₃₀、V₄₀,直肠 V₃₀、V₄₀与共面 IMRT计划相比无统计学差异(P>0.05),除床转角为 345°外,其他床转角的非共面 IMRT 计划的小肠 D     

不同配准方式对鼻咽癌螺旋断层调强放射治疗患者摆位误差的影响

目的探讨在高能X射线计算机体层摄影(MVCT)引导下螺旋断层调强放射治疗中两种自动图像配准技术对鼻咽癌放射治疗患者摆位误差的影响。方法随机选取2016年10月至2017年10月采用螺旋断层调强放射治疗技术进行调强放射治疗的鼻咽癌患者22例,每例患者治疗前均行MVCT扫描,将扫描获取的MVCT图像与定位图像行骨配准、骨与软组织配准,分别记录患者左右(X轴)、头脚(Y轴)、腹背(Z轴)方向的线性误差以及绕此3个方向形成的旋转误差(U、V、W)这6个方面的配准数据,分析两种配准方式之间的差异。结果 22例患者共150组MVCT扫描图像数据,所选数据符合正态分布。其中骨配准在X轴、Y轴、Z轴方向的平移误差与绕此3方向的旋转误差分别为(0.946±1.701)mm、(0.937±1.059)mm、(0.077±1.161)mm与(-0.127±1.201)°、(-0.217±1.104)°、(-0.280±0.897)°;骨与软组织配准在X轴、Y轴、Z轴方向的平移误差与绕此3方向的旋转误差分别为(0.920±1.397)mm、(1.045±1.167)mm、(0.386±1.212)mm与(-0.156±1.079)°、(-0.142±0.648)°、(-0.169±0.685)°。将6个方向的摆位误差计量数据进行配对t检验,骨配准、骨与软组织配准两种配准方式在Y轴、Z轴方向上的平移误差比较,差异有统计学意义(P<0.05);其他4个方向的摆位误差比较,差异均无统计学意义(P>0.05)。结论鼻咽癌患者进行螺旋断层调强放射治疗时,为降低患者摆位误差,建议首选骨配准,必要时辅以手动微调直至满意为止。     

两种千伏级立体平面图像引导放射治疗系统临床一致性研究

目的:对比研究千伏(kV)级iScout图像引导放射治疗定位系统和射波刀Xsight脊柱追踪系统基于骨骼二维-三维(2D-3D)图像配准算法的临床一致性。方法:选取医院收治的30例行第四代射波刀Xsight脊柱追踪系统治疗的患者临床数据资料,采用配置i Scout系统成像几何参数,生成数字重组透视图像作为配准参考图像,加载Xsight系统影像板投影图像,应用i Scout系统骨骼定位方法实现2D-3D图像配准,计算患者病灶位置偏移。参照Xsight系统定位配准数据,选取3个平移头脚(S/I)、左右(L/R)和前后(A/P),以及3个转角绕头脚(Roll)、绕左右(Pitch)和绕前后(Yaw)3个方向共6个自由度作为评价参数,记录并对比两个系统的配准结果。结果:获取30例患者数据资料生成的分别由A、B投影图像构成564组投影图像,分析记录Xsight系统和iScout系统配准结果的差值,S/I、L/R和A/P的3个平移结果的差值分别为(0.100.24)mm、(-0.060.32)mm和(0.110.21)mm;Roll、Pitch和Yaw的3个转角结果的差值分别为(-0.010.35)、(0.070.23)和(0.010.24)。散点分布图显示两个系统6个自由度定位配准结果差值集中分布在0.5之间。结论:iScout系统与Xsight系统均基于kV级X射线2D-3D图像配准立体定位引导技术,临床比对结果一致性好。     

放化疗治疗脑胶质母细胞瘤术后残留临床观察

目的 研究同步加量调强放疗(SIB-IMRT)联合替莫唑胺化疗治疗脑胶质母细胞瘤术后残留的临床效果。方法 对56例脑胶质母细胞瘤术后残留患者行SIB-IMRT,靶区勾画:残留病灶勾画为GTV,外放5 mm为临床靶区(CTV),CTV外放5 mm为计划靶区(PTV);瘤床勾画为临床靶区(CTV1),CTV1分别外放15 mm和30 mm为计划靶区1(PTV1)和计划靶区2(PTV2),PTV、PTV1、PTV2处方量分别为2.5 Gy/次、2.3 Gy/次、2.0 Gy/次,5次/周,共25次;放疗期间每日口服替莫唑胺75 mg/m²。同步放化疗结束后,继续给予替莫唑胺150 mg/m²,连续口服5 d,28 d为1个周期,辅助化疗共6个周期。56例患者单纯行同步放化疗者26例为A组,放化疗结束后继续化疗6个周期者30例为B组。结果 全组56例患者中CR 7例(12.5%),PR 38例(67.8%),SD 8例(14.3%),PD 3例(5.4%);全组患者的有效率80.3%。全组平均生存时间为(29.82±9.11)月;1年、2年、3年生存率分别为96.4%、73.2%、33.9%;A组与B组比较平均生存时间、生存曲线差异均有统计学意义(P < 0.001)。放化疗的不良反应较轻,毒性反应以血液学毒性为主。结论 同步加量调强放疗联合替莫唑胺化疗加后续单药辅助化疗治疗脑胶质母细胞瘤术后残留患者有较好的临床效果,不良反应可耐受,建议临床推广应用。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.