Background: Cherenkov luminescence imaging has shown potential for relative dose distribution and field verification in radiation therapy. However, to date, limited research utilizing Cherenkov luminescence for absolute dose calibration has been conducted owing to uncertainties arising from camera positioning and tissue surface optical properties.Purpose: This paper introduces a novel approach to multispectral Cherenkov luminescence imaging combined with Fricke-xylenol orange gel (FXG) film, termed MCIFF, which can enable online full-field absolute dose measurement. By integrating these two approaches, MCIFF allows for calibration of the ratio between two spectral intensities with absorbed dose, thereby enabling absolute dose measurement.Methods: All experiments are conducted on a Varian Clinac 23EX, utilizing an electron multiplying charge-coupled device (EMCCD) camera and a two-way image splitter for simultaneous capture of two-spectral Cherenkov imaging. In the first part of this study, the absorbance curves of the prepared FXG film, which receives different doses, are measured using a fluorescence spectrophotometer to verify the correlation between absorbance and dose. In the second part, the FXG film is positioned directly under the radiation beam to corroborate the dose measurement capacity of MCIFF across various beams. In the third part, the feasibility of MCIFF is tested in actual radiotherapy settings via a humanoid model, demonstrating its versatility with various radiotherapy materials.Results: The results of this study indicate that the logarithmic ratios of spectral intensities at wavelengths of 550 +/- 50 and 700 +/- 100 nm accurately reflect variations in radiation dose (R2 > 0.96) across different radiation beams, particle energies, and dose rates. The slopes of the fitting lines remain consistent under varying beam conditions, with discrepancies of less than 8%. The optical profiles obtained using the MCIFF exhibit a satisfactory level of agreement with the measured results derived from the treatment planning system (TPS) and EBT3 films. Specifically, for photon beams, the lateral distances between the 80% and 20% isodose lines, referred to as the penumbra (P80-20) values, obtained through TPS, EBT3 films, and MCIFF, are determined as 0.537, 0.664, and 0.848 cm, respectively. Similarly, for electron beams, the P80-20 values obtained through TPS, EBT3 films, and MCIFF are found to be 0.432, 0.561, and 0.634 cm, respectively. Furthermore, imaging of the anthropomorphic phantom demonstrates the practical application of MCIFF in real radiotherapy environments.Conclusion: By combining an FXG film with Cherenkov luminescence imaging, MCIFF can calibrate Cherenkov luminescence to absorbed dose, filling the gap in online 2D absolute dose measurement methods in clinical practice, and providing a new direction for the clinical application of optical imaging to radiation therapy.

目的 探讨直肠癌术后调强放疗中治疗体位(仰卧位与俯卧位)、准直器调强方式[动态调强(SW)与静态调强(MSS)]、剂量计算算法[各向异性解析算法(AAA算法)与笔形束卷积算法(PBC算法)]、高能X射线能量(6 MV与15 MV)、放射野个数(7野与9野)以及计算网格尺寸(0.25 cm与0.50 cm)等多变量组合最佳治疗模式的剂量学特征.方法 采用控制单一变量法,分别比较6种条件(共计12个变量)对靶区和危及器官的剂量学差异.基于剂量学差异结果,比较6种条件中相对更优的6个变量串联而成的A组与相对较差的6个变量串联而成的B组对靶区和危及器官的剂量学影响.剂量学评价指标包括靶区和危及器官的剂量受量、靶区剂量适形度指数(CI)和靶区均匀性指数(HI)、机器跳数(MU)、出束时间.结果 对于多变量串联的统计学分析显示,采用俯卧位、AAA剂量算法、动态SW的多叶光栅(MLC)运动方式、15 MV的X线、0.25 cm计算网格尺寸且9野均分的6个变量串联的A组相较于采用仰卧位、PBC剂量算法、静态MSS的MLC运动方式、6 MV的X线、0.50 cm计算网格尺寸且7野均分的6个变量串联的B组,计划靶区(PTV)的平均剂量(Dmean)平均降低了1.2％,CI平均增加了 10.0％,HI平均降低了 30.3％;小肠最大剂量(Dmax)平均降低了 3.0％,膀胱4 000 cm3体积对应的剂量(V40)平均降低了 31.2％,股骨头Dmax平均降低了 3.6％.结论 直肠癌术后调强放疗采用俯卧位、AAA剂量算法、动态SW的MLC运动方式、15 MV的X线能量、0.25 cm计算网格尺寸和9野均分野这6个变量组成的治疗模式,是经临床剂量学证实的对直肠癌术后调强放疗的更优治疗模式.

目的:研究ExacTrac X射线图像引导系统(ETX)在盆腔肿瘤的立体定向体部放射治疗(SBRT)中的摆位误差纠正精度.方法:选择24例盆腔肿瘤SBRT患者,在SBRT治疗前,先用ETX获取六维治疗床校正前的误差和校正后的残余误差,再利用锥形束CT(CBCT)获取验证误差,并对获取的上述三组误差值进行数据分析.结果:六维治疗床校正前各方向上的误差值相对较大,其中Xt范围为-7.88～7.37 mm,Yt范围为-7.7～8.37 mm,Zt范围为-7.43～7.82 mm,Xr范围为-2.78°～2.43°,Yr范围为-2.38°～2.21°,Zr范围为-2.51°～2.46°;ETX校正后的残余误差比校正前的预摆位误差明显减少(P<0.05),其中校正后各方向平移误差均小于2 mm,旋转方向误差均小于1°;ETX与CBCT所获平移验证误差值相减的差值很小,且差值占比绝大多数(>94％)落在了0～1 mm误差的区间上.结论:对于盆腔肿瘤SBRT,ETX的误差纠正能力媲美CBCT,可以代替CBCT,满足高精度的治疗要求.

目的 利用ExacTrac X射线图像引导系统(ExacTrac X-ray,ETX),对中上腹部肿瘤的立体定向放射治疗(ster-eotactic radiation therapy,SRT)中的摆位误差进行分析研究,探讨ETX在中上腹部肿瘤中临床应用价值及注意事项.方法 选择24例接受SBRT治疗的中上腹部肿瘤患者,并将其分A、B两组,其中A组为肝癌、肾癌及胰腺癌患者,B组为椎骨转移瘤患者.首先用ETX获取六维治疗床校正前的预摆位误差和校正后的残余误差,再利用锥形束CT(cone beam CT,CBCT)进行二次验证并获取验证误差,并对获取的上述三组误差值进行数据分析.结果 (1)ETX校正后残余误差比ETX校正前预摆位误差明显减少(P＜0.05);(2)ETX校正后,A组患者误差值大于B组患者;(3)CBCT验证平移误差中,A组患者明显大于B组患者;(4)A组患者的CBCT验证误差与ETX校正后残余误差之间差值较大,而B组患者的CBCT验证误差与ETX校正后残余误差之间差值较小.结论 对于中上腹部肿瘤SBRT而言,与骨性结构位置密切的椎骨转移瘤,ETX误差精确度媲美CBCT,完全可以代替CBCT进行误差纠正.而对于肝癌、肾癌及胰腺癌等与骨性结构距离较远的肿瘤,ETX误差纠正精度不如 CBCT.

目的 探讨ExacTrac X线(ETX)图像引导系统在非小细胞肺癌(NSCLC)立体定向体部放射治疗(SBRT)中的应用价值.方法 选择2020年5—10月于医院接受SBRT的NSCLC患者24例,治疗前均采用ETX图像引导系统获取六维治疗床校正前、后的误差,并利用锥形束CT(CBCT)获取验证误差,比较上述3组误差.结果 六维治疗床校正前各方向上的误差相对较大,其中Xt范围为-4.61～6.78 mm,Yt范围为-8.53～5.46 mm,Zt范围为-6.23～5.12 mm,Xr范围为-2.26°～1.95°,Yr范围为-2.42°～2.23°,Zr范围为-2.41°～2.64°;校正后各方向平移误差均<1 mm,旋转误差均<0.5°,其中Yt、Zt、Xr和Zr与校正前比较,差异有统计学意义(P<0.05);ETX图像引导系统与CBCT所获的平移误差的差值很小,且>92％的差值位于0～2 mm区间内.结论 对于行SBRT的NSCLC患者,ETX图像引导系统和CBCT在摆位误差纠正能力方面的可靠性和精确度较一致,且ETX还具有耗时短、剂量低和可实时监控的优势.

目的:探讨ExacTracX射线图像引导系统在食管癌调强放疗全程验证中应用可行性.方法:收集2019年2月～2020年9月在本院接受调强放疗的20例食管癌患者为观察对象,采用ExacTracX射线图像引导系统全程实施图像引导放疗,分析3个平移方向误差及相对应的3个旋转方向上的误差.结果:采用Wilcoxon检验分析比较校正前后的摆位误差,20例食管癌患者获得校正前后各600组6D误差值.校正前后左右、腹背、头脚方向的平移误差分别为(1.978±1.945)m m、(0.289±0.344)m m、(2.515±2.449)m m和(0.332±0.453)m m、(2.892±2.782)m m、(0.381±0.463)m m.左右、腹背、头脚方向旋转摆位误差分别为(0.736±1.053)?、(0.149±0.308)?、(0.794±1.062)?和(0.221±0.366)?、(0.691±1.136)?和(0.241±0.393)?,各方向校正前后摆位误差的差异均有统计学意义.结论:ExacTracX射线图像引导系统能够有效校正摆位误差,可以明显地提高调强放疗的精度.

目的:探讨ExacTrac X射线(ETX)图像引导系统在颅内肿瘤的无创立体定向放射治疗(FSRT)中的临床应用价值.方法:选择在医院就诊的30例胶质瘤患者及肺癌脑转移患者,在FSRT治疗前,采用ETX图像引导系统获取六维治疗床校正前的预摆位误差、校正后的残余误差以及利用锥形束CT(CBCT)获取的验证误差,共计3组误差,采用配对t检验、差值占比分析等方法对X方向(左右)的平移误差(Xt)、Y方向(头脚)的平移误差(Yt)、Z方向(前后)的平移误差(Zt)及围绕X、Y及Z方向的旋转角度Xr、Yr和Zr方向的误差进行数据分析.结果:ExacTrac X图像引导系统校正前各方向上的误差值相对较大,其中Xt范围为-4.63～5.11 mm,Yt范围为-6.68～5.43 mm,Zt范围为-5.03～4.88 mm,Xr范围为-2.14°～1.91°,Yr范围为-2.34°～2.25°,Zr范围为-2.36°～2.78°;校正后各方向上的误差值明显减小,校正后平移误差≤0.5 mm,旋转方向误差均<0.5°,其中Xt范围为-0.48～0.47 mm,Yt范围为-0.48～0.49 mm,Zt范围为-0.48～0.47 mm,Xr范围为-0.48°～0.47°,Yr范围为-0.48°～0.48°,Zr范围为-0.42°～0.48°.校正后的摆位误差明显小于校正前,其中Xt、Yt、Zt及Xr方向上的摆位误差比较差异有统计学意义(t=2.31,t=3.16,t=-2.45,t=-2.48;P<0.05).ETX残余误差与CBCT所获的验证误差之间的差别很小,且差值占比绝大多数(>91％)在0～1 mm误差的区间上.结论:对于颅内肿瘤FSRT治疗,ETX图像引导系统可以显著减少平移误差和旋转误差,其误差精度与CBCT相差无几,满足高精度的治疗要求.

Esophageal cancer （EC） is one of the leading causes of cancer-related mortality worldwide.It is a highly malignant tumor with a high local recurrence and distant metastasis.Notably,about half of the world’s EC patients occur in China.Smoking,drinking liquor alcohol and eating hot food are the top three risk factors for EC in China. [1]

The association between the red blood cell distribution width (RDW) and hemorrhagic transformation (HT) after thrombolysis in acute ischemic stroke patients remains inconclusive. Our study aimed to assess whether high RDW levels are associated with the occurrence of HT after thrombolysis. Data were consecutively collected and retrospectively analyzed for stroke patients treated with thrombolysis between 1 January 2017 and 31 December 2019. The primary outcomes were the occurrence of HT and symptomatic HT. Among the 286 patients enrolled, 36 (12.6%) developed HT and15 (5.2%) were classified as symptomatic HT. Patients with high RDW levels were associated with a higher percentage of HT and symptomatic HT (P<0.05). The RDW levels in the HT and symptomatic HT groups were also greater compared with the no-HT group (P<0.001). Multivariable logistic regression analysis revealed that high RDW levels were independently associated with an increased risk of HT (adjusted odds ratio 2.5, 95 % CI, 1.74-3.83 P < 0.001). In conclusion, we found that high RDW levels may be an independent predictor of HT in stroke patients after thrombolysis.

目的 比较ExacTrac X-ray(ETX)和锥形束CT(CBCT)两种图像引导系统在肝癌立体定向放射治疗(SBRT)中的摆位误差.方法 选择2019年4月至2020年12月在江苏省苏北人民医院接受SBRT放射治疗的30例肝癌患者,将其随机分为ETX组和CBCT组,每组15例.获取各组校正前后的误差,包括左右(X)、头脚(Y)和前后(Z)方向上的平移误差和绕前后方向上的旋转误差(Zr).结果 ETX组误差校正前后各方向误差比较,差异有统计学意义(P＜0.05).CBCT组校正前后各方向误差比较,差异有统计学意义(P＜0.05).CBCT组与ETX组校正后残留误差值比较,差异无统计学意义(P＞0.05).结论 ETX和CBCT各有优缺点,但两者均能有效减少摆位误差.从减小肝癌SBRT摆位误差角度出发,采用灰度配准的CBCT误差纠正精度较采用骨性配准的ETX更高.

目的 应用高分辨率磁共振(High Resolution Magnetic Resonance Imaging,HRMRI)判断急性缺血性脑卒中患者症状大脑中动脉粥样硬化斑块稳定性,研究影响斑块稳定性的危险因素.方法 连续收集2015年1月-2018年11月于江苏省苏北人民医院神经内科住院的急性缺血性脑卒中患者62例,责任动脉均为大脑中动脉,通过HRMRI评估症状大脑中动脉斑块稳定性,根据斑块稳定性,分为不稳定斑块组44例,稳定斑块组18例,比较两组之间的临床资料,分析影响急性缺血性脑卒中患者症状大脑中动脉粥样硬化斑块稳定性的危险因素.结果 不稳定斑块组与稳定斑块组比较,两组在性别、年龄、糖尿病病史、吸烟史、饮酒史、白蛋白、总蛋白、高密度脂蛋白、尿酸等方面差异无统计学意义,不稳定斑块组高血压病史患者更多;甘油三脂、总胆固醇、低密度脂蛋白、空腹血糖的水平更高,Logistic回归分析提示甘油三脂(r=0.183,95％CI 0.037～0.905,P=0.037)是影响症状性大脑中动脉斑块稳定性的独立危险因素.结论 甘油三脂水平可能与缺血性脑卒中症状性大脑中动脉粥样硬化斑块稳定性独立相关.

目的 紫杉烷联合铂类及氟尿嘧啶类联合铂类均是食管癌的标准治疗方案,但二者之间的优劣尚不明确.本研究旨在应用荟萃分析方法比较紫杉烷联合铂类(taxane plus platinum,TP)与氟尿嘧啶类联合铂类(taxane plus platinum,FP)的同步放化疗治疗不可切除食管癌的临床疗效及安全性.方法 检索PubMed、Embase、中国知网和万方数据库,检索时间截止至2018-12-18,收集所有对比TP与FP的同步放化疗治疗不可切除食管癌的队列研究或者随机对照试验.根据纽卡斯尔-渥大华量表(Newcastle-Ottawa scale,NOS)及Cochrane系统评价手册5.0对纳入的研究进行质量评价.采用RevMan5.3软件对相应的指标进行荟萃分析.结果 36个研究共纳入3 167例患者进行分析,其中随机对照试验20个,队列研究16个.TP的同步放化疗在完全缓解(OR=0.50,95％CI为0.41～0.62,P＜0.001)、客观缓解率(OR=0.45,95％CI为0.37～0.55,P<0.001)、痰病控制率(OR=0.45,95％CI为0.32～0.64,P＜0.001)、无进展生存期(HR=0.72,95％CI为0.63～0.82,P＜0.001)及总生存期(HR=0.78,95％CI为0.69～0.88,P＜0.001)方面均优于FP的同步放化疗.TP的同步放化疗在食管鳞癌患者中的疗效同样明显优于FP的同步放化疗.TP的同步放化疗Ⅲ～Ⅳ度白细胞减少的发生率(OR=1.91,95％CI为1.37～2.67,P＜0.001)要高于FP的同步放化疗,其Ⅲ～Ⅳ度恶心/呕吐(OR=0.53,95％CI为0.32～0.86,P=0.01)及放射性食管炎(OR=0.52,95％ CI为0.39～0.70,P＜0.001)的发生率要低于FP的同步放化疗.结论 TP同步放化疗治疗不可切除食管癌或者食管鳞癌疗效要优于FP同步放化疗,且增加的不良反应在可耐受范围之内.

目的 探讨高龄急性脑梗死患者接受阿替普酶静脉溶栓治疗有效性、安全性和临床预后的影响因素.方法 前瞻性连续纳入江苏省苏北人民医院2016年9月-2018年9月收治入院进行阿替普酶静脉溶栓治疗的急性脑梗死患者,按照年龄将患者分为年龄≥80岁组和年龄<80岁组.比较两组患者入院时、溶栓24h NIHSS评分,6个月mRS评分及死亡率,观察两组溶栓相关出血转化、症状性颅内出血及肺部感染的发生情况.应用多因素Logistic回归分析观察所有患者静脉溶栓预后的独立影响因素.结果 最终共纳入患者119例,男性69例(58.0％),年龄范围46～94岁,平均70.12±10.55岁,入院NIHSS评分4～38分.其中年龄≥80岁患者29例,年龄<80岁患者90例.静脉溶栓后,两组患者溶栓24h NIHSS评分较入院时均明显降低(均P<0.05),两组治疗24h NIHSS评分比较差异无统计学意义;两组的出血转化、症状性颅内出血、肺部感染、6个月预后良好及死亡率比较,差异均无统计学意义.多因素Logistic回归分析显示,入院到静脉溶栓时间、入院时NIHSS评分及肺部感染是脑梗死静脉溶栓6个月预后的独立危险因素(P<0.05),高龄不是影响预后的因素(P>0.05).结论 高龄急性脑梗死患者静脉溶栓治疗安全有效,未增加颅内出血转化风险、死亡率及不良预后.入院到静脉溶栓时间、入院时NIHSS评分及肺部感染是急性脑梗死患者静脉溶栓6个月预后不良的独立危险因素.

Cerebral ischaemia/reperfusion (CI/R) injury is a major challenge due to the lack of effective neuroprotective drugs. Hederagenin (HE) is the aglycone part of saponins extracted from Hedera helix Linné that has exhibited anti-apoptotic and anti-inflammatory effects; however, the role of HE in CI/R has not been elucidated. In this study, mice were intraperitoneally (i.p.) injected with HE (26.5, 53, or 106 μmol/kg body weight) for 3 days after middle cerebral artery occlusion (MCAO). Neural function and brain infarct volume were evaluated. HE treatment attenuated CI/R-induced apoptosis and inflammatory cytokine expression within the infarcted areas. HE treatment also decreased the activation of the MLK3 signalling pathway, which potentiates CI/R damage via the MAPK and NFκB pathways. Due to HE's safety profile, it has potential to be used for the clinical treatment of ischaemic stroke.

目的:比较光学定位系统(optical positioning system,OPS)与锥形束CT(cone beam CT,CBCT)在食管癌放疗中的摆位误差,探讨其临床应用优劣.方法:选取30例食管癌放疗患者,分别采集和比较每例患者在OPS和CBCT摆位引导技术下的摆位误差.将OPS得到的摆位误差设为实验组,将CBCT得到的摆位误差设为对照组.采用SPSS 19.0软件对数据进行统计学分析.结果:在X方向(左右)上,实验组摆位误差为(2.7±0.7)mm,略大于对照组的(2.5±0.3)mm(t=-1.61,P=0.071),2组间差异无统计学意义.而在Y(头脚)及Z(前后)方向上,实验组的摆位误差分别为(2.9±1.1)和(3.9±0.4)mm,均大于对照组的(2.3±1.4)和(3.3±0.7)mm(Z=2.06,P=0.012;t=2.38,P=0.033),2组间差异具有统计学意义.结论:OPS精确性不及CBCT,但具有操作简单、快速和无辐射等优点,将两者有效结合,各取所长,可大大提升摆位效率和摆位精确性,对患者治疗具有重要的积极作用.

目的:分析探讨医用加速器碳纤维治疗床和固定底板对旋转射野吸收剂量的影响.方法:采用同中心SCD100cm照射,X射线能量为6 MV,每个射野机器跳数设置为100 MU,治疗床前后移动距离150 cm,将标准固体水模置于治疗床和固定底板上,使用FC65-G电离室测量吸收剂量,计算不同入射弧度和角度时治疗床及固定底板对X射线的透射率(F)值.分别采用旋转弧和固定野照射,旋转弧照射时将360°均分成4弧、8弧和12弧,记为弧度(ARC)4、ARC8和ARC12;固定野照射时,机架顺时针方向每隔10°测量190°～180°机架角转一周的吸收剂量,记为Fixed 36.结果:ARC4、ARC8和ARC12的3组实验中,射野面积越大,F值越高.固定野照射实验中,射野为10 cm×10 cm和20 cm×20 cm、机架角度为120°和对称方向240°时F值最小,分别为92.21％和92.96％.结论:治疗床在IMRT和VMAT治疗中的剂量衰减明显,基于治疗床和固定底板对固定野照射吸收剂量影响的基础上,对比分析旋转照射野穿透治疗床和固定底板的透射率,可为制作放射治疗计划时提供有益的参考.

Objective To investigate the influence of moderate to severe leukoaraiosis (LA) in prognoses of acute ischemic stroke patients after endovascular treatment.Methods From January 2017 to December 2018, 60 patients with acute ischemic stroke due to anterior circulation large vessel occlusion underwent endovascular treatment and obtained complete vessel recanalization in our hospital were evaluated for degrees of LA severity according to head CT scan and van Swieten scale (2-4 scores were defined as moderate-severe LA). According to modified Rankin scale (mRS) scores 90 d after treatment, the patients were divided into poor prognosis group and good prognosis group. Univariate analysis was used to compare the differences of influencing factors of the two groups. Multivariate Logistic regression analysis was further used to explore the influence of moderate to moderate-severe LA in poor prognosis of patients after endovascular treatment.Results Of the 60 patients, 18 did not have LA, 19 had mild LA, and 23 had moderate-severe LA; 32 had poor prognosis and 28 had good prognosis. Univariate analysis showed that the patients from the poor prognosis group had significantly higher proportion of moderate-severe LA (59. 4％ [19/32]vs. 14.3％ [4/28]), significantly higher baseline National Institutes of Health Stroke Scale (NIHSS) scores ([23.4±10.1]vs. [14.7±7.0]), significantly higher baseline diastolic blood pressure ([87.5±18.9] mmHgvs. [78.3±15.1] mmHg), significantly higherproportion of patients with hypertension history (68.8％ [22/32]vs. 42.9％ [12/28]), and statistically older age ([70.6±9.4] yearsvs. [61.3±12.5] years) than the patients from the good prognosis group (P<0.05). On multivariable Logistic regression analysis, the presence of moderate-severe LA (OR=5.032, 95％CI: 1.026-24.679,P=0.046) and baseline NIHSS scores were independent risk factors for poor prognosis of patients after endovascular treatment.Conclusion Patients with acute ischemic stroke accompanied with moderate-severe LA are more likely to have poor prognosis after endovascular treatment.

The occurrence,development and reperfusion treatment of ischemic stroke may damage the structure and function of the blood-brain barrier,leading to increased permeability of the blood-brain barrier,and then having cerebral edema or hemorrhagic transformation,and finally resulting in poor outcome.Quantitative assessment of blood-brain barrier permeability is now available.This article reviews the assessment methods of blood-brain barrier permeability and their application in patients with ischemic stroke.

目的 基于Varian Eclipse三维计划系统的直肠癌调强适形放射治疗(intensity-modulated radiotherapy,IMRT)中,存在计算算法、多叶准直器(multileaf collimator,MLC)运动方式和X射线能量3种条件变量.现有文献通常采用单变量法对某一条件变量的剂量学进行了研究,并未考虑变量之间的相互影响,存在一定不足.本研究结合了单变量法和多变量法进行剂量学对比分析,旨在探索Eclipse中直肠癌IMRT的最佳变量组合模式.方法 采用单变量法研究3种条件变量对放疗计划评估参数的影响,这些评估参数包括靶区的Dmean、适形指数(conformal index,CI)和均匀性指数(homogeneity index,HI),以及膀胱D50、脊髓Dm小肠Dmax和股骨头D5.在此基础上进行多变量研究,即将3种条件变量中的优变量和劣变量各自串联组成A、B2个对照组,并统计分析A组和B组的计划评估参数.结果 (1)算法变量研究中,各项异性算法(anisotropic analytical algorithm,AAA)与笔形束卷积算法(pencil beam convolution,PBC)相比,计划靶区体积(planning target volume,PTV)的Dmean偏大(Z=-3.264,P＜0.001),CI偏大(t=3.295,p=0.004);危及器官(organ at risk,OAR)均偏小,P＜0.05.(2) MLC运动方式变量研究中,动态调强(sliding window,SW)与静态调强(multiple static segments,MSS)相比,PTV的Dmean更接近处方剂量(t=2.479,P=0.023),OAR中小肠Dmax、脊髓Dmax和膀胱D50也偏小,P＜0.05.(3)X射线能量变量研究中,15与6 MV相比,PTV的Dmean偏大(t=15.153,P＜0.001),CI偏大(t=6.065,P＜0.001),和HI也更接近1(t=-4.807,P＜0.001);OAR中小肠Dmax偏小(Z=-3.92,P＜0.001),脊髓Dmax偏小(t=-4.225,P＜0.001),股骨头D5偏小(Z=-2.962,P=0.008),膀胱D50偏大,t=10.599,P＜0.001.(4)多变量串联组合研究中,A组与B组相比,A组PTV的Dmean偏大(Z=-3.17,P=0.002),CI偏大(Z=18.118,P＜0.001),和HI也更接近1(t=-14.899,P＜0.001);OAR各器官均偏小,P＜0.05.结论 利用Eclispe设计直肠癌IMRT计划时,采用AAA、SW以及15 MV组成的多变量模式能最大程度的增大放疗增益比,是一种最佳变量组合模式.

目的:探讨不同宽度多叶准直器(MLC)叶片对食管癌调强放射治疗(IMRT)的剂量学影响,为食管癌IMRT提供更加合理的参考.方法:选取40例食管癌调强病例,采用瓦里安Eclipse13.5治疗计划系统设计放射治疗计划.在MLC的中间区域以及边缘区域进行IMRT优化设计,分别对靶区的基本参数以及危及器官的受量进行比较,分析出两组计划的差异;利用剂量体积直方图比较靶区、肺、心脏和脊髓照射剂量和体积.结果:选择在MLC的中间区域进行优化,靶区的Dmean更高,且均匀性以及适形性更优,心脏受量更高,心脏MLC中间区域的Dmean和V30值均低于MLC边缘区域,其差异有统计学意义(t=-3.531,t=-3.551;P<0.05);双肺MLC中间区域的Dmean、V5、V10、V20及V30略高于MLC边缘区域,其差异有统计学意义(t=4.773,t=6.282,t=0.047,t=4.536,t=2.075;P<0.05),脊髓剂量MLC中间区域的Dmax值要高于MLC边缘区域,其差异有统计学意义(t=-5.980,P<0.05).结论:在肺部、脊髓以及心脏等危及器官都能达到剂量限值的基础上,应尽量选择MLC的中间区域进行优化,使其获得良好的靶区剂量分布,提高肿瘤的控制率.