胸部肿瘤三维适形放疗摆位的重复性研究

目的:研究胸部肿瘤三维适形放疗的摆位误差大小和影响因素,为胸部肿瘤适形放疗计划设计时CTV外放PTV提供参考数据.方法:21例胸部肿瘤患者接受三维适形放疗.男12例,女9例.其中食管癌9例,肺癌7例,乳腺癌5例.首次摆位后,去掉体膜,在患者体表沿激光十字画出三个等中心点的坐标位置,并以该三个坐标为标准坐标,测量前后、头脚、左右方向摆位误差.每例病例连续测量5次,共计摆位105次.所有病例分为两组,A组11例,测量55次,未在体表标记体膜相对位置.B组10例,测量50次,CT模拟定位时在体表标记体膜相对位置.结果:人与人间以及次与次间均存在一定差别.头脚方向摆位误差最大,腹背方向次之,左右方向最小.B组摆位误差左右方向为(2.2±1.9)mm,头脚方向为(4.3±2.6)mm,腹背方向为(2.6±1.7)mm.与A组比较,误差在Y、Z方向有显著性差异.结论:CT模拟定位时,在体表标记体膜的相对位置可减少三维适形放疗的摆位误差.胸部放疗的CTV-PTV扩边范围(MPTV)应适当扩充为左右方向5.4mm、头脚方向8.3mm和腹背方向5.5mm.     

盆腔肿瘤三维适形放疗摆位重复性研究

目的研究盆腔肿瘤三维适形放疗的摆位误差大小,为盆腔肿瘤适形放疗计划设计时CTV外放PTV提供参考数据。方法接受放疗的直肠癌病例3例和前列腺癌病例2例,均为男性,行俯卧位盆腔三维适形放疗。每例病例治疗时身下垫有孔泡沫板,连续5 d摆位照射,每次摆位时在患者体表固定点粘贴定位金点,热塑成型固定膜固定,加速器机头插入与治疗中心一致的定位“+”字刻度板,照射正侧位治疗验证片各1张,共计摆位25次,照射治疗验证片50张。以第1次摆位片为标准,计算前后、头尾、左右方向摆位误差。结果5例病例25次摆位误差,人与人间以及次与次间均存在一定差别。前后方向摆位误差最大,平均值为(0．98±0．68)cm,有9次摆位误差≥1 cm,占测算次数的45%,其中2次误差≥2 cm；头尾方向摆位误差为[(0．50～0．70)±0．45]cm,正位测定误差小于侧位,分别为(0．51±0．46)、(0．70±0．45)cm,正位和侧位分别有4次和7次摆位误差≥1 cm；左右方向误差最小,为(0．37±0．28)cm,仅1次误差≥1 cm。结论在三维适形技术放疗盆腔肿瘤时．左右方向摆位误差最小,头尾方向居中,前后方向最大；CTV外放PTV应考虑左右方向0．5 cm,头尾方向1．0 cm,前后方向1．5 cm。     

胸部肿瘤三维适形放疗剂量造影剂影响的研究

目的:探讨CT造影剂对胸部肿瘤三维适形放疗剂量的影响.方法:共有40例患者入组,其中食管癌患者34例,肺癌患者6例,中位年龄62岁.在相同扫描条件下分别行CT平扫及增强扫描.在图像融合状态下,分别勾画大体靶区(GTV)、临床靶区(CTV)、计划靶区(PTV)以及危及器官,以平扫图像为基础图像进行剂量计算和计划优化,PTV边缘剂量1.8～2.0 Gy/次,总量45～66 Gy,并以此计划进行治疗.利用计划系统图像融合的功能,将在平扫图像(C-)上勾画的靶区及照射野设计复制到增强图像上,在增强图像(C+)上重新进行剂量计算;分别比较C+和C-图像中相对应的单次治疗照射野MU的不同(按照2 Gy/次计算),肿瘤中心点的剂量、肿瘤边缘点的CT值及剂量的不同;并进行统计学分析.结果:40例患者共有205个照射野,其平扫及增强图像射野MU分别为284.55±63.64和283.00±63.21,P=0.120;肿瘤中心点的剂量分别为平扫(45.219 5±9.561 4) Gy、增强(45.211 7±9.614 5)Gy,P=0.772;肿瘤边缘点的剂量分别为平扫(43.837 2±9.304 9)Gy、增强(42.904 5±9.164 5)Gy,P=0.001;边缘点的CT值分别为平扫(140.83±40.55) HU、增强(39.20±20.82) HU,P=0.00.结论:采用适当的扫描条件,对于胸部肿瘤,可以采用直接增强扫描的方式进行CT定位,使用CT增强扫描对放疗计划的优化影响不明显.     

多靶区三维适形放疗在胸部肿瘤的临床应用

目的 研究胸部多病灶肿瘤行多靶区三维适形放射治疗的可行性及应用价值。方法 对36例胸部原发肿瘤肺内纵隔转移或双肺多发转移瘤等晚期肿瘤,采用多靶区三维适形放射治疗,优化指标：照射靶区尽可能采用PET/CT定位，靶区以2～4个为宜,采用共面或非共面多野照射，每次剂量2Gy,5次/周,或5～8Gy/次,3次/周，均为90%剂量曲线包绕PTV，总照射剂量或生物等效剂量70～80Gy，在放疗结束后2月行胸部CT或PET/CT进行评价。结果 36例患者中，2例病灶完全消失（CR），23例病灶明显缩小（PR），有效率（CR＋PR）69.4%,放疗中未出现明显放射性肺炎、放射性食管炎。结论晚期胸部肿瘤或转移瘤应用三维适形放射治疗采用多靶区治疗，局部控制率高，有较好的近期疗效，早期并发症低，患者可耐受。     

体部三维适形放射治疗中的摆位技术体会

随着放射治疗学的发展,三维适形放疗（3DCRT）在世界范围内已逐渐成为放射治疗的常规技术,它能使治疗区的形状与靶区的形状一致,从三维方向上进行剂量分布的控制,能提高局部控制率,减少正常组织的照射剂量,保证精确的体位固定技术、定位和重复摆位是实现3DCRT的根本措施。本文通过我院2000年5月一2005年5月用3DCRT治疗的192例胸腹部肿瘤的定位和摆位中遇到的问题进行了总结分析,目的是探讨在胸腹部肿瘤的定位和摆位过程中应注意的问题,从而提高3DCRT的定位和摆位精度。     

胸段食管癌三维适形放疗摆位误差研究

目的 应用电子射野影像装置(EPID)测量胸段食管癌三维适形放疗(3DCRT)的摆位误差,推算PTV与CTV之间的间隙.方法 对41例胸段食管癌患者每周拍摄1次正侧位EPI,通过比较EPI和数字重建影像(DRR)的差异来测量摆位误差.根据公式计算出PTV与CTV之间的间隙.采用自身配对设计对22例接受根治性放疗患者应用不同PTV与CTV的间隙值分别设计两套模拟治疗计划,A组x、y和z轴均为10 mm,B组采用本研究结果 的间隙值.应用配对t检验或Wilcoxon符号秩检验来比较两套计划间的差异.结果 x、y、z轴的PTV与CTV的间隙值分别为8.72、10.50、5.62 mm.两套模拟计划间的脊髓最高照射剂量不同,A计划为(4638.7±1449.6)cGy,B计划为(4310.2±1528.7)cGy(t=5.48,P=0.000);脊髓并发症概率也不同,A计划为4.82%±5.99%,B计划为3.64%±4.70%(Z=-2.70,P=0.007).结论 笔者单位胸段食管癌接受3DCRT时在x,y和z轴上的PTV与CTV之间的间隙值分别为8.72、10.50、5.62 mm;与3个轴均为10 mm的间隙值相比应用本研究结果 制定治疗计划可更有效地保护脊髓.     

胸段食管癌三维适形放疗摆位误差研究

Objective To study the setup errors in three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal carcinoma using electronic portal imaging device(EPID) and calculate the margins from CTV to PTV. Methods Forty-one patients with thoracic esophageal carcinoma who received 3DCRT were continuously enrolled into this study. The anterior and lateral electronic portal images (EPI) were aquired by EPID once a week. The setup errors were obtained through comparing the difference between EPI and digitally reconstructed radiographs(DRR). Then the setup margins from CTV to PTV were calculat-ed. By using self paired design,22 patients received definitive radiotherapy with different margins. Group A: the margins were 10 mm in all the three axes;Group B: the margins were aquired in this study. The differ-ence were compared by Paired t-test or Wilcoxon signed-rank test. Results The margins from CTV to PTV in x,y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. Between the group A and group B, the difference of the maximum dose of the spinal cord was significant(4638.7 cGy±1449.6 cGy vs. 4310.2 cGy±1528.7 cGy; t=5.48, P=0.000), and the difference of NTCP for the spinal cord was also significant (4.82%±5.99% vs. 3.64%±4.70%;Z=-2.70,P=0.007). Conclusions For patients with tho-racic esophageal carcinoma who receive 3DCRT in author's department,the margins from CTV to PTV in x, y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. The spinal cord could be better protected by using these setup margins than using 10 mm in each axis.     

胸段食管癌三维适形放疗摆位误差研究

Objective To study the setup errors in three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal carcinoma using electronic portal imaging device(EPID) and calculate the margins from CTV to PTV. Methods Forty-one patients with thoracic esophageal carcinoma who received 3DCRT were continuously enrolled into this study. The anterior and lateral electronic portal images (EPI) were aquired by EPID once a week. The setup errors were obtained through comparing the difference between EPI and digitally reconstructed radiographs(DRR). Then the setup margins from CTV to PTV were calculat-ed. By using self paired design,22 patients received definitive radiotherapy with different margins. Group A: the margins were 10 mm in all the three axes;Group B: the margins were aquired in this study. The differ-ence were compared by Paired t-test or Wilcoxon signed-rank test. Results The margins from CTV to PTV in x,y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. Between the group A and group B, the difference of the maximum dose of the spinal cord was significant(4638.7 cGy±1449.6 cGy vs. 4310.2 cGy±1528.7 cGy; t=5.48, P=0.000), and the difference of NTCP for the spinal cord was also significant (4.82%±5.99% vs. 3.64%±4.70%;Z=-2.70,P=0.007). Conclusions For patients with tho-racic esophageal carcinoma who receive 3DCRT in author's department,the margins from CTV to PTV in x, y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. The spinal cord could be better protected by using these setup margins than using 10 mm in each axis.     

胸段食管癌三维适形放疗摆位误差研究

Objective To study the setup errors in three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal carcinoma using electronic portal imaging device(EPID) and calculate the margins from CTV to PTV. Methods Forty-one patients with thoracic esophageal carcinoma who received 3DCRT were continuously enrolled into this study. The anterior and lateral electronic portal images (EPI) were aquired by EPID once a week. The setup errors were obtained through comparing the difference between EPI and digitally reconstructed radiographs(DRR). Then the setup margins from CTV to PTV were calculat-ed. By using self paired design,22 patients received definitive radiotherapy with different margins. Group A: the margins were 10 mm in all the three axes;Group B: the margins were aquired in this study. The differ-ence were compared by Paired t-test or Wilcoxon signed-rank test. Results The margins from CTV to PTV in x,y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. Between the group A and group B, the difference of the maximum dose of the spinal cord was significant(4638.7 cGy±1449.6 cGy vs. 4310.2 cGy±1528.7 cGy; t=5.48, P=0.000), and the difference of NTCP for the spinal cord was also significant (4.82%±5.99% vs. 3.64%±4.70%;Z=-2.70,P=0.007). Conclusions For patients with tho-racic esophageal carcinoma who receive 3DCRT in author's department,the margins from CTV to PTV in x, y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. The spinal cord could be better protected by using these setup margins than using 10 mm in each axis.     

胸段食管癌三维适形放疗摆位误差研究

Objective To study the setup errors in three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal carcinoma using electronic portal imaging device(EPID) and calculate the margins from CTV to PTV. Methods Forty-one patients with thoracic esophageal carcinoma who received 3DCRT were continuously enrolled into this study. The anterior and lateral electronic portal images (EPI) were aquired by EPID once a week. The setup errors were obtained through comparing the difference between EPI and digitally reconstructed radiographs(DRR). Then the setup margins from CTV to PTV were calculat-ed. By using self paired design,22 patients received definitive radiotherapy with different margins. Group A: the margins were 10 mm in all the three axes;Group B: the margins were aquired in this study. The differ-ence were compared by Paired t-test or Wilcoxon signed-rank test. Results The margins from CTV to PTV in x,y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. Between the group A and group B, the difference of the maximum dose of the spinal cord was significant(4638.7 cGy±1449.6 cGy vs. 4310.2 cGy±1528.7 cGy; t=5.48, P=0.000), and the difference of NTCP for the spinal cord was also significant (4.82%±5.99% vs. 3.64%±4.70%;Z=-2.70,P=0.007). Conclusions For patients with tho-racic esophageal carcinoma who receive 3DCRT in author's department,the margins from CTV to PTV in x, y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. The spinal cord could be better protected by using these setup margins than using 10 mm in each axis.     

三维适形放射治疗前列腺增生症对直肠损伤的实验研究

目的:观察在三维适形放射治疗犬自发性前列腺增生中直肠损伤,为临床提供放射性直肠炎诊治依据。方法:分别选择7-15岁雄性合格BPH动物模型8只为实验组,5只为空白对照组。实验组应用立体定向放射治疗前列腺。勾画整个前列腺为靶区,以90％的等剂量曲线包绕靶区,单次剂量2Gy,每周照射5次,共7次,总剂量14Gy。应用DVH图测定直肠受照体积与剂量。照射开始后6周分别取与前列腺紧邻受到照射的直肠和空白对照组直肠。分别应用光镜、扫描电镜和透射电镜观察直肠组织形态的变化。结果:按照RTOG(Radiation Therapy Oncology Group,美国肿瘤放射治疗协作组织)急性放射损伤标准,照射后犬直肠放射性损伤评定为0-1级。与对照组比较,照射后直肠HE染色光镜下可见,上皮及基底层结构完整,上皮细胞有少量脱落;与对照组比较,照射后扫描电镜下,可见上皮细胞排列基本整齐,偶见细胞脱落,肠壁有分泌物;透射电镜下可见基底膜破损、松散,上皮细胞、黏膜肌层细胞、黏膜纤维细胞凋亡。结论:放射性直肠炎的上皮细胞凋亡脱落、 基底膜松散破损、黏膜层肌细胞及纤维细胞凋亡等组织病理改变在低于目前公认的照射剂量阈值之下已经出现。     

鼻咽癌常规放射治疗加后程三维适形放射治疗近期疗效观察

目的：探讨鼻咽癌后程三维适形放射治疗（3DCRT）的疗效.方法：40例初治无远处转移的鼻咽癌患者,采用分两阶段对原发灶及颈部放射治疗.第一阶段用面颈联合野常规放疗DT 38Gy,第二阶段用3DCRT DT 30-36Gy,鼻咽癌原发灶总剂量70～74Gy,颈部用切线野常规分割放疗,射野上界保持与主野下界衔接,对颈淋巴结阴性照射DT 50Gy,淋巴结阳性照射DT66-70Gy.结果：局部肿瘤消退率（有效率） 100％,完全缓解率93.85％,1年生存率100％.无严重并发症发生.结论：鼻咽癌常规放射治疗加后程三维适型放射治疗近期疗效满意.     

立体定向适形放疗剂量对晚期胆管癌治疗疗效的影响

目的：探讨立体定向适形放疗(3D-CRT)剂量对不可切除的胆管癌治疗疗效的影响。方法：对48例不能手术切除的局部晚期胆管癌患者采用3D-CRT技术，根据放疗剂量分为3组，低剂量组12例，DT33～39Gy，中等剂量组23例，DT40—58Gy，高剂量组13例，DT59．4—68Gy。低剂量组3Gy／次，中等剂量组及高剂量组1．8—2．0Gy／次，5次／周。结果：所有患者局部复发的中位时间是10月，中位总生存期是12月。影像学显示24例(50％)疾病进展，其中21例(87．5％)以局部复发作为疾病进展的第一影像学证据，其余3例出现远处转移。3组间局部复发时间(P=0．220)及中位生存时间(P=0．232)差异无显著性。急性胃肠道反应发生率在各放疗剂量组差异无显著性(P=0．485)。结论：局部进展是本组胆管癌治疗失败的主要原因。虽然因本研究病例数较少不足以进到统计处理，但高放疗剂量组具有局部控制率较高、总生存期较长的趋势。     

食管癌三维适形放射治疗剂量学与放射性肺炎发生相互关系的研究

目的:通过食管癌常规放射治疗与三维适形放射治疗的技术对比研究,比较应用不同外照射技术时肿瘤靶区适形指数的差异,以及肺等正常组织受照射容积剂量与放射性肺炎并发症发生概率(NTCP)的关系.方法:应用三维治疗计划系统,对28例胸中段EPC分别设计三种照射技术(A:常规3野;B:适形3野;C:适形5野).比较在同一处方剂量(66 Gy)时肿瘤靶区的适形指数,全肺受照射剂量与肺的NTCP的差异.结果:A、B、C三种照射技术比较:1)靶区的适形指数从0.55±0.09提高至0.76±0.04 和 0.78±0.06.2)肺平均剂量从(16.54±2.35) Gy降低至(13.26±1.93) Gy和(3.38±1.61) Gy;肺的V20从(32.95±6.43)%降低至(23.01±6.25)%和(24.8±4.47)%;肺的V30从(17.25±4.96)% 降低至(12.18±3.66)%和(6.75±2.93)%.3)肺的 NTCP从(6.9±6.86)%降低至(1.14±1.11)%和(1±1.02)%.A、B和C三种照射技术比较差异均有统计学意义,P=0.000.结论:三维适形放射治疗技术的靶区剂量分布较理想,显著降低正常肺的照射体积和剂量,减少放射性肺炎NTCP.     

食管鳞癌三维适形放疗疗效及预后影响因素分析

目的:观察食管鳞癌三维适形放疗的疗效及预后因素。方法:回顾性分析我院2006年1月至2013年6月首程行三维适形放疗的食管鳞癌患者140例,采用Kaplan-Meier法计算生存率,预后影响因素行Log-Rank法单因素分析和Cox法多因素分析。结果:三维适形放疗是治疗食管癌的有效手段,全组食管癌患者1、3、5年生存率为64.3%、39.3%、23.1%,三个民族之间近远期生存率无明显差异（P>0.05）。3DCRT治疗三个民族中晚期食管癌患者的近远期疗效相似。影响3DCRT治疗效果的单因素是性别、治疗前CT可见食管病变长度、TNM分期、是否联合化疗、GTV体积,60Gy与66Gy两种放疗剂量的患者预后有统计学差异。多因素分析:性别、食管病变长度、T分期、N分期和GTV体积都独立影响食管癌预后。结论:相对50Gy放疗剂量来说,更高剂量的食管癌患者放疗后的预后没有改善,影响生存的因素有食管病变长度、GTV体积、T分期、N分期、序贯化疗。     

三维立体定向适形放射治疗在治疗肝脏转移性肿瘤中的应用

目的探讨三维立体定向适形放射治疗在肝脏转移性肿瘤中的应用价值。方法用三维立体定向适形放射技术治疗转移性肝瘤，优化指标：每次剂量2—3Gy时，90％的等剂量面包绕PTV；每次剂量8Gy时，70％～80％等剂量面包绕PTV平均肝脏剂量小于30Gy。给量2Gy／次，1次／日，5天／周。照射次数25～30次，总剂量为50Gy～60Gy。或者8Gy／次，3次／周，共3次。结果在放疗结束后2个月用腹部CT进行评价，有效率(CR PR)50％。3年局部无进展生存率75％。放疗中后无严重并发症发生。结论三维立体定向适形放射治疗在不增加治疗并发症基础上，能明显提高肝转移性癌的局部控制率。我们认为晚期病人出现肝转移时，在其它部位病灶尚稳定的情况下可选择三维立体定向适形放射治疗。     

三维适形放射治疗定位新技术在食管癌中的应用

目的:分析常规食管癌定位技术是否能够优化射野设计和提高CTV定位的准确率,探讨新定位技术在食管癌中的应用.方法:患者采用CT扫描前和扫描过程中口服一定量的阴性造影剂和阳性造影剂准确显示CTV.结果:运用该项定位技术可以相对准确测得肿块的长度和等中心,并且能够精确获得食管癌狭窄段位置、肿块大小及食管壁破坏程度,同时能清晰测得食管内、外侧壁.结论:该方法为精确放射治疗提供条件,提高了食管癌三维适形放疗的精确度.