食管癌分次放疗期间靶区不确定性初步研究

Objective To investigate the changes of target during fractionated radiotherapy for e-sophageal cancer, and to assess their impact on the implementation of radiotherapy. Methods Fourteen pa-tients with unresectable esophageal cancer were enrolled to receive full course conformal radiotherapy. CT scans were performed after every ten fractions. New targets (GTV) were delineated on repeated CT scans. Then the pretreatment radiotherapy plans were copied to the new targets to investigate the conformity between the new GTV and the plans. Results The majority of the GTVs decreased with the increasing fractions dur-ing radiotherapy. However, GTVs of 35.7% (5/14) patients increased by 2.0%-37.7% at the tenth frac-tion. The PTVs covered by 95% isodose curve at the time of pretreatment,tenth fraction,twentieth fraction and thirtieth fraction were 97.81%±1.53%, 91.95%±5.25%, 94.27%±4.23% and 94.03%±6.45%, respectively. Moreover, at tenth, twentieth and thirtieth fraction, there were 6,5, and 4 patients whose PTVs covered by 95% isodose curve were below 95%, respectively. Conclusions There are signifi-cant target changes during fractionated radiotherapy for esophageal cancer, which may result in uncertainties of radiotherapy implementation.     

食管癌分次放疗期间靶区不确定性初步研究

Objective To investigate the changes of target during fractionated radiotherapy for e-sophageal cancer, and to assess their impact on the implementation of radiotherapy. Methods Fourteen pa-tients with unresectable esophageal cancer were enrolled to receive full course conformal radiotherapy. CT scans were performed after every ten fractions. New targets (GTV) were delineated on repeated CT scans. Then the pretreatment radiotherapy plans were copied to the new targets to investigate the conformity between the new GTV and the plans. Results The majority of the GTVs decreased with the increasing fractions dur-ing radiotherapy. However, GTVs of 35.7% (5/14) patients increased by 2.0%-37.7% at the tenth frac-tion. The PTVs covered by 95% isodose curve at the time of pretreatment,tenth fraction,twentieth fraction and thirtieth fraction were 97.81%±1.53%, 91.95%±5.25%, 94.27%±4.23% and 94.03%±6.45%, respectively. Moreover, at tenth, twentieth and thirtieth fraction, there were 6,5, and 4 patients whose PTVs covered by 95% isodose curve were below 95%, respectively. Conclusions There are signifi-cant target changes during fractionated radiotherapy for esophageal cancer, which may result in uncertainties of radiotherapy implementation.     

食管癌分次放疗期间靶区不确定性初步研究

Objective To investigate the changes of target during fractionated radiotherapy for e-sophageal cancer, and to assess their impact on the implementation of radiotherapy. Methods Fourteen pa-tients with unresectable esophageal cancer were enrolled to receive full course conformal radiotherapy. CT scans were performed after every ten fractions. New targets (GTV) were delineated on repeated CT scans. Then the pretreatment radiotherapy plans were copied to the new targets to investigate the conformity between the new GTV and the plans. Results The majority of the GTVs decreased with the increasing fractions dur-ing radiotherapy. However, GTVs of 35.7% (5/14) patients increased by 2.0%-37.7% at the tenth frac-tion. The PTVs covered by 95% isodose curve at the time of pretreatment,tenth fraction,twentieth fraction and thirtieth fraction were 97.81%±1.53%, 91.95%±5.25%, 94.27%±4.23% and 94.03%±6.45%, respectively. Moreover, at tenth, twentieth and thirtieth fraction, there were 6,5, and 4 patients whose PTVs covered by 95% isodose curve were below 95%, respectively. Conclusions There are signifi-cant target changes during fractionated radiotherapy for esophageal cancer, which may result in uncertainties of radiotherapy implementation.     

宫颈癌放疗计划中小肠3种勾画方法比较

目的 基于3种方法勾画小肠并分别制定放疗计划,评估小肠肠管受照剂量体积差异及3种勾画方法的可行性。方法 选择宫颈癌初期患者12例,处方剂量45 Gy分25次,分别以勾画小肠肠管法(BL)、肠袋法(BB)和勾画整个腹膜腔法(PS)为目标函数制定放疗计划,评估PTV的D_max、D_mean、CI、HI和小肠肠管D_max、D_mean、V₅—V₄₅差异并配对t检验。结果 BL与BB计划相比,PTV在D_max、CI、HI上相近(P=0.171、0.076、0.192),D_mean不同(P=0.017);小肠肠管D_max不同(P=0.038),V₅—V₄₅相近(P=0.315~0.855)。BL与PS计划下相比,PTV的D_max、D_mean、CI、HI均不同(P=0.033、0.044、0.046、0.041),小肠肠管D_max不同(P=0.013),V₅—V₄₅相近(P=0.416~0.977)。从计划结果看要想使小肠肠管V₄₀≤15%,肠袋和腹膜腔V₄₀应≤20%。结论 采用3种勾画方法制定的放疗计划都能使小肠肠管达到相似剂量体积,从PTV的CI、HI及小肠肠管D_max控制方面,勾画肠袋较腹膜腔似乎更好一些。     

乏氧诱导因子-1α抑制剂YC-1对乏氧脑胶质瘤SHG44细胞株的放射增敏作用

目的探讨乏氧诱导因子1α（HIF-1α）抑制剂YC-1对乏氧脑胶质瘤SHG44细胞株的放射增敏作用及其作用机制。方法选择脑胶质瘤SHG44细胞株,分别在常氧（20%O2）、乏氧（1%O2）12 h和24 h、乏氧＋YC-112 h和24 h这5种不同条件下培养,采用Western blot检测HIF-1α的表达水平;细胞克隆形成实验绘制细胞存活曲线以观察其放射敏感性;利用剂量分割法绘制亚致死性损伤修复曲线以观察其修复能力。结果脑胶质瘤SHG44细胞株在乏氧12 h和24 h与常氧培养相比,HIF-1α的表达水平显著升高,放射敏感性下降,其氧增强比分别为1.22和1.37,进一步统计分析发现其亚致死性损伤修复能力升高,且在间隔8、10、12 h照射时,差异均有统计学意义（均P〈0.05）;而当在乏氧12 h和24 h培养的同时加用YC-1时,HIF-1α的表达水平则显著降低,放射敏感性升高,其增强因子均为1.27,进一步统计分析也发现其亚致死性损伤修复显著降低,且在间隔8、10、12 h照射时,差异均有统计学意义（均P〈0.05）。结论 YC-1能明显提高乏氧脑胶质瘤SHG44细胞株的放射敏感性,其机制可能与YC-1能抑制细胞的亚致死性损伤修复能力有关。     

烟酰胺配合放射治疗鼻咽癌的临床初步研究

目的：探讨常规分割放射治疗联合大剂量烟酰胺治疗鼻咽癌的可行性，观察主要毒性反应和初步疗效。方法：从1999年9月至2000年8月共有20例患入组研究，采用常规分割放射治疗，同时在鼻咽原发灶每次放疗前30～60分钟口服烟酰胺片，单次剂量为50mg／kg。结果：20例患有18例完成预定的治疗方案，完成率为90％，。主要治疗毒性为：Ⅲ级口腔粘膜急性反应发生率为40％(8／20)；Ⅲ级照射野区皮肤急性反应发生率为20％(4／20)；Ⅲ级消化道急性反应发生率为20％，(4／20)，主要表现为恶心和呕吐。所有患中无一例出现Ⅳ级毒副反应。2例出现轻度的骨髓抑制。治疗后无明显的肝脏、肾脏和心脏毒性。治疗后鼻咽病灶的有效率(CR PR)为100％，其中CR率为85%(17／20)；2年鼻咽原发灶控制率、无远处转移率和生存率分别为94．7％、95％和95％。结论：用常规分割放射治疗联合大剂量烟酰胺治疗鼻咽癌的方案可行，近期疗效较满意。     

电子线射野勾画模拟架的制作与临床应用

医用电子直线加速器在肿瘤放射治疗中已应用了半个世纪,在我国也应用了20多年。放射治疗主要利用其产生的电子线和X线,这两种射线在肿瘤的放射治疗中都占有非常重要的地位,但在照射方法上存在着明显差异,其中电子线照射时必须应用限光筒,故需在加速器上进行照射野轮廓的勾画工作,这样可能引起一些工作上的不便,为此作者于     

脑胶质瘤术后放射治疗预后因素研究进展

胶质瘤是颅内肿瘤中最常见的一种,好发于青壮年且大多数为恶性胶质瘤.影响脑胶质瘤预后的临床因素很多,其中年龄、KPS、临床分期和病理类型是报道较为一致独立预后因素.但相比而言,综合分析能更准确地判断预后、更科学地选择治疗手段和合理分配医疗资源,是今后脑胶质瘤临床预后因素分析的研究方向.     

磁共振成像检测肿瘤乏氧

研究证实动态增强磁共振成像(DCE-MRI)、血氧水平依赖性磁共振成像(BOLD-MRI)、电子顺磁共振(EPR)血氧测定法、overhauser-磁共振成像(OMRI)、氟碳磁共振成像(19F-MRI)等技术能安全有效地检测肿瘤乏氧.这些显像技术可以用于预测肿瘤预后、进行个体化治疗和预测以及监测治疗的反应性.