兔VX2 肝癌放疗后的MR扩散加权成像特征与细胞凋亡情况  

Diffusion-weighted MR and apoptosis research in rabbit models of hepatic VX2 tumors after radiotherapy

作　　者：江新青[1] 刘真 魏新华[1] 吴红珍[1] 陈亮[1] 徐海侠[1] 

机构地区：[1]广州医学院附属广州市第一人民医院放射科,510180

出　　处：《中华放射学杂志》2010年第5期540-544,共5页Chinese Journal of Radiology

基　　金：广东省科技厅基金资助项目（2004836001043）

摘　　要：目的 研究VX2肝癌三维立体定向适形放疗后的DWI特征及肿瘤细胞凋亡情况.方法 成功制成60只兔肝癌模型后,待瘤体直径≥1 cm时,应用随机数字表法随机抽取40只瘤兔进行放疗,将放疗后40只兔用同样方法随机分成4组,每组10只,各组兔分别于放疗后1、5、10和15 d进行MR扫描,另20只作为对照组,不行放疗,随机分配到各组中,测量VX2肿瘤、肝脏ROI的ADC值,并计算两者比值.肿瘤标本行DNA缺口末端标记（TUNEL）法测定肿瘤细胞凋亡情况,计算凋亡指数（AI）,采用方差分析比较组间差异有统计学意义后,再采用SNK检验分别比较不同放疗时间点各组ADC比值和AI,不同放疗时间点放疗组与对照组之间比较采用两样本t检验.结果 放疗后1、5、10和15 d,放疗组ADC比值分别为0.74±0.15（8只）、1.04±0.09（7只）、1.43±0.12（7只）、1.25±0.23（8只）,差异有统计学意义（F=24.221,P＜0.01）;相应对照组ADC比值分别为0.78±0.07（5只）、0.79±0.07（4只）、0.83±0.14（4只）、0.97±0.19（4只）.2组放疗后5和10 d差异有统计学意义（t值分别为4.417和7.259,P值均＜0.01）,放疗后1和15 d差异无统计学意义（t值分别为0.569和1.957,P值均＞0.05）.1、5、10和15 d放疗组凋亡指数分别为0.39±0.13（8只）、0.29±0.08（7只）、0.28±0.07（7只）、0.58±0.19（8只）,差异有统计学意义（F=8.128,P＜0.05）;相应对照组凋亡指数分别为0.26±0.13（5只）、0.18±0.03（4只）、0.16±0.06（4只）、0.18±0.08（n=4）,差异无统计学意义（F=1.006,P＞0.05）;2组放疗后5、10和15 d差异有统计学意义（t值分别为2.348、2.386和3.756,P值均＜0.05）,放疗后1 d差异无统计学意义（t值为1.716,P＞0.05）.结论 DWI可以反映兔VX2肝放疗后不同时间点细胞凋亡的动态变化.Objective To investigate the imaging characteristic of DWI in rabbit models of hepatic VX2 tumors after three-dimensional stereotactic conformal radiation therapy, and the characteristics of apoptosis after radiotherapy. Methods Sixty hepatic VX2 tumor models were successfully created. After the tumor grew to more than 1 cm in diameter, 40 tumor models were treated with SCRT and then divided into four groups using random number table. The remaining 20 tumor models were used as controls and randomly assigned to each group. MR scanning were performed at different time points （ 1 st day, 5 th day, 10 th day, 15 th day） for each group respectively. ROIs of the VX2 tumor tissues and normal liver tissue were taken and ADC values were measured to calculate their ratios. Cell apoptesis were determined by using TUNEL method. ADC values with their ratios and the apoptotic index were analyzed using one-way analysis of variance and SNK test was used for comparison among different time points of groups, while two sample t test was used for comparison between the groups. Results On the 1 st day, 5 th day, 10 th day, and the 15 th day, the ADC ratios of the radiotherapy groups were 0.74 ±0. 15（n =8）, 1.04 ±0.09（n =7）, 1.43 ±0. 12 （n = 7 ）, 1.25 ± 0. 23 （n = 8 ） （F = 24. 221, P 〈 0. 01 ）, the corresponding ADC ratios of control groups were 0. 78 ±0.07（n =5）, 0.79 ±0.07（n=4）, 0.83 ±0. 14（n =4）, 0.97 ±0. 19（n =4）. The ratios of ADC values for radiotherapy groups and control group were compared, and the t value was 0. 569 （ P 〉0.05）, 4.417（P〈0.05）, 7.259（P 〈0.01）, 1.957（P〉0.05） respectively for each time point. On the 1 st day, 5 th day, 10 th day, 15 th day, the apoptotic index of the radiotherapy groups were 0. 39 ±0. 13（n=8）, 0.29 ±0.08（n=7）, 0.28 ±0.07（n=7）, 0.58 ±0. 19（n=8,F=8. 128,P〈0.05）, while the corresponding apoptotic index of control groups were 0. 26 ±0. 13（n =5）, 0. 18 ±0. 03（n =4）, 0. 16 ±0. 06（n =4）, 0. 18

关 键 词：肝肿瘤 实验性 磁共振成像 弥散 细胞凋亡 

分 类 号：R735.7[医药卫生—肿瘤]