磁共振扩散加权成像监测不同剂量单次照射兔VX2肝癌的疗效  

Diffusion weighted imaging for monitoring the therapeutic effect of single irradiation with different doses in hepatic VX2 tumors rabbit model

作　　者：吴红珍[1] 江新青[1] 吴梅[1] 陈亮[1] 魏新华[1] 郭媛[1] 

机构地区：[1]广州市第一人民医院放射科,广州510180

出　　处：《放射学实践》2014年第6期631-634,共4页Radiologic Practice

基　　金：广东省科技厅基金项目(2004B36001043);广州市医药卫生科技项目(20131A011003);广州市医药卫生科技项目(201102A213105);广东省科技计划项目(病毒性肝炎;肝硬化;肝癌MR弥散成像的实验与临床研究)

摘　　要：目的:通过DWI监测单次不同剂量照射下兔VX2肝癌的改变,并与病理比较。方法:40只兔VX2肝癌待肿瘤直径≥1cm时,随机分为2组行立体定向放疗,放疗剂量分别为10Gy、20Gy,单次放疗,放疗后不同时间点1d、5d、10d、15d分别行MR扫描,测量VX2肿瘤、肝脏感兴趣区(ROI)的ADC值,并计算两者比值。标本采用DNA缺口末端标记(TUNEL)法检测计算凋亡指数,并进行统计学分析。结果:40只肝癌模型共发现48个病灶。放疗后1d、15d10Gy组与20Gy组ADC比值、凋亡指数的差异无统计学意义(P>0.05),放疗后5d、10d10Gy组与20Gy组ADC比值、凋亡指数有显著性差异(P<0.05),认为20Gy组ADC比值显著高于10Gy组。结论:DWI可以从分子水平监测不同剂量放疗后VX2肝癌的动态变化,适当提高放疗剂量可以使细胞凋亡增加,细胞坏死、崩解更彻底,但有可能增加了放疗毒性。Objective：To evaluate the changes of hepatic VX2 tumors in campariation of the results of DWI and pathology after different doses of single stereotactic radiotherapy.Methods：When the tumor ≥1cm in diameter,40 hepatic VX2 tumor models were randomly divided into 2 groups for single radiation dose of 10Gy and 20 Gy respectively.MR-DWI scanning was performed was calculated at different time points,one day,5 days,10 days,15 days respectively after radiation therapy.ADC values were measured by choosing the ROI of the VX2 tumor tissue and normal liver tissue respectively,and then the ADC ratio of tumor tissue and normal liver tissue was calculated.The apoptotic index of specimen was calculated by DNA Nick end labeling （TUNEL）method,and statistical analysis was performed.Results：Fourty rabbit models of hepatic VX2 tumors were implated successfully and 48 lesions were detected.One day and 15 days after radiotherapy,these was no significant difference of ADC ratio and apoptotic index between 10Gy and 20Gy group （P〉0.05）,while 5 days and 15 days after radiotherapy,these was significant difference of ADC ratio and apoptotic index between 10Gy and 20Gy group （P〈0.05）.Conclusion：MR-DWI may help to reflect the dynamic changes of the molecular level at different time points for hepatic VX2 tumors after radiotherapy.The appropriate increased radiation dose could increased apoptosis,cell necrosis and disintegration could be more thorough,but it may increase radiation injury.

关 键 词：磁共振成像 肝肿瘤 扩散磁共振成像 模型 动物 放射疗法 辅助 

分 类 号：R445.2[医药卫生—影像医学与核医学] R735.7[医药卫生—诊断学]