MRI导引与实时监控冷冻消融治疗兔VX2脑肿瘤  

Experimental study of cryoablation on rabbit＇s VX2 brain tumor under MRI guidance and real-time monitoring

作　　者：李成利[1] 张传臣[2] 谢国华[2] 王炜[1] 柳明[1] 吕玉波[1] 宋吉清[1] 

机构地区：[1]山东大学山东省医学影像学研究所MR介入中心,济南250021 [2]聊城市人民医院放射科

出　　处：《中华放射学杂志》2008年第6期650-654,共5页Chinese Journal of Radiology

基　　金：山东省科技攻关项目资助（2007GG3WZ02079）

摘　　要：目的探讨MR导引与实时监控下氩氦刀冷冻消融治疗兔VX，脑肿瘤的可行性。方法22只新西兰兔，全麻下通过颅骨钻孔种植瘤块的方法建立VX2脑肿瘤模型。脑肿瘤生长到最大径0．8cm，在MR实时导引和监控下对肿瘤进行消融治疗。制模成功并符合实验条件的兔20只，取4只进行预实验，以了解最佳冷冻时间。预实验兔2只肿瘤冷冻5min，2只冷冻10min，均为2个循环。治疗后牺牲动物进行病理检查，显示冷冻10min治疗效果好。另16只实验兔分为对照组与冷冻消融治疗组，每组8只。对治疗组兔脑肿瘤进行冷冻消融治疗10min，给予20％甘露醇静脉注射及地塞米松皮下注射，进行脱水及预防脑水肿处理；对照组兔不进行任何处理。分别于手术后瞬间、7、14及60d对2组兔行脑MR扫描，观察肿瘤体积及生存期。治疗组兔，分别在消融后瞬间、7、14dMR扫描后牺牲1只，剩余的在冷冻治疗后60dMR检测后全部牺牲，观察肿瘤组织冷冻消融后的病理变化。结果22只兔2只术中感染死亡（其中1只成瘤），制模成功并存活的20只。MR扫描T1WI呈略低信号，T2WI呈略高信号；增强扫描呈明显较均匀强化，肿瘤最大径线0．7～1．0cm；同期检查显示肿瘤大小较一致，形态规则。冷冻消融后肿瘤病理检查显示术后瞬间、7、14d消融区呈凝固性坏死表现，60d时呈液化性坏死表现。MRI显示的T1WI低或等信号、T2WI低信号区与病理检查的凝固性坏死区相对应；T1WI低信号、T2WI高信号与病理检查液化性坏死灶或周围水肿性改变相对应。大体病理标本可清晰显示冷冻消融区最大径线为1．0～1．5cm，而术中MRI显示的冰球最大径线范围为1．5～2．0cm。结论脑肿瘤氩氦刀冷冻消融治疗安全可行。Objective To verify the feasibility of cryoablation on rabbit brain tumor under interventional MRI guidance. Methods The procedures were performed under general anaesthesia. Twentytwo New Zealand white rabbit＇s brains were inoculated with VX2 tumor tissue through cranial holes. MR-guided cryoablation were conducted as preliminary experiment when diameter of brain tumor grew up to 0. 8 cm in size. Cryoablation lasted two cycles of 5 minutes freezing, in 2 rabbits, and of 10 minutes freezing in another 2 rabbits. After procedure and MR scanning, rabbits were executed. Specimens of rabbit＇s brain showed complete necrosis pathologically after cryoablation of cycles of 10 minutes freezing. The optimal parameters of cryoablation were defined. Except for the two rabbits that died of infection, the other 16 rabbits were divided into control group and therapeutic group. According to the optimal parameters of cryoablation, cryoablation of 10 minutes freezing were performed for rabbit brain tumors in therapeutic group. Venous injection of 20% mannitol and subcutaneous injection of dexamethasone were used for dehydration. None of rabbit brain tumors in the control group were treated. After cryoablation, MRI scanning was performed immediately, 7 days later, 14 days later and 60 days later, to observe the ablative area and the pathologic changes. The survival time was recorded. Results Brain tumors could be found in all New Zealand white rabbits after inoculation except two died of inflammation. The maximum diameter of brain tumors was from 0.7 to 1.0 cm. The tumors showed slight low signal on T1WI and slight high signal on T2WI as well as contrast enhancement after injection of Gd-DTPA. Pathologically eoagulative necrosis were observed after cryoablation immediately, 7 days and 14 days later, and liquefactive necrosis was found 60 days later. The correlation between MRI and pathologic appearance of tumors are consistent. The therapeutic area ranged from 1.0 to 1.5 cm . The maximium diameter of ice ball ranged from 1.5 to

关 键 词：磁共振成像 介入性 脑肿瘤 模型 动物 冷冻外科手术 

分 类 号：R686[医药卫生—骨科学]