立体定位放射治疗对大鼠C6胶质瘤抗血管生成的MR灌注研究  

MR Perfusion Weighted Imaging of Antiangiogenesis in Rat C6 Glioma after Treatment with Stereotatic Radiosurgery

作　　者：张清波[1] 张仪[2] 冯晓源[3] 

机构地区：[1]南京医科大学第一附属医院放射科,江苏南京210029 [2]齐齐哈尔医学院第一附属医院放射科 [3]复旦大学附属华山医院放射科

出　　处：《实用放射学杂志》2010年第2期262-267,共6页Journal of Practical Radiology

摘　　要：目的评估立体定向放射治疗（SRS）对大鼠C6脑胶质瘤抗肿瘤血管生成的效果及MR灌注成像在疗效评价中的价值。方法20只尾状核区成功移植C6胶质瘤的大鼠。随机分为对照组（A组）和治疗组（B组）各10只，A组大鼠不予治疗，B组大鼠于肿瘤接种4周后行SRS治疗。B组于治疗前当日和治疗后1周分别在吸入高浓度CO2混合气体前后进行MR灌注成像（PWI）检查，扫描前测定大鼠的相关血气指标。检查结束处死大鼠并取脑固定，行HE染色FⅧ和SMA免疫组化染色。结果B组大鼠接受SRS治疗后1周肿瘤显著缩小。所有大鼠在吸入高浓度CO2混合气体后，血液CO2分压均明显升高，血浆pH值降低。B组大鼠在接受SRS治疗1周后，肿瘤实质所测灌注值较治疗前明显降低（rrCBV：t=7．478，P=0；rrCBF：t=10．13，P=0），无灌注的囊变区范围扩大。吸入高浓度COz混合气体前后，B组治疗后的肿瘤rCBV和rCBF的变化率较治疗前明显升高（rCBV变化率：t=12．27，P＝0；rCBF变化率：t=6．364，P=0．00013）。治疗后B组肿瘤实质MVD显著低于A组（t=3．466，P=0．001）。SMA染色阳性血管计数，2组间无显著差异（t=0．513，P=0．614）。A组大鼠肿瘤平均SMA计数／MVD计数比明显低于放疗后B组大鼠（t=2．373，P=0．014）。结论SRS可以明显抑制大鼠C6胶质瘤的血管生成，含平滑肌成分的肿瘤血管对SRS不敏感。Objective To analyze the antiangiogenic effect of stereotatic radiosurgery （SRS） in rat C6 gliomas using MR perfusion imaging（PWI） technique. Methods Twenty rats implanted with C6 glioma cells in the brain were randomly assigned into group A （without any therapy） and group B which underwent SRS therapy 4 weeks after implantation. PWI was performed to measure the regional cerebral blood volume （rCBV） and regional cerebral blood flow （rCBF） in tumor＇s region before therapy in all rats and 1 week later in group B. PWI sequence was applied pre- and post-inhalation of a mixture of 10% CO2 and 90% air. rCBV and rCBF were analyzed. PaCO2 and blood PH values were monitored before and aftermixed gas inhalation. All the MRI examination were carried out at a 3.0T magnet. The rats were sacrificed after MRI examination. Microvessel density （MVD） and number of mature vessels （with muscle layer） were measured histologically using immunohistochemical staining for factor Ⅷ and smooth muscle actin （SMA）. PWI data, and pathological results were analyzed statistically. Results The size of tumors in group B remarkably decreased with obvious necrotic area in the center 1 week after SRS therapy. PH value decreased and PaCO2 increased significantly after mixed gas inhalation. Blood gas data changes in group B were not significantly different from that in group A. The rCBV and rCBF of tumor＇s core in group B declined greatly after SRS treatment. The necrotic area was dark in rCBV and rCBF maps, that suggested no blood supply in this region. After therapy, the changing rate of rCBV and rCBF pre-- and post--inhalation of gas in group B was greater than those in group A. The MVD of tumors in group B after treatment was statistically less than that in group A . The number of SMA positively stained vessels in group B was nearly equal to that in group A. The percentage of SMA（＋）/MVD in group B was significantly higher than that in group A. Conclusion SRS can inhibit the angiogenesis of rat C6 glioma,

关 键 词：胶质瘤 磁共振成像 灌注 大鼠 实验 

分 类 号：R739.41[医药卫生—肿瘤] R445.2[医药卫生—临床医学]