放射性药物99mTc-HL91在实验性小鼠G422移植性脑胶质瘤模型的研究

目的 利用实验性小鼠G422移植性脑胶质瘤模型, 进行^99mTc- HL91体内分布和乏氧显像研究, 以探讨其在脑肿瘤诊断中应用的可能性。方法 6只模型小鼠分别于注射^99mTc- HL91后即刻、1、2、3、4、6、7、8小时行全身静态后位平面显像。于注射后4、8小时各处死3只。取血, 并剥离脏器及肿瘤组织, 称重, 测量放射性计数, 计算不同时相肿瘤与血液和各脏器的单位重量放射性比值。在全身静态平面显像图上, 利用感兴趣区技术, 分别计算不同时相肿瘤与头部(T/H)、对侧相应部位(T/A)、胸部(T/C)放射性比值。结果 注射^99mTc- HL91后自1小时起, 肿瘤部位放射性增高, 显影清晰；2小时更为明显, 3小时后较2小时变化不大。2小时T/H、T/A、T/C放射性比值分别是2.93±0.51、4.86±0.79、2.00±0.35, 与即刻及1小时比较差异均有显着性(P<0.05～P<0.01).体外测量肿瘤/血液、肌肉、脑及胸部脏器单位重量放射性比值较高, 肿瘤/腹部脏器单位重量放射性比值较低。结论 ^99mTc- HL91在移植性小鼠脑胶质瘤瘤组织中滞留增加, 清除延缓。进行乏氧显像以注射后2小时为宜。且仅适用于头颈部、胸部、骨骼及软组织肿瘤，而不能用于腹部肿瘤。

Experimental study of hypoxia imaging agent 99m Tc-HL91 in mice bearing glioblastoma G422

Objective To evaluate the ability of detecting cerebral tumor by ^99m Tc-HL91 in mice bearing glioblastoma G422. Methods Six model mice underwent static whole body planar imagings at once and at 1,2,3,4,6,7,8h postinjection of ^99m Tc-HL91.Three mice each were killed at 4h and 8h,respectively.The tumor,blood and organs were removed,weighted and the radioactivity was measured.ROIs were drawn around tumor,head,contralateral axilla and chest in whole body planar images,and the radioactivity ratios of tumor to head (T/H),contralateral axilla (T/A) and chest (T/C) were calculated. Results Increased tumor activity was indentified in static whole body planar images since 1h postinjection.At 2h postinjection,T/H,T/A and T/C were 2.93±0.51,4.86±0.79 and 2.00±0.35 respectively,which were significantly higher than those at once and at 1h postinjection ( P <0.05, P <0.01).The radioactivity ratios in per unit weight of tumor to blood,muscles,brain,heart and lungs at 4h postinjection were much higher than those of tumor to liver,spleen,stomach,intestines and kidneys. Conclusion Retention ratio of ^99m Tc-HL91 in tumor tissue of mice bearing glioblastoma G422 is increased and clearance rate is decreased. ^99m Tc-HL91 imaging is suitable for gliblastoma at 2h postinjection.It is appropriate to image tumors in head,neck,thorax,bone and soft tissues,but not in abdominal area.