不同分子量^(99m)Tc-Dx的比较及初步淋巴显像应用

Lymphoscintgraphy with ^(99m)Tc-dextran-comparison of different molecular weight and preliminary clinical studies

对平均分子量为4、7、9和13.8万的^(99m)Tc标记大分子右旋糖酐(Dx)的研究表明,^(99m)Tc-Dx从注射位置向血液的渗透率,^(99m)Tc-Dx在肝、肾等脏器中的浓集随Dx平均分子量增大而降低。而在淋巴结中的药物浓度则随Dx的分子量增大而增加。平均分子量9万的^(99m)Tc-Dx在大鼠腘淋巴结与肝、肾、血的放射性浓度之比,在注药后2h分别高达1924、938和6087。完全可以满足淋巴显像的要求。30例^(99m)Tc-DX-90临床试用证明:^(99m)Tc-Dx淋巴显像具有显像速度快、图象清晰、非创伤性、使用方便等优点,是一个有前途的淋巴显像剂。

Four 99mTo-labelled dextrans with average molecular weights of 40000,70000, 90000, and 138000 has been evaluated. The study of biodistribution and tracer kinetics in rats demonstrated that, 99mTc-Dx(90) was much better than the others with high uptake of lymph nodes, low penetrating rate from injection site to blood, and excellent target/nontarget organ ratios. The preliminary clinical studies(in 20 normal and 10 patients) were also reported. Following interdigital injection of 0.5-1.0 ml Tc-99m-Dx(90) (about 57MBq), it reached the knee, inguinal or axilla nodes in 5.0±1.2, 10±2.0, and 15±3.0 min respectively.High quality imagings were obtained in all cases. It is concluded that 99mTc-Dx(90) is a very promising lymph system imaging agent.