对-二羟基硼酰苯丙氨酸的99Tcm标记及其生物分布

对-二羟基硼酰苯丙氨酸(BPA)由于具有在肿瘤处富集的性质而用于硼中子俘获治疗(BNCT)。按文献方法合成了BPA，并用^99Tc^m对其标记，生成一种新的锝包合型螯合物BATO(Boronic acid adducts of technetium dioxime)配合物，并进行了^99Tc^m-DMGBPA配合物在小鼠体内的生物分布研究。实验结果表明，^99Tc^m-DMGBPA可以选择性富集在肿瘤处，并且清除较慢，在肿瘤中的放射性活度明显高于肌肉和心、肺、血液等组织。随着时间的延长，肿瘤／正常组织的摄入比在不断增加。最大值出现在摄入后4h，这时的R(肿瘤／肌肉)为6．0，R(肿瘤／血液)为4．5，R(肿瘤／心)为6．0，R(肿瘤／肺)为3．0，R(肿瘤／肝)为0．41，R(肿瘤／肾)为0．134。通过分子轨道理论计算推测了^99Tc^m-DMGBPA配合物可能的结构。

Labelling of 4-Dihydroxyborylphenylalanine(BPA) With 99Tcm and Biodistribution of 99Tcm-DMG-BPA

BPA(4-dihydroxyborylphenylalanine) has being used in clinical trials for treatment of cancer with boron neutron capture therapy (BNCT) technology for its selective accumulation in tumors. BPA is prepared according to the published synthetic procedure. A new BATO complex is synthesized with dimethylglyoxime, BPA, and ~(99)Tc~mO~-_4 as the starting materials via a template reaction. The biodistribution of ~(99)Tc~m-DMG-BPA is studied. The results demonstrate that the complex is selectively accumulated in tumor and slowly cleared from it, the uptake in tumor is higher than in blood, heart, muscle and most of the other organs. The uptake ratio of tumor-to-tissue increased along with time. At 4 hour after injection, the uptake ratio of tumor to muscle reached 6.0, tumor/blood 4.5, tumor/heart 6.0, tumor/lung 3.0, tumor/liver 0.41, and tumor/kidney 0.134. The possible molecular structure of ~(99)Tc~m-DMG-BPA complex is predicted by ab inito MO calculation.