Labelling of 4-Dihydroxyborylphenylalanine(BPA) With ~(99)Tc~m and Biodistribution of ~(99)Tc~m-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.