Application of PET imaging with Cu for quantitative evaluation of radioimmunotherapy

放射免疫療法の定量評価へのCu PETイメージングの適用

飯田 靖彦*; 花岡 宏史*; 片渕 竜也*; 渡辺 智; 石岡 典子; 松橋 信平; 織内 昇*; 樋口 徹也*; 宮久保 満之*; 遠藤 啓吾*

Iida, Yasuhiko*; Hanaoka, Hirofumi*; Katabuchi, Tatsuya*; Watanabe, Satoshi; Ishioka, Noriko; Matsuhashi, Shimpei; Oriuchi, Noboru*; Higuchi, Tetsuya*; Miyakubo, Mitsuyuki*; Endo, Keigo*

Cu is one of the most attractive candidate emitter for radioimmunotherapy (RIT). Cu releases positron emitter (0.653 MeV, 18%) as well as middle energy -particles (0.578 MeV, 37%), so it can be applied for diagnostic imaging with PET. PET is superior in quantitative measurement and suitable for evaluation of therapeutic effect with RIT. PET can also directly estimate radiation dose of RIT. In this study, we prepared a radioimmunoconjugate, NuB2, anti-CD20 monoclonal antibody (mAb), labeled with Cu, and evaluated its potential for PET imaging with RIT. NuB2 was labeled with Cu. For in vivo studies, SCID mice bearing CD20 tumor were used. After administration, biodistribution and PET imaging were performed. For the results of biodistribution, Cu-NuB2 was highly accumulated to CD20 tumor, and PET images could show the same results. From these date, the use of Cu for PET imaging has potential for accurately evaluation of therapeutic effect of RIT.