Quantitative 89Zr Immuno-PET for In Vivo Scouting of 90Y-Labeled Monoclonal Antibodies in Xenograft-Bearing Nude Mice

Journal of Nuclear Medicine

Gerard W.M. Visser¹  Iris Verel¹  Julliette van Eerd¹  Ronald Boellaard¹  Adriaan A. Lammertsma¹  Gordon B. Snow¹  Otto C. Boerman¹  Guus A.M.S van Dongen¹ 

关键词: ⁸⁹Zr;    PET;    monoclonal antibodies;    xenograft-bearing nude mice;    ⁹⁰Y;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Immuno-PET as a scouting procedure before radioimmunotherapy (RIT) aims at the confirmation of tumor targeting and the accurate estimation of radiation dose delivery to both tumor and normal tissues. Immuno-PET with 89Zr-labeled monoclonal antibodies (mAbs) and 90Y-mAb RIT might form such a valuable combination. In this study, the biodistribution of 89Zr-labeled and 88Y-labeled mAb (88Y as substitute for 90Y) was compared and the quantitative imaging performance of 89Zr immuno-PET was evaluated. Methods: Chimeric mAb (cmAb) U36, directed against an antigen preferentially expressed in head and neck cancer, was labeled with 89Zr using the bifunctional chelate N-succinyldesferrioxamine B (N-sucDf) and with 88Y using the bifunctional chelate p-isothiocyanatobenzyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (p-SCN-Bz-DOTA). The radioimmunoconjugates were coinjected in xenograft-bearing nude mice, and biodistribution was determined at 3, 24, 48, 72, and 144 h after injection. 89Zr was evaluated and compared with 18F in phantom studies to determine linearity, resolution, and recovery coefficients, using a high-resolution research tomograph PET scanner. The potential of PET to quantify cmAb U36-N-sucDf-89Zr was evaluated by relating image-derived tumor uptake data (noninvasive method) to 89Zr uptake data derived from excised tumors (invasive method). Results: 89Zr-N-sucDf-labeled and 88Y-p-SCN-Bz-DOTA-labeled cmAb U36 showed a highly similar biodistribution, except for sternum and thighbone at later time points (72 and 144 h after injection). Small differences were found in kidney and liver. Imaging performance of 89Zr approximates that of 18F, whereas millimeter-sized (19–154 mg) tumors were visualized in xenograft-bearing mice after injection of cmAb U36-N-sucDf-89Zr. After correction for partial-volume effects, an excellent correlation was found between image-derived 89Zr tumor radioactivity and γ-counter 89Zr values of excised tumors (R2 = 0.79). Conclusion: The similar biodistribution and the favorable imaging characteristics make 89Zr a promising candidate for use as a positron-emitting surrogate for 90Y.

【 授权许可】

Unknown