PT  - JOURNAL ARTICLE
AU  - Eduardo Aluicio-Sarduy
AU  - Todd E. Barnhart
AU  - Jamey Weichert
AU  - Reinier Hernandez
AU  - Jonathan W. Engle
TI  - Cyclotron-Produced <sup>132</sup>La as a PET Imaging Surrogate for Therapeutic <sup>225</sup>Ac
AID  - 10.2967/jnumed.120.255794
DP  - 2021 Jul 01
TA  - Journal of Nuclear Medicine
PG  - 1012--1015
VI  - 62
IP  - 7
4099  - http://jnm.snmjournals.org/content/62/7/1012.short
4100  - http://jnm.snmjournals.org/content/62/7/1012.full
SO  - J Nucl Med2021 Jul 01; 62
AB  - The aim of this work was to explore 132La as a PET imaging surrogate for 225Ac using a DOTA-based, tumor-targeting alkylphosphocholine (NM600). Methods: 132La was produced on a biomedical cyclotron. For in vivo experiments, mice bearing 4T1 tumors were administered 132La-NM600, and PET/CT scans were acquired up to 24 h after injection. After the last time point, the ex vivo tissue distribution was measured to corroborate the in vivo PET data. The ex vivo tissue distribution in mice was determined at 4 and 24 h after injection of 225Ac-NM600. Results: PET/CT images showed elevated, persistent 132La-NM600 uptake in the tumor. Low bone accumulation confirmed the in vivo stability of the conjugate. Ex vivo biodistribution studies validated the image-derived quantitative data, and the comparison of the 132La-NM600 and 225Ac-NM600 tissue distributions revealed a similar biodistribution for the 2 radiotracers. Conclusion: These findings suggest that 132La is a suitable imaging surrogate to probe the in vivo biodistribution of 225Ac radiotherapeutics.