PT  - JOURNAL ARTICLE
AU  - Sang-Keun Woo
AU  - Jingyu Kim
AU  - Sang LIm
AU  - Ilhan Lim
TI  - <strong>Compare of <sup>225</sup>Ac and <sup>211</sup>At alpha particle therapeutic effect in HER2 positive breast cancer</strong>
DP  - 2020 May 01
TA  - Journal of Nuclear Medicine
PG  - 1314--1314
VI  - 61
IP  - supplement 1
4099  - http://jnm.snmjournals.org/content/61/supplement_1/1314.short
4100  - http://jnm.snmjournals.org/content/61/supplement_1/1314.full
SO  - J Nucl Med2020 May 01; 61
AB  - 1314Purpose: The targeted alpha therapy attempts to deliver radiation selectively to tumor while minimizing toxic effect in normal region. In this study, we estimate the internal dosimetry of 225Ac/211At-NOTA-trastuzumab in HER2 positive breast cancer using 64Cu-NOTA-trastuzumab PET images. Methods: The preclinical 64Cu-NOTA-trastuzuman PET images were acquired using small animal PET/CT system (Inveon, Siemens Healthcare) on mouse (n = 4) at 6, 24, and 48 hour after intravenous injection. The clinical 64Cu-NOTA-trastuzumab PET image was acquired using PET/CT scanner (GE Discovery 710 scanner, GE system) on adult female (n = 3) at 1, 24, 48 hour after injection 64Cu-NOTA-trastuzumab. We compared extrapolated human dosimetry, human dosimetry, and image-based monte carlo simulation dosimetry methods. Human effective dose was evaluated OLINDA 2.1 (Hermes medical solutions) and the image-based effective dose was performed by Monte Carlo simulation (MC). Results: The mouse 64Cu-NOTA-trastuzumab data extrapolated human effective dose, human effective dose, and image-based MC effective dose were 8.9E-03, 8.4E-03, and 9.4E-03 mGy/MBq, respectively. The MC based 64Cu human effective dose was 11% difference of human effective dose. Compare the human absorbed dose in tumor of 225Ac was 7.33E+00 and 64Cu was 1.75E-02 mSv/MBq. According to the calculated result, 225Ac labeled NOTA-trastuzumab effects the tumor about 4.19E+02 times than 64Cu-NOTA-trastuzumab. Likewise, 211At labeled trastuzumab effect tumor cell about 1.01E+02 times than 64Cu-NOTA-trastuzumab. Conclusions: The three different methods were no significant differences in normal organ. According to the MC based tumor absorbed dose of 225Ac was show that three times therapeutic effect than 211At -NOTA-trastuzumab.