PT  - JOURNAL ARTICLE
AU  - Mortimer, Joanne E.
AU  - Bading, James R.
AU  - Frankel, Paul H.
AU  - Carroll, Mary I.
AU  - Yuan, Yuan
AU  - Park, Jinha M.
AU  - Tumyan, Lusine
AU  - Gidwaney, Nikita
AU  - Poku, Erasmus K.
AU  - Shively, John E.
AU  - Colcher, David M.
TI  - Use of <sup>64</sup>Cu-DOTA-Trastuzumab PET to Predict Response and Outcome of Patients Receiving Trastuzumab Emtansine for Metastatic Breast Cancer: A Pilot Study
AID  - 10.2967/jnumed.121.262940
DP  - 2022 Aug 01
TA  - Journal of Nuclear Medicine
PG  - 1145--1148
VI  - 63
IP  - 8
4099  - http://jnm.snmjournals.org/content/63/8/1145.short
4100  - http://jnm.snmjournals.org/content/63/8/1145.full
SO  - J Nucl Med2022 Aug 01; 63
AB  - We hypothesized that functional imaging with 64Cu-DOTA-trastuzumab PET/CT would predict the response to the antibody–drug conjugate trastuzumab–emtansine (T-DM1). Methods: Ten women with metastatic human epidermal growth factor receptor 2–positive breast cancer underwent 18F-FDG PET/CT and 64Cu-DOTA-trastuzumab PET/CT on days 1 and 2 before treatment with T-DM1. Results: T-DM1–responsive patients had higher uptake than nonresponsive patients. Day 1 minimum SUVmax (5.6 vs. 2.8, P < 0.02), day 2 minimum SUVmax (8.1 vs. 3.2, P < 0.01), and day 2 average SUVmax (8.5 vs. 5.4, P < 0.05) for 64Cu-DOTA-trastuzumab all favored responding patients. Tumor-level response suggested threshold dependence on SUVmax. Patients with a day 2 minimum SUVmax above versus below the threshold had a median time to treatment failure of 28 mo versus 2 mo (P < 0.02). Conclusion: Measurement of trastuzumab uptake in tumors via PET/CT is promising for identifying patients with metastatic breast cancer who will benefit from T-DM1.