Use of 64 Cu-DOTA-Trastuzumab PET to Predict Response and Outcome of Patients Receiving Trastuzumab Emtansine for Metastatic Breast Cancer: A Pilot Study

• Published in: Journal of Nuclear Medicine Vol. 63; no. 8; pp. 1145 - 1148
• Main Authors: Mortimer, Joanne E, Bading, James R, Frankel, Paul H, Carroll, Mary I, Yuan, Yuan, Park, Jinha M, Tumyan, Lusine, Gidwaney, Nikita, Poku, Erasmus K, Shively, John E, Colcher, David M
• Format: Journal Article
• Language: English
• Published: United States 01-08-2022
• Subjects: Ado-Trastuzumab Emtansine; Antibodies, Monoclonal, Humanized - therapeutic use; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - drug therapy; Breast Neoplasms - metabolism; Female; Heterocyclic Compounds, 1-Ring; Humans; Pilot Projects; Positron Emission Tomography Computed Tomography; Receptor, ErbB-2 - metabolism; Trastuzumab - therapeutic use; breast cancer; breast PET; breast; PET; oncology
• ISSN: 0161-5505; 1535-5667; 2159-662X
• DOI: 10.2967/jnumed.121.262940

We hypothesized that functional imaging with
Cu-DOTA-trastuzumab PET/CT would predict the response to the antibody-drug conjugate trastuzumab-emtansine (T-DM1).
Ten women with metastatic human epidermal growth factor receptor 2-positive breast cancer underwent
F-FDG PET/CT and
Cu-DOTA-trastuzumab PET/CT on days 1 and 2 before treatment with T-DM1.
T-DM1-responsive patients had higher uptake than nonresponsive patients. Day 1 minimum SUV
(5.6 vs. 2.8,
< 0.02), day 2 minimum SUV
(8.1 vs. 3.2,
< 0.01), and day 2 average SUV
(8.5 vs. 5.4,
< 0.05) for
Cu-DOTA-trastuzumab all favored responding patients. Tumor-level response suggested threshold dependence on SUV
Patients with a day 2 minimum SUV
above versus below the threshold had a median time to treatment failure of 28 mo versus 2 mo (
< 0.02).
Measurement of trastuzumab uptake in tumors via PET/CT is promising for identifying patients with metastatic breast cancer who will benefit from T-DM1.