Related Experiment Video
Updated: Jun 21, 2026
Ex Vivo Treatment Response of Primary Tumors and/or Associated Metastases for Preclinical and Clinical Development of Therapeutics
Published on: October 2, 2014
Early tumor response to Hsp90 therapy using HER2 PET: comparison with 18F-FDG PET
Peter M Smith-Jones1, David Solit, Farzana Afroze
1Nuclear Medicine Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10021, USA. smith-jp@mskcc.org
Unlabelled:
We compared (68)Ga-DOTA-F(ab')(2)-herceptin (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid [HER2 PET]) and (18)F-FDG PET for imaging of tumor response to the heat shock protein 90 (Hsp90) inhibitor 17-allylamino-17-demethoxygeldanamycin (17AAG).
Methods:
Mice bearing BT474 breast tumor xenografts were scanned with (18)F-FDG PET and HER2 PET before and after 17AAG treatment and then biweekly for up to 3 wk.
Results:
Within 24 h after treatment, a significant decrease in HER2 was measured by HER2 PET, whereas (18)F-FDG PET uptake, a measure of glycolysis, was unchanged. Marked growth inhibition occurred in treated tumors but became evident only by 11 d after treatment. Thus, Her2 downregulation occurs independently of changes in glycolysis after 17AAG therapy, and Her2 reduction more accurately predicts subsequent tumor growth inhibition.
Conclusion:
HER2 PET is an earlier predictor of tumor response to 17AAG therapy than (18)F-FDG PET.
