Imaging HER2-positive metastatic esophagogastric cancer with 89Zr-trastuzumab PET and 18F-FDG PET.

4068 Background: Variations in HER2 expression between primary tumor and metastases may contribute to drug resistance in HER2-positive mEG cancer. Whole body imaging with 89 Zr-trastuzumab PET has a potential advantage over single site biopsies as it can non-invasively assess variations in HER2 expression and target engagement. 89 Zr-trastuzumab PK, biodistribution and dosimetry in mEG cancer were previously published by our group (O’Donoghue,...