An Investigational Scan (64Cu-DOTA-Trastuzumab PET/MRI) in Imaging Patients With HER2+ Breast Cancer With Brain Metastasis

This study is testing a new type of imaging scan — a PET/MRI scan using a specially designed tracer called 64Cu-DOTA-Trastuzumab — to see if it can better detect breast cancer that has spread to the brain in patients with HER2-positive breast cancer. **You may be eligible if...** - You are a woman 18 or older with HER2-positive metastatic breast cancer - Your cancer has spread to the brain - You are planned to receive a drug called fam-trastuzumab deruxtecan - Your heart pumping function and blood counts are within acceptable ranges **You may NOT be eligible if...** - You have kidney problems (creatinine clearance below a certain threshold) - Your blood counts (white cells, platelets, hemoglobin) are too low - Your liver function tests are significantly abnormal Talk to your doctor to see if this trial is right for you.