[18F] F-GLN by PET/CT in Breast Cancer

Up to 40 patients will undergo approximately 60 minutes of dynamic PET scanning followed by up to 2 static skull-base to mid-thigh scans post injection of \[18F\] (2S,4R)4-fluoroglutamine (\[18F\]F-GLN). A baseline FDG-PET/CT will also be performed, either as a routine clinical staging/re-staging scan or as a research scan. If performed as a research scan, the scan may include an optional dynamic imaging session. Some subjects, who undergo systemic therapy as part of their clinical treatment, may also undergo an optional second \[18F\]F-GLN PET/CT to collect pilot data on the changes in \[18F\]F-GLN uptake in response to therapy. Subjects who undergo a second \[18F\]F-GLN PET/CT may have a second FDG-PET/CT, again either as a standard-of-care restaging study or as an optional research scan. The timing of the optional second PET scans will vary depending on the type of treatment the subject is receiving. If the subject moves during their scans, a low-dose CT attenuation may be repeated following the dynamic scan at the PI's discretion.