Heterogeneous Flare in Prostate-specific Membrane Antigen Positron Emission Tomography Tracer Uptake with Initiation of Androgen Pathway Blockade in Metastatic Prostate Cancer

Flares of increased prostate-specific membrane antigen (PSMA) tracer uptake on positron emission tomography scans are variably observed following initiation of hormone therapy for prostate cancer and do not necessarily represent disease progression. There was considerable variability in PSMA expression between patients, and further studies are needed to understand the factors controlling PSMA expression.