Increased PSMA Expression in Castration-Resistant Prostate Cancer Metastases 3 Months After Initiation of Enzalutamide Indicated by 18F-DCFPyL PET/CT

Radioisotope-labeled prostate-specific membrane antigen PET/CT is increasingly used for detection of prostate cancer most often in the setting of biochemical recurrence or in primary staging. This report shows increased PSMA expression in lymph node metastases 3 months after initiation of enzalutamide for castration-resistant prostate cancer, whereas lymph node volume and serum prostate-specific antigen decreases over time. This case demonstrates that increasing F-18-DCFPyL uptake after initiation of androgen deprivation therapy should not be confused with disease progression.