A 78-year-old man receiving bicalutamide for prostate cancer was referred for a PSMA PET/CT scan to evaluate his gradually rising prostate-specific antigen level. The PSMA PET/CT revealed gynecomastia with radiotracer uptake in bilateral breast parenchyma, a known but rarely reported effect of bicalutamide monotherapy. This scan also demonstrated metastatic progression of his disease in bone and lymph nodes, and he was started on leuprolide injections. Three months after a decrease in his testosterone level, the radiotracer uptake in his breast tissue had resolved, demonstrating that PSMA-avid bicalutamide-induced gynecomastia is reversible.
Clinical nuclear medicine. 2024 Feb 07 [Epub ahead of print]
Miguel Muniz, Daniel S Childs, Jacob J Orme, Geoffrey B Johnson, Oliver Sartor
From the Division of Medical Oncology., Division of Nuclear Medicine, Department of Radiology and Department of Immunology, Mayo Clinic, Rochester, MN.