Intense Diffuse Uptake of 68Ga-FAPI-04 in the Breasts Found by PET/CT in a Patient With Advanced Nasopharyngeal Carcinoma

The physiological uptake of 68Ga-FAPI-04 due to the change of the internal environment is little known. We report the case of a 45-year-old woman who was highly suspected to have advanced nasopharyngeal carcinoma. 18F-FDG and 68Ga-FAPI-04 PET/CT was performed for evaluating the disease. Both PET and CT with different tracers detected the primary nasopharyngeal carcinoma and metastases in right neck lymph nodes, liver, and bones. To our surprise, intense diffuse uptake of 68Ga-FAPI-04 was found in both breasts, which might be due to the hormone stimulation because the patient received 68Ga-FAPi-04 PET/CT just at the period of ovulation.