Unusual Soft Tissue Uptake of F-18 Sodium Fluoride in Three Patients Undergoing F-18 NaF PET/CT Bone Scans for Prostate Cancer.

Three males aged 71 to 80 years with known stage IV metastatic prostate cancer underwent F-18 sodium fluoride (NaF) PET/CT to assess osseous metastatic disease burden and stability. In addition to F-18 NaF avid known osseous metastases, each patient also exhibited increased F-18 NaF activity in soft tissues. The first patient exhibited multiple F-18 NaF avid enlarged retroperitoneal and pelvic lymph nodes on consecutive PET/CT scans. The second patient demonstrated an F-18 NaF avid thyroid nodule on consecutive PET/CT scans. The third patient exhibited increased F-18 NaF activity in a hepatic metastasis.