Whole-body F-18 sodium fluoride PET-CT in a patient with renal cell carcinoma.

A 59-year-old male with metastatic renal cell cancer presented with pain in the right heel. Radiographs showed a large lytic lesion in the right calcaneus, suspicious for bone metastasis. For a comprehensive morphologic and scintigraphic evaluation, a whole-body F-18 sodium fluoride (NaF) PET-CT was acquired. All lytic lesions seen on the CT showed intense peripheral fluoride uptake. Five fluoride avid lesions were not seen on the CT scan. Eight foci of mild to moderate fluoride activity were identified as degenerative joint disease on the CT scan. Intense peripheral NaF uptake was seen in the lytic lesion in the right calcaneus, which was later proven by needle biopsy to be metastasis from renal cell cancer.