Fluorine-18-fluorodeoxyglucose positron emission tomography in technetium-99m-hydroxymethylenediphosphate negative bone tumors

We have encountered two cases of bone tumors with high 18 F-fluorodeoxyglucose (FDG) uptake and negative 99m Tc-HMDP bone scintigraphy, including a patient with myeloma and a patient with a metastatic bone tumor from esophageal cancer. Bone scintigraphy with a 99m Tc-phosphate complex reflects osteoblastic activity in the bone tissue surrounding the tumor, whereas the accumulation of FDG is associated with the metabolic activity of the tumor itself. An FDG-PET study can therefore be used as a complementary study for the detection and follow-up of bone tumors when a 99m Tc-phosphate bone scintigram is negative