18F-fluoride uptake in bone metastasis: morphologic and metabolic analysis on integrated PET/CT

The aim of our study was to evaluate detectability of bone metastatic lesions and evaluate the correlation between (18)F-fluoride uptake patterns on positron emission tomography (PET) and morphologic changes on CT using integrated PET/CT.

We performed whole-body (18)F-fluoride PET/CT staging for 27 patients with known cancer. Tumor types comprised breast (n = 7), prostate (n = 7), and others (n = 13). A total of 154 uptake lesions were evaluated. Both tracer uptake patterns determined by (18)F-fluoride PET and morphologic patterns based on CT findings such as morphologic changes, involved locations, and grades scored using five-point scale were compared with histologic tumor subtypes and clinical laboratory data.

CT patterns of metastatic lesion were lytic or unclassified in 26 lesions, sclerotic in 53 lesions, and mixed in 75 lesions. Multiple linear regression analysis revealed that metastatic bone lesions with high maximum standardized uptake value (SUVmax) tended to show sclerotic or mixed changes on CT (P < 0.0001), and were also distributed in bone cortex alone or both bone cortex and medulla (P < 0.0001).

In patients with bone metastasis, the lesions with sclerotic or mixed changes or located in bone cortex alone or both bone cortex and medulla tend to show high SUVmax on (18)F-fluoride PET/CT.