Tracer uptake patterns depend on morphologic changes in metastatic bone tumors: Evaluation with F-18 NaF PET/CT

Objectives To evaluate the correlation with NaF uptake patterns and CT findings in 20 cancer patients who underwent NaF PET/CT.

Methods NaF PET/CT was performed on 20 cancer patients (12 male and 8 female; mean age, 64y) diagnosed with bone metastases by other imaging modalities such as bone scintigraphy, CT and MRI, or clinical follow up. A total of 114 uptake lesions were detected by NaF PET/CT. We evaluated the correlation between tracer uptake patterns , CT findings (morphologic changes, involved locations, grades scored using five-point scale) ,laboratory data (ALP,LDH, serum calcium) and histologic subtypes.

Results The SUVmax of osteoblastic or mixed-type lesions was statistically higher than those of osteolytic lesions or lesions without CT change (p<0.0001). The SUVmax of lesions involved area of bone cortex or both cortex and medulla were statistically higher than those of bone medulla alone (p<0.0001). There were moderate correlation among the SUVmax and morphologic changes at CT, involved locations (rs=0.363, p<0.0001), CT gradings (rs=0.314, p<0.0001). There were no significant differences between the SUVmax and laboratory data nor histologic subtypes. Multiple logistic regression analysis revealed that metastatic bone lesions with high SUV tend to show osteoblatic or mixed-type changes at CT (p=0.005), and also distributes in bone cortex alone or both bone cortex and medulla (p=0.001).

Conclusions The lesions with osteoblatic or mixed type changes or the lesions located in bone cortex alone or both bone cortex and medulla tend to show high SUVmax at NaF PET/CT.