Accuracy of fluorodeoxyglucose-positron emission tomography for diagnosis of single bone metastasis: comparison with...

The aim of this study was to compare the accuracy of fluorodeoxyglucose-positron emission tomography (FDG-PET) with bone scan for diagnosis of single bone metastasis using a semiquantitative method.

Seventy-six patients with suspected single bone metastasis, who underwent both FDG-PET and a bone scan, were selected. The number and location of lesions detected upon both FDG-PET and bone scan were recorded, and the lesions were compared using the McNemar test. For semiquantitative analysis, a maximum (max) standard uptake value (SUV) of 2.5 was used as the positive cutoff value for metastasis. The difference in max SUV value among 3 groups (osteolytic, osteoblastic, and benign lesions) was assessed using the Student-Newman-Keuls method. Biopsy results, other imaging findings (multirow detector computed tomography, magnetic resonance imaging), and the patient's clinical course were used as references.

There were 47 single bone metastases and 29 benign lesions. The sensitivity, specificity, and accuracy of bone scans for diagnosing bone metastases were 89%, 41%, and 71%, respectively, and those of FDG-PET were 85%, 52%, and 72%, respectively. These data were not significantly different (P > 0.05). Using a max SUV of 2.5 as the positive cutoff value for metastasis, the specificity and accuracy of FDG-PET, 83% for each, improved. When classifying bone metastasis as osteoblastic or osteolytic, the max SUV was significantly higher in osteolytic metastasis than in osteoblastic and benign lesions (P = 0.001).

Fluorodeoxyglucose-positron emission tomography (FDG-PET) using the semiquantitative parameter SUV improves the diagnostic ability to differentiate between single bone metastases and benign lesions.