Effectiveness of quantitative bone SPECT/CT for bone metastasis diagnosis.

Objective: This study was conducted to investigate the utility of standardized uptake value (SUV) derived from bone single photon emission tomography/computed tomography (SPECT/CT) for diagnosing bone metastasis.

Subjects and methods: One hundred forty-seven patients with malignant cancer (breast or prostate cancer), joint disorders, primary skeletal disease, or cartilaginous bone neoplasms who underwent skeletal quantitative SPECT/CT were retrospectively investigated. Acquired data were classified as normal fourth lumbar vertebra, skeletal degenerative changes, or bone metastasis. Receiver operating characteristic (ROC) curves were used to determine the optimum cut-off value for SUVmax to distinguish among these diagnoses.

Results: Mean SUVmax values for the normal L4 bone (n=101), skeletal degenerative changes (n=47) and bone metastasis (n=64) groups were 4.47±1.66 (range 1.01-11.25), 6.99±2.58 (2.21-14.6), and 25.4±15.7 (3.88-98.87), respectively. Compared to the other two groups, SUVmax for the bone metastasis group was significantly higher (P<0.001). In the normal bone group, sensitivity, specificity and accuracy for discriminating bone metastasis were 96.3%, 95.1%, and 95.7% respectively, with a best SUVmax cut-off value of 7.40. For the skeletal degenerative changes group sensitivity, specificity and accuracy were 87.5%, 93.6%, and 90.4% respectively, with a best SUVmax cut-off value of 11.26.

Conclusion: Quantitative bone SPECT/CT may be useful for bone metastasis diagnosis.