Objective: This retrospective study investigated the performance of whole-body bone scintigraphy combined with SPECT/CT and established a grading diagnostic criterion for bone metastases.
Methods: We summarized signs of whole-body bone imaging combined with SPECT in nuclear medicine and CT signs of corresponding parts. Then we established a diagnostic criterion for bone metastases by using whole-body bone scintigraphy combined with local SPECT/CT. The criterion is classified into five grades. 120 patients with a total of 141 lesions underwent whole-body bone scintigraphy and SPECT/CT. Two reviewers read the images according to the diagnostic criterion. With pathological diagnosis as the "gold standard", the diagnostic efficacy for bone metastases and the diagnostic agreement between the two reviewers were analyzed to validate the feasibility of the criterion. Diagnostic effectiveness was expressed in terms of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.
Results: The diagnostic accuracy of the two reviewers was 90.1% and 92.9% respectively, sensitivity was both 100%, specificity was 41.7% and 58.3%, positive predictive value was 89.3% and 92.1%, and negative predictive value was both 100%. The kappa value of the diagnostic tests performed by the two reviewers on whole-body bone scintigraphy combined with SPECT/CT was 0.919 (P < 0.001).
Conclusion: The grading diagnostic criterion for bone metastases by whole-body bone scintigraphy combined with SPECT/CT has high diagnostic accuracy and good consistency between reviewers, but the specificity was still low even with SPECT/CT.
Keywords: Bone metastases; Diagnostic; Malignant tumor; SPECT/CT.