Differentiation of malignant and degenerative benign bone disease using 99mTc-citrate scintigraphy

Objective: To differentiate malignant and degenerative benign bone disease using 99mTc- citrate scintigraphy. Methods: Thirty-nine patients (92 lesions) with confirmed malignant bone disease or degenerative benign bone disease were studied, for which the results of 99mTe-methylene diphosphonate(99mTc- MDP) scintigraphy were positive. 99mTc-citrate scintigraphy was performed within a time interval of 2-7 days after 99mTc-MDP scintigraphy. Visual analysis and semiquantitative analysis were applied. Each lesion was scored as malignant or benign, which was independently verified, using conventional techniques (histopathology, X-ray, CT, MRI and clinical follow up). Results: In visual analysis of 99mTc-citrate imaging, most malignant lesions (35/48, 72.92%) clearly showed high radioactivity accumulation, while most benign lesions (39/44, 88.64%) had not obviously visible uptake of 99mTc-citrate. In semiquantitative analysis of 99mTc- citrate image, malignant lesions demonstrated a higher lesion-to-background radioisotope uptake ratio (RUR) than that of benign degenerative lesions (1.47 ± 0.42 vs. 1.09 ± 0.38, t=2.887, P<0.01), while RUR of 99mTc-MDP in the two groups is of the same (1.96 ± 0.25 vs. 1.87 ± 0.21, t=1.178, P>0.20). Conclusion: 99mTc- citrate scintigraphy is a promising method to differentiate malignant from benign degenerative lesions seen as areas of increased activity on 99mTc-MDP bone scintigraphy. (authors)