J Nucl Med 2002 Apr;43(4):510-8
The role of quantitative (18)F-FDG PET studies for the differentiation of
malignant and benign bone lesions.
Dimitrakopoulou-Strauss A, Strauss LG, Heichel T, Wu H, Burger C, Bernd L,
Ewerbeck V.
The role of quantitative (18)F-FDG PET studies for the differentiation of benign
and malignant bone lesions is still an open question. METHODS: Our evaluation
included 83 patients with 37 histologically proven malignancies and 46 benign
lesions. Thirty-five of the 46 benign lesions were histologically confirmed. The
(18)F-FDG studies were accomplished as a dynamic series for 60 min. Evaluation
of the (18)F-FDG kinetics was performed using the following parameters:
standardized uptake value (SUV), global influx (Ki), computation of the
transport constants K1-k4 with consideration of the distribution volume (VB)
according to a 2-tissue-compartment model, fractal dimension based on the
box-counting procedure (parameter for the inhomogeneity of the tumors). RESULTS:
The mean SUV, the vascular fraction VB, K1, and k3 were higher in malignant
tumors compared with benign lesions (t test; P < 0.05). Although the
(18)F-FDG SUV was helpful to differentiate benign and malignant tumors, there
was some overlap, which limited the diagnostic accuracy. On the basis of the
discriminant analysis, the SUV alone showed a sensitivity of only 54.05%, a
specificity of 91.30%, and a diagnostic accuracy of 74.70%. The fractal
dimension was superior and showed a sensitivity of 71.88%, a specificity of
81.58%, and an accuracy of 77.14%. The combination of SUV, fractal dimension,
VB, K1-k4, and Ki revealed the best results with a sensitivity of 75.86%, a
specificity of 97.22%, and an accuracy of 87.69%. Bayesian analysis showed
true-positive results at the level of 0.8 for a low prevalence of disease
(0.235) if the full kinetic data were used in the evaluation. CONCLUSION:
(18)F-FDG PET has a high specificity for the exclusion of a malignant bone
tumor. Evaluation of the full (18)F-FDG kinetics and the application of
discriminant analysis are required and can be used prospectively to classify a
bone lesion as malignant or benign.
