Does quantitative analysis of three-dimensional power Doppler angiography have a role in the diagnosis of malignant pelvic solid tumors? A preliminary study

OBJECTIVE: To investigate the role of a simplified method for the three-dimensional (3D) quantification of tumor vascularity in the differential diagnosis of solid pelvic masses. METHODS: Twenty-four patients with a solid pelvic mass on B-mode ultrasound evaluation underwent 3D power Doppler evaluation before surgery. The volume of interest was obtained by drawing the largest section of the mass in three orthogonal planes. The following 3D vascular parameters were calculated for all patients: relative color, average color and flow measure. Receiver-operating characteristics curve analysis was used to choose the best cut-off value. The overall agreement between the test result and the actual outcome was calculated using kappa statistics. RESULTS: Fifteen of 24 subjects were found to have pelvic malignancy. The relative color and the flow measure were significantly higher in malignant (9.7 (8.98) and 8.95 (8.78) (median (interquartile range (IQR)), respectively) than in benign masses (2 (4.42) and 1.79 (4.71), respectively; P < 0.05) but there was no difference in the average color. The best cut-off values of relative color and flow measure were 3.2 and 2.8, respectively. The use of relative color showed a sensitivity of 80% with a specificity of 67% with an overall agreement that was higher, though only marginally so, than that of qualitative 3D power Doppler (kappa = 0.47 and 0.44, respectively). CONCLUSIONS: In a small group of pelvic masses that appear malignant on B-mode ultrasonography, the use of 3D quantification of tumor vascularity yields a diagnostic accuracy that is similar to that of subjective evaluation of vascularity. We suspect, however, that the quantitative method will produce more consistent results between operators